Caribbean Environment Programme
United Nations Environment Programme
Assessment of the Economic Impacts of Hurricane Gilbert on
Coastal and Marine Resources in Jamaica
CEP Technical Report No.4
1989
...Hurricane Gilbert...
TABLE OF CONTENTS
Page
List of Figures
List of Tables
Summary
1. INTRODUCTION
1.1. Survey of Hurricane Damage
1.2. Terms of Reference
2. METHODOLOGY
2.1. Resources to be Considered
2.2. Data Sources and Data Collection
2.3. Ecological Assessment
2.4. Economic Assessment
3.
IDENTIFICATION OF IMPACTS
3.1. Beaches
3.2. Coastal Water Quality
3.3. Coral Reefs
3.4. Seagrass Beds
3.5. Mangrove and other Wetlands
3.6. Littoral Woodland and Strand Vegetation
3.7. Fishery Resources
3.8. Seabirds and Shorebirds
4.
FRAMEWORK FOR ECONOMIC ASSESSMENT OF THE IMPACTS
4.1. Economic Worth (Market and Non-Market) of the Resources
4.2. Estimation of Economic Losses
4.3. Economics of Recovery and Damage Prevention
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CEP Technical Report No. 4
5. DISCUSSION
5.1. Utility of the Assessment
5.2. Priority Areas for Recovery Effort
5.3. Key Areas for Marine Resources Research and Management Effort
6. ACKNOWLEDGEMENTS
7. REFERENCES
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...Hurricane Gilbert...
APPENDICES
Page
1.
Aiken, K.A.
Hurricane Gilbert and its Effect on Fishery Resources
2.
Alleng, G.
Hurricane Damage at Port Royal
3.
Bacon, P. R. Survey and Assessment of Hurricane Damage to Wetlands
4.
Clarke, P.
Post Hurricane Gilbert Report: Llandovery and Port Royal
5.
Greenaway, Physical and Chemical Effects of Hurricane Gilbert on the
A.M.
Wetland Adjacent to Wyndham Rosehall Hotel
6.
Jones, M.A. Effect of Hurricane Gilbert on Beaches and the Status of
Oil Pollution
7.
NRCD
Extracts from NRCD File 11/2/7, Hurricane Gilbert 1988
8.
USAC
UWI Sub-Aqua Club Survey of Extent of Damage at
Ocho Rios Marine Park due to Hurricane Gilbert
9.
Woodley, J.D. The Effects of Hurricane Gilbert on Coral Reefs in the
Discovery Bay
10.
Wright, S.
Effects of Hurricane Gilbert on Selected Oyster Culture Sites
11.
List of Papers on Hurricane Effects on Coastal and Marine Resource Areas in
Jamaica
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CEP Technical Report No. 4
LIST OF FIGURES
Fig.
No.
Caption
Page
A1.1.
Fishing Areas of Jamaica and 200m Isobath
A3.1.
Wetland Locations
A3.2.
Percentage Defoliation, Great Salt Pond
A3.3.
Damage to Conocarpus, Terminalia and Coconut at Mammee Bay
A3.4.
Minor Wind Damage to Fringe Rhizophora at Priory
A3.5.
Sand Thrown into Wetland at Llandovery
A3.6.
Seagrass Blade Debris Thrown into Fringe Rhizophora at
Llandovery
A3.7.
Littoral Woodland, including Conocarpus and Laguncularia,
Uprooted at Pear Tree Bottom
A3.8.
Damaged Rhizophora at the Egret Roost at Pear Tree Bottom
A3.9.
Wind Damage to Tall Rhizophora Basin Forrest at Crater Lake,
Discovery Bay
A3.10.
Rhizophora Tree Bent above the Buttresses at Crater Lake,
Discovery Bay
A3.11.
Coral Debris Thrown into Wind Damaged Fringe Mangrove and
Littoral Woodland, Rio Bueno
A3.12.
Defoliation of Tall Rhizophora, Florida Lands, Falmouth
A3.13.
Tall Rhizophora Broken above the Buttresses, Florida Lands, Falmouth
A3.14.
Defoliated Avicennia Woodland, Falmouth
A3.15.
Uprooted Avicennia Trees, Salt Marsh
A3.16.
Defoliated and Felled Trees, Wyndham Rose Hall Wetland
A5.1.
Sampling Sites In Wetland at Wyndham Rose Hall
A6.1
Map of Jamaica Showing Sites Sampled before and after Hurricane Gilbert
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...Hurricane Gilbert...
Fig.
No.
Caption
Page
A7.1
Beach
Localities
A8.1.
USAC Dive Transect Locations
LIST OF TABLES
Page
A1.1.
Resources Considered in this Report
A1.2.
Terminology Used in this Report
A1.3.
Some Meteorological Features of Hurricane Gilbert
A5.1.
Water Level and Conductivity at Wyndham Rose Hall Wetland
A6.1.
Levels of Stranded Tar
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CEP Technical Report No. 4
SUMMARY
1.
Hurricane impacts on beaches, coastal water quality, coral reefs, sea-grass beds,
wetlands, coastal vegetation, fisheries and waterbirds are documented, following rapid
survey.
2.
Erosion of over 50% of beaches occurred, with damage worst on the east and north
coasts.
3.
Natural recovery of beaches is in progress.
4.
Coastal water quality deteriorated, especially as a result of sediment-laden terrestrial run-
off.
5.
Recovery of water clarity occurred in about three weeks, except near river mouths, where
high turbidity continues.
6.
Coral reef damage was disastrous on the east and north coast.
7.
The recovery of reefs since Hurricane Allen (1980) has been set back by Hurricane
Gilbert.
8.
There has been severe loss of all types of reef organisms, and some loss of reef fish.
9.
Seagrass beds were damaged only superficially.
10.
Mangroves were severely damaged, with loss of up to 60% of trees in some areas.
Damage is worst on the east and north coasts.
11.
Damage to mangroves was largely to upper parts of the trees, the ground and aquatic
habitats were less affected.
12.
Waterfowl and other wetland animals were little affected.
13.
Natural recovery of mangrove areas is proceeding.
14.
Coastal woodland and strand was severely damaged on the east and north coasts.
15.
Considerable loss of fishing gear and fisheries infrastructure occurred, particularly on the
east and north coasts.
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...Hurricane Gilbert...
16.
Artisanal fishing was disrupted for three to four months following Hurricane Gilbert.
17.
There is little evidence of damage to primary fisheries resources (scalefish, lobster,
conch, etc.).
18.
Oyster culture and artificial reef structures were damaged on the south coast.
19.
Damage to seabirds and shorebirds appears to be minimal.
20.
Available data is inadequate for accurate assessment of the economic impacts of
Hurricane Gilbert on coastal and marine resources in Jamaica.
21.
Immediate losses of coastal and marine resources are estimated at about US$200M.
22.
Long-term losses can be expected to be much higher.
23.
Most of the resources are expected to recover naturally, although the economic loss
period may be several years in some cases.
24.
Investment in recovery effort is recommended only for a few resources, such as beaches
and fisheries.
25.
Recovery of watershed forests should be aided in order to reduce adverse run-off effects
on coastal waters.
26.
The report highlights the need for further study of coastal and marine resource
economics.
27.
Key areas for research on marine resources and impacts of disasters are listed.
28.
The report is supported by 10 appendices containing detailed information on impacts of
Hurricane Gilbert.
29.
The report is the first compilation of data and professional opinions on the effects of
hurricanes on a wide range of coastal and marine resources in Jamaica.
30.
The report is intended as a framework for more detailed analysis of the economic impacts
of Hurricane Gilbert.
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...Hurricane Gilbert...
1. INTRODUCTION
2.1.
Survey of Hurricane Damage
Hurricane Gilbert struck Jamaica on 12th September 1988, causing loss of life
and considerable property damage. The Government and the scientific community acted
quickly to establish several working groups to assess the damage in different sectors of
the economy (Anon, 1988a), and to aid repair and recovery.
Although working groups were convened with responsibility for "Environment
and Conservation" and for "Agriculture " (which presumably included fisheries), the
Regional Co-ordinating Unit of the Caribbean Environment Programme, UNEP, felt that
special attention should be paid to coastal and marine resources, because of their
importance to the economy of this island state. It was decided that the assessment of the
impacts of Hurricane Gilbert on, these resources should be undertaken in two phases: (a)
a rapid survey to assess the scope of damage and identify the types of economic impact
which resulted; and, if further funding were available, this would be followed up by (b) a
longer-term study which would include a comprehensive economic analysis of damage,
repair, recovery and the introduction of measures to reduce future losses.
This report is concerned with the first phase of this economic impact assessment,
and attempts to provide a framework for the more detailed analyses which are to follow.
Furthermore, after critically reviewing the existing information, the report outlines further
research that will be necessary to accurately assess the effect's of Hurricane Gilbert on
coastal and marine resources.
2.2.
Terms of Reference
The Terms of Reference received on 16.11.88 stated that:
"Under the direct supervision of the Regional Co-ordinating Unit of the Caribbean
Environment Programme, the consultant will prepare an ecological assessment in
economic terms of the damage and impact of Hurricane Gilbert on the coastal and marine
resources of Jamaica.
Specifically, he will:
· Make a rapid assessment of the extent to which coastal ecosystems and marine
resources (beaches, coral reefs, fisheries, mangroves and seagrass beds) have
been altered and/or damaged by Hurricane Gilbert.
· Assess the economic implications of these effects with a view to:
- identifying priority areas for recovery effort,
- reducing economic losses in future hurricane events,
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CEP Technical Report No. 4
- identifying key areas for marine resources research and management
effort.
All available information on the effects of the hurricane with respect to coastal
and marine resources will be assembled and collated by the consultant, including
information resulting from interviews with government agencies and statutory bodies.
The consultancy is to be undertaken within one man-month."
2.
METHODOLOGY
2.1.
Resources to be Considered
The major natural resources of coastal and marine environments of Jamaica were
identified by the consultant, in accordance with the Terms of Reference, and are shown in
Table 1.
Table 1.
Resources Considered in this Report
Resource
Types of resource uses and values
1. Beaches
Recreation
&
tourism; shorefront property
2. Coastal Waters
Water quality values (colour, clarity, cleanliness) in tourism
and recreation (shipping, navigation & waste disposal uses not
considered).
3. Coral Reefs
Coastal protection, fisheries, recreation, support for marine life and
productivity (associated flora and fauna included).
4. Seagrass beds
Support to marine life and productivity (associated flora and
fauna included).
5. Mangroves
Coastal protection, productivity, timber, charcoal, shellfish,
support to marine life (associated flora and fauna included).
6. Littoral Woodland Coastal protection, dune and shoreline stability, scenic quality.
7. Fisheries
Food production (scalefish, crabs, shrimp, conch, oysters, lobsters,
turtles).
8. Seabirds
Food production, wildlife, recreation and education.
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...Hurricane Gilbert...
The report deals only superficially with man-made structures used in the
exploitation and management of coastal and marine resources, such as beach and
shoreline defences (groynes, seawalls), fisheries infrastructure (huts, gear stores, boats),
and with buildings or facilities at resorts or recreation areas. The emphasis is placed on
damage to the. primary resources themselves, as required by the Terms of Reference.
2.2.
Data Sources and Data Collection
The information contained in this report comes from the following sources:
· Written submissions: Seven staff of the University of the West Indies, Mona, who
have on-going research projects in different coastal environments were asked to
record relevant observations and field measurements, or information that they had
received. These submissions are reproduced in full as Appendices 1, 2, 4-6, 9 & 10.
· Natural Resources Conservation Department: Reports of surveys conducted by staff
of NRCD, Ministry of Agriculture, and contained in the agency's files were kindly
made available by the Director, Dr. Marcel Anderson. These included field
observations made by A. Bailey, P. Campbell, E. Foster, L. Gardner, J. Miller, O.
Morgan, J. Taylor, and L. Thompson, which are summarized in Appendix 7.
Discussions were held with some of these observers to clarify points made in their
reports. NRCD also has a set of photographs of damage to beaches and coastal
infrastructure, part of which studied by the Consultant. Contacts with staff from other
agencies suggested that there was little information about damage to primary coastal
resources in their files, so these were not consulted.
· Surveys: Wetlands and related coastal areas were surveyed by the Author on 24, 28 &
29 November 8, 9 & 30 December 1988, and on 1 January 1989. Results of these
surveys are summarized in Appendix 3. A photographic record of damage to wetlands
was made on these occasions; some of this is reproduced in the Appendix. The
University of the West Indies Sub-Aqua Club was asked to survey the Marine Park at
Ocho Rios. Due to prevailing poor sea conditions, only one preliminary dive could
be completed in time for this report. Details of this survey, made by R. Robinson; M.
Lindo; K. Roberts and G. Elliot, are given in Appendix 8.
· Personal communications: Miscellaneous comments made to the author by a number
of persons about different aspects of hurricane damage are included in this report. The
author takes responsibility for the accuracy of these communications.
The limitations of the data obtained from these sources are discussed in Section 4.
The time allocation and activity schedule for this project was as follows:
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CEP Technical Report No. 4
Day
Activity
1
Project planning, definition of terms, identification of information sources.
2 4
Compilation of existing information and reports.
5 12
Field surveys (ground & aerial).
13 22
Sub-contracted time for work by co-operating specialists; interviews and
discussions, visits to agencies.
23 25
Analysis of information; review with co-operating specialists.
26 - 30
Preparation of report.
2.3 Ecological
Assessment
There is no generally agreed set of criteria for assessing impacts of hurricanes upon
natural systems; a wide range of terminology has been used in earlier reports on hurricane
damage to coastal and marine ecosystems in the Caribbean region (Craighead & Gilbert,
1962; Alexander, 1968; Lugo & Snedaker, 1974; Zack, 1986).
The reports on file at the Natural Resources Conservation Department do not define
criteria used for assessing damage, or the meaning of terms used, such as "severe" and
"extensive". Furthermore, terminology was not standardized among the specialists making
written submissions that appear as appendices.
Review of these reports, supported by field observations and study of available
literature, suggested adoption of the terms listed in Table 2 for describing sectors of the
coastal environment and the degree of damage:
Hurricane Gilbert, as with previous hurricanes, impacted on natural systems in several
ways, including:
· Winds - abnormally high winds gusting to over 130 m.p.h.
· Waves - increased height and force of sea waves as a result of wind action, plus the
related phenomena of battering and scouring by waterborne sand and debris.
· Storm surge - increased height of standing water level, resulting from changes in
atmospheric pressure, which, coupled with wave action, produced damage at higher
elevations on the shore and further inland.
· Precipitation - increased rainfall, leading to increased run-off with effects on salinity
and sedimentation, plus flooding of low-lying areas.
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...Hurricane Gilbert...
Some data on winds and rainfall during Hurricane Gilbert are shown in Table 3.
The track of Hurricane Gilbert passed directly across Jamaica, so the level of intensity of
these parameters and the location of their impact varied in relation to the geography of the
coastline. Intensity and impact locations also differed from those of Hurricane Allen, which
passed north of the island in 1980, particularly with respect to storm surge.
Table 2.
Terminology Used in this Report
1.
General
terms:
Littoral
-the coastal area under tidal influence
Onshore
-the active shore zone (main part of beaches)
Nearshore/Inshore
-the area between low water level and reefs or barrier islands
Offshore
-the area seaward of reefs or barrier islands
Fastland
-dry
land,
terra fima, above high tide level, including cliffs and
headlands
2. Categories of hurricane damage:
Slight
- < 10%
Moderate -
10-50%
Severe
-> 50%
Severe damage, from the point of view of a population of organisms, can be described using the
terminology of Highsmith et al, 1980, as:
Disastrous
- damage I such that the population can recover
Catastrophic
- damage virtually terminates the existence of the local population,
such that its recovery is possible only if there is recruitment from
outside the damaged area.
The parameters listed above may have acted singly or in concert on different coastal
systems, or parts of systems, over several hours or at one period of peak intensity. The
orientation and aspect of the different bays, headlands and other coastal features can be expected
to have an influence on the severity of the impacts and the various biota in the natural systems
will show differing susceptibility to the range of potential impacts.
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CEP Technical Report No. 4
Table 3.
Some Meteorological Features of Hurricane Gilbert
Parameter Date
Time
Direction
Av.
Max.
(Sept)
speed speed
(kt)
(kt)
Tropical storm force winds
12
0900
32 0
35
62
Hurricane force winds
12
1200
330
65
110
Hurricane eye
12
-
Hurricane force winds
12
1500
-
67
114
Tropical storm force winds
13
0600
3 5
45
Rainfall September 12th 223.4 mm
(Source: Meteorological Service, Norman Manley International Airport, November 1988)
However, while the specific causes and sequence of impacts on coastal and marine resources
during Hurricane Gilbert could not be determined with any accuracy, levels of impact were
determined as the percentage of physical damage (breakage, scouring, erosion, dislocation), and
the nature of biological change (mortality, population decline, alteration of relative dominance of
species).
In very few cases was there any accurate description of the resource components or
resource-supporting natural systems (beaches, mangrove areas) prior to Hurricane Gilbert, so
that precise measurement of the degree or extent of ecological impact was difficult. Furthermore,
time constraints in the Terms of Reference have not allowed even the recognisable damage to be
recorded in the detail which would have been possible with further funding and manpower. The
ecological assessment is largely qualitative, therefore.
Alteration to the ecology of coastal and marine areas of Jamaica was recorded from days
after the hurricane event during a period of only three months. Immediate effects, particularly on
the marine fauna, were not observed, so the data gives evidence only of short-term effects. In
making the assessment, however, an attempt has been made to view the damage and biological
chances from the longer term perspective. As Woodley (Appendix 9) makes clear, hurricanes are
one of the natural forcing, functions of Caribbean coastal ecosystems; so that modification of a
system by an individual hurricane must be viewed against long-term structural development,
successional change, adaptations and population dynamics in order to appreciate the significance
of recorded ecological effects. In making the ecological assessment, possible long-term effects
are noted, particularly the likely direction of ecosystem or population recovery, as are possible
effects of pre-hurricane human impacts on the status of natural systems under stress from the
hurricane.
To aid in the ecological assessment, library search was conducted for papers on the
environmental effects of earlier hurricanes in Jamaica. -Effects on coral reefs were well covered,
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...Hurricane Gilbert...
but there appeared to be very little relevant scientific literature on other ecosystems or resources.
A list of the reports located is given in Appendix 11.
2.4 Economic
Assessment
As indicated in Table 1, a range of resources of direct and indirect value was identified
in coastal and marine environments of Jamaica. An attempt was made to consider the
economic consequences of Hurricane Gilbert with respect to these resources under the
following headings:
· Value of resources lost or damaged
· Loss of income resulting from the value of resources lost or damaged
· Costs of resource substitution
· Costs of resource recovery
· Costs of protecting resources from future events.
In order to make a valid assessment, the value of lost or damaged resources would need
to be calculated for both short-term and long-term scenarios, based on their "capital" value
or economic worth. This would be particularly important where indirect values are
concerned, such as coastal protection from a reef or the fisheries support provided by
mangrove nursery areas.
Loss of income is more directly measured, but should be considered on similar time
scales. Losses may be borne privately, as in the case of hotel beachfront erosion, or publicly
with the loss of a community bathing beach. There are difficulties involved with assessing
loss of income from damage to common property resources, like reef fishing grounds, and in
obtaining data from the artisanal user groups generating income through informal marketing
procedures.
Costs may be involved with resource substitution, if a hotel must provide alternative
facilities to guests because of damage to a beach, or fishermen must obtain alternative gear
to that normally used on a reef which has been damaged. Resource substitution may be only
temporary if natural or artificial recovery is anticipated. Where livelihood is normally
dependent on multiple activities, the substitution process may be easier and costs lower.
The economics of resource recovery must be assessed in terms of the feasibility and
desirability of taking action. Natural systems, including beaches, are likely to recover from
hurricane-induced disturbance, given sufficient time. The costs of a "No-action" strategy
(sustaining continued losses while the system recovers naturally) must be weighed against
the costs of direct action (beach re-nourishment, mangrove re-planting) which may return
the system to productive use more rapidly. Involved are the costs of supporting research and
monitoring activities. Natural recovery might be aided by closing off the area from public
use, such as prohibition of fishing on a damaged reef, but this introduces further socio-
economic considerations.
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CEP Technical Report No. 4
Some of the damage to infrastructure designed to facilitate coastal resource use could
be avoided by appropriate design, set-back or zoning regulations. Costs of redesign or
relocation must be compared to the utility and realised gains from having structures remain
in their pre-Hurricane Gilbert positions. Although of importance economically, damage to
man-made structures was marainal to the Terms of Reference of this study.
Althouah little can be done to protect natural resources from hurricane damage, it is
likely that the susceptibility of some systems, such as beaches, mangrove areas and seagrass
beds, is increased when these areas have been modified previously by human activity. The
costs of managing natural ecosystems in a healthy condition could be acceptable if damage
is correspondingly reduced, in addition to other resulting benefits.
As a first step towards economic analysis of factors such as those discussed above, an
attempt was made to locate relevant information on the value of the individual coastal and
marine resources of Jamaica; the extent of current resource use; the dependence for
employment or income; and the rates or likelihood/indications of natural recovery taking
place. This information was assessed for its accuracy, completeness and availability. A
framework for further, more detailed economic analysis was then prepared.
3. IDENTIFICATION OF IMPACTS
3.1 Beaches
Information on impacts of the hurricane on teaches and associated onshore features is
contained in Appendices 1, 4, 6 and 7; and shows wave and storm surge effects of
varying intensity on different areas of the coast.
Of the 56 beaches surveyed by NRCD (Appendix 7, Fig. A7.1), 57% were found to be
eroded. Sand lost from the beach face was either transported out of the site or, more
frequently, piled up at the back of the beach forming a storm berm. In several cases
(Roxburgh, Pear Tree Bottom), coral debris was deposited on top of the beach sand,
while in others it was spread inland beyond the limits of the beach (Fig. A3.11). The
deposition of plant debris (seagrass blades, seaweed, fragments of littoral vegetation or
driftwood) was reported commonly. The distance to which storm surge had carried sand,
coral or plant debris varied with the degree of exposure of the beach and the topography
of the backbeach areas. As these factors were not recorded along with observations on the
degree of erosion, it is difficult to draw conclusions about the height of storm surge at
any point.
The reports suggests that damage to beaches was most severe at the eastern end of the
island, from Rozelle round to Manchioneal, and along the north-western and north-
central coasts. The south coast suffered less damage. One observer thought that storm
surge reached about 4 ft on the east and parts of the north coast, but only 3 ft. or less on
the south and most of the north coast (J. Lethbridge, personal communication). The
approach of the hurricane from the east over the sea could be expected to localize highest
storm surge effects in the east coast sector, but be less marked as the track continued over
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...Hurricane Gilbert...
land. Dominant wind directions (Table 3) would focus wave and surge effects on the
north and east coasts at different stages of the hurricane's passage, leading to greater
damage in those areas.
Some net movement of beach sediments to westward is suggested by reports of beach
accretion at Burnwood and Club Paradise (Appendix 7), and by the shape of some Post-
hurricane beach profiles examined between Ocho Rios and Wyndham Rose Hall.
By the time of the NRCD surveys (Appendix 7), debris had been cleared from many of
the privately managed hotel beaches. During the following two months, several of the
beaches showed signs that they had begun to prograde and re-establish pre-hurricane
profiles; as at Mammee Bay, St. Ann (Fig. A3.3), and the Trelawny Beach Hotel
(personal communication, unidentified member of staff). Rebuilding of beaches was
aided in some cases by mechanical shifting of the sand that had been piled up on the
backbeach.
It will be difficult to determine the speed with which beach profiles are restored, as the
existing air photo coverage has not been obtained recently enough to determine profiles
immediately preceding Hurricane Gilbert. However, it is apparent that natural re-
nourishment is taking place very rapidly in some areas.
Jones (Appendix 6) gives further information on beach erosion and modification, which
generally confirms the NRCD statements. She has shown also how beach tar pollution
levels on beaches changed as a result of the hurricane. In the majority of cases there was
transport of tar balls to backbeach areas, but some beaches we're swept clean of oil
residues.
3.2
Coastal Water Quality
Coastal water quality is considered broadly, to include alteration to the normal colour and
clarity, changes in salinity and suspended particle content; the latter related to increased
sedimentation in coastal water bodies.
A deterioration in water quality in coastal areas all round Jamaica, due to increased
amounts of suspended particles (sand, organic matter), is likely during and immediately
following Hurricane Gilbert. It appears, however, that clear water conditions were
reestablished quite quickly, as high turbidity was not recorded along the open coast by
any of the contributors to this report in the weeks following the storm. Woodley
(Appendix 9) provides the only detailed information, showing that at Discovery Bay it
took about two weeks for underwater visibility to return to normal.
The NRCD report (Appendix 7) notes increases in silt deposits in rivers following
Hurricane Gilbert, especially in the Morant and Plantain Garden Rivers, and a plume of
turbid water at Rio Bueno. Increased terrestrial run-off, following heavy rains associated
with the hurricane, must have contributed substantially to increases in turbidity and
sedimentation in marine environments near the mouths of major rivers. This is a frequent
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CEP Technical Report No. 4
occurrence after storms at Rio Bueno, Great River and other locations, but its ecological
effects are poorly documented. Damage to watersheds, due to loss of forest cover and
subsequent erosion, may prove to be of great importance to water quality and
sedimentation in coastal environments of the next few years, because of the long-term
nature of recovery of those upland environments.
At the end of November 1988, the Port Authority contracted with the Royal Navy
Hydrographic Survey Ships HMS Beagle and Fawn to survey Kingston Harbour, to see if
storm run-off following the Hurricane had caused silting of the ship channel (Anon, 1988
b). It was feared that any appreciable amount of silting, including tree debris and garbage,
might cause obstructions to shipping. However, sonar traces showed no appreciable
silting since the previous survey conducted in about 1987 (Capt. P. Prawl, personal
communication,). If a high sediment load had been brought to the Harbour from the Rio
Cobre and other drainage channels, it is more likely that it would have been deposited in
Hunt's Bay.
Salinity in Kingston Harbour was reduced after Hurricane Gilbert and remained lower
than normal for several days, as noted by Alleng (Appendix 2).
3.3 Coral
Reefs
The best set of data on the ecological impacts of Hurricane Gilbert comes from the
Discovery Bay Marine Laboratory; as researchers there have long-studied monitoring
stations on the reefs and had documented the effects of the previous hurricane (Hurricane
Allen, 1980).
Woodley (Appendix 9) reports that damage to the reefs in the Discovery Bay area was
severe. The level of damage was lower than that caused by Hurricane Allen, however,
because the reef had not recovered to its pre-Allen structure and complexity by the time
Gilbert struck. The types of damage were similar, and included breakage and smashing of
branching and massive corals, scouring and abrasion by water-borne debris and
redistribution of the debris, plus overthrow and breaking of sea-fans and other reef
organisms. Some degree of disturbance to fish territories and behaviour was noted. The
aeneral effect of Hurricane Gilbert has been to return the reefs to their immediate post-
Allen condition.
The effects of the Hurricane are likely to be felt in a loss of productivity, particularly
fisheries production due to habitat damage. The base structure of the reef has not been
disturbed to the same extent as the cover of living organisms, so structural values, such as
coastal protection, should not be reduced.
As during the period following Hurricane Allen, reef recovery at Discovery Bay was
evident in a few weeks and is expected to continue. Recovery can be expected to be a
long-term process; pre-Allen ecology and productivity level had not been re-established
by the time of Hurricane Gilbert (a period of 8 years). Furthermore, the reefs at
Page 10
...Hurricane Gilbert...
Discovery Bay must recover without any reduction in current fishing pressure or other
stressors.
Other data for north coast reefs comes from a preliminary survey of the marine park at
Ocho Rios. Robinson et al (Appendix 8) report breakage of corals close to the reef crest,
plus the re-distribution of reef debris in the back-reef areas and scouring of algal cover.
Increased quantities of reef rock debris were observed in the back-reef zone at Pear Tree
Bottom and debris from the "Allen Islands" at Discovery Bay (thrown up in 1980) had
been pushed over and re-distributed in the lagoon by Hurricane Gilbert, reducing the
height of these islands.
In addition to this, damage to the reef crest zone was observed at Orange..Bay (Ralph
Robinson, personal communication), and included gouging on the windward side of coral
buttresses, blockage of channels and burial of previously familiar topographic features. In
places it appeared that more than a metre of sand had been deposited over entrances to
channels and a sand bar had appeared in the back reef area, with dark coloured sand of
possible riverine origin.
No data was obtained from the south coast reef areas.
3.4 Seagrass
Beds
Very little information is available on the extent of damage to seagrass beds around
Jamaica.
Aiken (Appendix 1) reports only moderate disturbance of seagrass beds, including
erosion of the edges of pre-existing "blow-outs". The observation of remaining short
stumps of seagrasses in the Discovery Bay area suggest that blade fracture had occurred.
There was some evidence of reductions in fish populations; but these are likely to have
been temporary.
The following observations by the Author support Aiken's conclusions:
(24.11.88) Hellshire:
Quantities of Thalassia debris on Half Moon and Great Salt Pond (east side) Beaches was
not unusually high (compared with Witter, 1983; Bacon & Head, 1985; Head & Hendry,
1986). However, on Salt Pond Beach, several relatively freshly-cast up shells of the
bottom-dwelling bivalve, Atrina seminuda, were found, suaaestina that benthic sediments
had been severely disturbed by hurricane swells.
(29.11.88) Beach adjacent to Wyndham Rose Hall Hotel, St. James:
Slightly increased quantities of seagrass debris on the beach. In two samples examined,
Thalassia blade material was 72% and 68% (wet weight) respectively. This indicated
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CEP Technical Report No. 4
little disturbance to the sub-sediment rhizomes and, thus, only superficial damage to the
seagrass beds.
(08.12.88) Llandovery:
As shown in Figure A3.6., quantities of seagrass debris were thrown among mangrove
prop roots. Quantities appeared to be larger than normal and contained on estimate >80%
blade material. Damaae at this site appears to be confined to the above-ground portions of
the plants also.
Beach debris levels are difficult to interpret at some sites in the absence of previous
quantification, but, coupled with the small amount of visual evidence of erosion in the
beds themselves, it appears that hurricane damage to seagrass ecosystems has not been
serious. Re-growth of blades from undisturbed rhizomes can be expected.
3.5
Mangroves and other Wetlands
Wetlands were studied at 25 sites (Fia. A3.1.). In contrast to the situation in coral reefs,
mangroves were more seriously damaged by Hurricane Gilbert than appears to have been
the case during Hurricane Allen.
Due to the lack of previous damage, some areas contained well developed, mature trees,
such as Crater Lake and Florida Lands on the north coast. Wind damage by Hurricane
Gilbert to these forests was severe, with the loss of a high percentage of the tall trees.
Lugo and Snedaker (1974) suggest that, in the Caribbean islands, mangrove forest
structure and maximum biomass is limited by hurricanes. Mangroves reach maturity in
20-25 years so that, with a hurricane frequency of about 20 years, full maturity is rarely
attained before the forest is damaged. The sizes of red and black mangrove trees in some
north coast sites (see Appendix 3) suggest that these forests had not been exposed to
hurricane force winds for a considerable time period, certainly more than 25 years.
Following Woodley's argument (Appendix 9) it appears that, whereas north coast reefs
had already been damaged by Hurricane Allen when Hurricane Gilbert struck, the
mangrove forests were still in their "pre-Allen state" and damage was correspondingly
greater.
The situation on the south coast is less clear, but several factors may be involved in the
lower levels of damage recorded. Wind forces appear to have been lower; much of the
coastal mangrove is growing under edaphic conditions that do not permit full tree
development; and some pre-Gilbert storm damage is evident.
In some cases, damage to coastal wetland vegetation was due to wave action or
transported debris, but the main damage was caused by the wind. Hurricane and gale
force winds acting over a long period of time caused defoliation, branch and trunk
damage and felling of mangrove trees. Defoliation was the most widespread effect.
Damage was recorded to all genera of mangroves, Rhizol2hora. Avicennia, Laguncularia
and Conocarpus, but was highly variable between sites. The north coast was generally
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...Hurricane Gilbert...
more seriously affected than the south coast, with the exception of the Great Morass in
St. Thomas at the southeastern tip of the island. A gradient in level of damage was found
along the south coast, with areas west of Kingston successively less affected. On the
north coast, no such gradient was detectable.
As mentioned, the best developed mangrove forests on the north coast suffered the
greatest damage (Fig. A3.7, 11 & 12). Tall red mangrove (Rhizophora) suffered
defoliation (Fig. A3.10) or toppled after breaking above the buttress roots (Fig. A3.8),
while mature black mangrove (Avicennia) was uprooted at several sites (Fig A3.13).
There was loss of up to 60% of the trees in some forest stands, although such damage was
patchy, and defoliation/branch breakage between 75 and 100% in other stands, such as
the Great Morass in St. Thomas and Florida Lands, Trelawny. Defoliation tended to be of
the upper parts of the canopy and lower strata appeared virtually unchanged in most
mangrove areas. Furthermore, very few Rhizophora were found uprooted in any of the
north or south coast swamps examined; so, although the arboreal environments were
damaged, prop roots and their associated biota remained in tact.
Other fauna associated with mangrove areas did not appear to be reduced following the
hurricane; waterbird populations at several north coast sites, where records had been kept
over the last few years, showed no obvious sign of depletion. Even where regular
roosting areas had been severely damaged, as at Florida Lands (Fig. A3.12 & 13),
pelicans and herons still used the damaged trees. Cattle egrets similarly continued their
use of a damaged mangrove tree roost at Pear Tree Bottom (Fig. A3.8).
Although severe, damage does not appear to have been catastrophic in any of the
mangrove areas examined. There may be some delayed mortality in defoliated trees,
although most are expected to recover. Even where a high percentage of the larger trees
have been lost, younger trees and saplings are present and the ecosystems can be
expected to recover. Red mangrove stands studied at Crater Lake and Falmouth showed
dense seedling cover; and growth of these is likely to be enhanced by thinning of the leaf
canopy. Although the damaged black mangrove stand at Saltmarsh (Fig. A3.15) had
minimal numbers of seedlings, there were abundant saplings and some regrowth from
coppiced adult trees. Species composition in the Crater Lake forest may change during
regrowth, as there is a preponderance of white mangrove seedlings on the floor of what
was previously a red mangrove-dominated forest, and it is possible that some black
mangrove areas will not be able to recover fully if drying out of the swamps takes place
due to loss of tree cover. Otherwise, recovery is likely in mangrove forests throughout the
island.
It should be noted that, in several areas of the coast where human impacts had been
severe before Hurricane Gilbert, interpretation of the relative importance of human and
hurricane-induced damage was difficult. This was particularly true for Hellshire
(Fig.A3.2) and Half Moon Bay, Falmouth, where charcoal burning had been in progress
at least since 1987.
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CEP Technical Report No. 4
3.6
Littoral Woodland and Strand Vegetation
Littoral woodland forms a fringe of trees and shrubs in back beach and shore
environments; it includes such species as the button mangrove, Conocarpus, erectus (see
section 3.5), seaside grape, Coccoloba uvifera, seaside mahoe, Thespesia populnae, and
West Indian almond, Terminalia catappa. The community of herbs and shrubs that
spreads seawards across dunes and beaches is referred to as the strand vegetation; it
includes such species as the beach morning glory, Ipomoea pes-caprae brasiliensis,
seaside bean, Canavalia maritima, and the grass Sporobolus virginicus.
Scattered records of damage to shore vegetation are given by Bacon (Appendix 3) and the
NRCD (Appendix 7). These range from erosion at the roots or branch fracture in seaside
trees, as at Couples Hotel and Ocho Rios, and extensive uprooting, as at Eden II and Pear
Tree Bottom (Fig. A3.7), to complete destruction of the littoral fringe trees, as at Priory
and Bengal-Queen's Highway. There was some damage along almost the whole of the
island's eastern and northern coastline.
Although no specific information was obtained, wherever beach erosion was recorded it
is likely that some of the strand vegetation was lost or damaged. Recovery of this
vegetation will be important in sand restabilisation at the upper level of beaches.
3.7 Fishery
Resources
Damage to the fishery resources is discussed at length by Aiken (Appendix 1). Fishermen
and the Government Fisheries Division suffered heavy losses in terms of equipment
(boats, fish pots) and infrastructure (buildings, shellfish culture rafts, artificial reefs).
However, the nature and extent of damage to the primary resources (scalefish, lobster,
conch, etc.) was less conspicuous. Aiken (Appendix 1) and Woodley (Appendix 9)
describe perturbation of coral reef environments, and include some qualitative
observations of the effects of the hurricane on fish populations. Whether significant
reduction in reef fish population size or alteration in species composition took place, how
long these effects will last, what recovery in fish populations can be expected, and how
soon, cannot be stated with any accuracy. Unfortunately, baseline data against which to
assess changes does not exist with the necessary degree of detail (as it does for coral reefs
at Discovery Bay - Woodley, Appendix 9).
Furthermore, no study appears to have been carried out on the effects of Hurricane Allen
on coral reef fishery resources, or of the pattern of post-Allen recovery. This might have
given an indication of what the long-term effects of Hurricane Gilbert are likely to be on
this sector of the economy.
It is surmised that there was little direct mortality to fish, crustaceans or mollusks as a
result of Hurricane Gilbert; but that the resources may decline as a result of damage to
feeding and breeding habitats, particularly on the coral reefs. Damage to seagrass beds
does not appear to have been serious, and aquatic habitats of mangrove areas appear to
have been less affected than arboreal (trunk and canopy) habitats. Prop root habitats in
Page 14
...Hurricane Gilbert...
red mangrove areas, which are important for feeding and as juvenile fish habitat, were
little disrupted by the storm. Furthermore, flat tree-oyster populations at Saltmarsh and
natural populations of mangrove cup-oysters near the Bowden oyster culture site show no
signs of mortality or dislodgement as .a result of the hurricane.
Although Aiken (Appendix 1) notes that the hurricane occurred during the nesting season
for sea turtles, it struck well after the normal peak nesting time (Bacon, et al, 1984), so
direct damage to eggs and hatchlings is unlikely. What may be of significance is the
degree of recovery from erosion of beaches that might be required for next season's sea
turtle nesting.
Although the losses of gear and earnings by fishermen are to be regretted, long-term
effects of Hurricane Gilbert on coastal fish and invertebrate habitat may be the most
important issue facing the fishing industry. The lack of data is unfortunate.
3.8
Seabirds and Shorebirds
About 40 species of water birds (terns, pelicans, herons, plovers, sandpipers, ducks, etc.)
feed, roost or nest in coastal habitats around Jamaica, including the offshore cays. The
majority of these are resident but others occur seasonally during migratory passage
through Jamaica; and populations of resident species may be supplemented by passage
migrants. Although there is considerable information on the status of seabirds and
shorebirds (i.e. how common they are, whether they nest), less is known about their
degree of dependence on particular locations for feeding or breeding. Consequently, it is
difficult to relate hurricane damage at a particular site to expected disturbance of the bird
populations. Furthermore, wading birds, such as herons and egrets, regularly move
between feeding habitats to accommodate to fluctuating water levels and food availability
(diurnal, tidal and seasonal changes); so that hurricane damage to one part of their habitat
will more likely lead to greater use of another part, rather than population disruption.
Where regularly used roosting or nesting sites have been damaged, effects on present and
future populations might be expected, but only if alternative sites are unavailable.
Haynes-Sutton (1988) predicted that Hurricane Gilbert had caused severe damage to bird
populations in Jamaica, although providing no evidence that this was so. She was
particularly concerned with loss of endemic species as a result of damage to terrestrial
forests. No endemic seabirds or shorebirds are found in Jamaica, so that aspect of the
potential problem is not relevant to coastal and marine resources. Clark (1988) reported
the destruction of some waterbirds in Mexico as a direct result of Hurricane Gilbert, but
no reports have been received of adult bird mortality in Jamaica.
The only evidence of direct damage is a report that a nesting/roosting area on Refuge
Cay, in Kingston Harbour, was severely damaged when pelicans were in process of
nesting. Some loss of eggs and young birds took place. However, the pelican colony
moved approximately 150m westward to another mangrove stand at Gallows Point and,
three weeks later, were sitting on new egg clutches (I. Goodbody, personal
communication).
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CEP Technical Report No. 4
Loss of eggs or young at the economically important tern nesting sites on the Morant
Cays is not expected as the hurricane struck outside the main nestinc, period (mid-April
to June; Haynes, 1986). The level of damage to nesting habitat on the Cays is not known,
as reports of wave or storm surge levels there are not available.
Hurricane Gilbert also struck prior to the main autumn passage period of migrant birds.
Some damage to roosting sites was also recorded (Appendix 3). At Pear Tree Bottom, an
egret and heron colony was not displaced by severe damage to roost trees (Fig. A3.8), but
simply adjusted to use of the remaining mangroves. Pelicans, herons, egrets and other
birds around Falmouth showed roost site fixation, despite considerable damage in that
area.
Miscellaneous observations suggest that seabirds and shorebirds have been little affected
by the hurricane. Waterfowl counts by the author in wetlands at Hellshire, Florida Lands,
Salt-marsh and Wyndham Rose Hall showed no significant change from pre-hurricane
levels. In the last site, where vegetation was damaged and seawater introduced into the
swamp (Greenaway, Appendix 5), grebes, moorhens, ducks and waders were present in
expected numbers a few weeks after Gilbert.
Apart from damage to beaches, which ma have caused some disturbance to feeding by
shorebirds such as plovers and sandpipers, feeding habitats of waterbirds appear to have
been little altered by Hurricane Gilbert. In mangrove areas, damage at ground level
appears to have been much less than to upper tree levels. Accumulation of litter and
debris and some flooding of low lying areas may temporarily restrict feeding at those
sites, but the effect on waterbird populations is likely to be minor.
4. FRAMEWORK FOR ECONOMIC ASSESSMENT OF THE IMPACTS
Preamble: It must be stated clearly that a meaningful economic assessment of the impacts
of Hurricane Gilbert on coastal and marine resources in Jamaica cannot be made from the
existing data.
Apart from the time constraints placed on this study by the Terms of Reference, the pre-
hurricane economic status of the resources was quantified only for some aspects of the fisheries;
the ecological database was such that the scale of impact could be identified only in a few cases;
very little natural resource economics research has been done in Jamaica; and no coastal or
marine resource economist was working in Jamaica to determine the significance of the changes
which had taken place.
Nonetheless, because of the importance of these resources to the economy of Jamaica, an
attempt is made to provide a framework within which an economic analysis can take place.
Previously available data is reviewed and the limitations of the collected data discussed. Despite
a long history of coastal and marine research at the University of the West Indies and other
Page 16
...Hurricane Gilbert...
institutions, the inventory and assessment of beaches, reefs, mangroves, etc., in terms of their
resource value to the nation, are in their infancy. Until steps are taken to address these aspects of
resource management, the full impacts of hurricanes and other "disasters" will not be properly
understood.
4.1 Economic Worth (Market & Non-market) of the Resources
4.1.1. Beaches
Although the Jamaica Country Environmental Profile (GOJ, 1987) notes the importance of
beaches to the tourism sector, no attempt is made to quantify their value. No estimate of the
value of the total national
beach resource appears to be available.
As one of the primary resources of the tourism sector, the value of beaches could be
estimated in relation to the value of that sector, as follows:
Gross foreign exchange earnings in the tourism sector were US$595M in 1987 (PIJ, 19$8)
and US$530M in 1988 (Green, 1989). The tourism sector is supported primarily by three
environmental resources - sand, sun and sea. Therefore, a value that could be placed on the
beaches is one third of the value of sector earnings; that is approximately US$200M.
An alternative approach would be to examine property values for coastal real estate. Morris
(1989) gives beachfront property values at Negril of J$1.4M per acre. With a linear beach
front length (per acre) of 69.6 yds and a total beach length of 7 miles, the value of Negril
Beach could be estimated at J$247M, or J$35M per mile. (This converts to approximately
US$6.5M per mile of beach).
The above estimate probably gives an inflated value if applied island-wide, as Negril is a
tourism development pole. Nonetheless it does suggest the possible order of magnitude for
resource value.
In addition to tourism, beaches are important as public recreation areas, although there is
very little data on the extent of use. Unpublished records for Half Moon Bay, Hellshire, on
one public holiday in 1986, show about 15,000 people using the beach. Numbers at other
sites may be similar. In the few cases where privately owned beaches are used by the
public, ticket sales could be used to calculate what people are prepared to spend annually
for use of beaches. An example would be the very popular Puerto Seco Beach, Discovery
Bay, which Kaiser Bauxite maintains for the benefit of the public.
Further to this, several "fishing beaches" are important for boat mooring and fish
marketing, while some support resident fishing communities. These beaches, thus, make an
additional indirect contribution to the economy.
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CEP Technical Report No. 4
4.1.2. Coastal Water Quality
Calculation of the economic worth of high quality sea water around Jamaica could be based
on benefits to the tourism sector, as above. Possible decline in fisheries, reef and sea-grass
production, due to reduction in that quality (by increases in turbidity, etc.) should be
quantifiable; although several other variables would need to be taken into account. The
dependence of coral reefs, and to a lesser extent seagrass beds, on clear, silt-free, saline
water is well established in the literature.
4.1.3. Coral Reefs
Unlike the fastland zone, real estate values do not exist for coastal ecosystems, so analysis
of economic worth must be based on a different set of criteria.
As coral reefs protect beaches and are one of the major sources of beach sand particles,
their value must be at least as great as that of the beaches. Added to this is their direct value
for recreational diving and other forms of visitor use; although no separate calculation was
available for this facet of the tourist industry.
Aiken (Appendix 1) states that the major part of fishing activity takes place on or near coral
reefs. The reefs support most of the 12,000 registered fishermen and the 38,000 associated
vendors, and support a harvest of approximately 7,000 tonnes annum-1. As a primary
resource for the fishing industry, a value could be assigned to reefs in accordance with the
industry's contribution to the economy.
In addition, reefs are sources for minor products, such as black coral, shells and coral rock
specimens used in the jewelry and souvenir trades. No figures were available on this trade
(much of which is illegal).
The total economic worth of Jamaica's reefs in probably in excess of US$500M yr-1, when
all these factors, plus coast protection and wildlife support, are taken into account.
4.1.4. Seagrass beds
No
data.
4.1.5. Mangroves (and other wetlands)
No estimate is available for the value of mangrove ecosystems in Jamaica. The exact
hectarage is not quantified, but is approximately 5,500 ha in scattered stands along 10-15%
of the coast.
Browder (1976) estimated a value for mangrove areas in Florida equivalent to US$13,000
ha-1 yr-1. If this figure is accepted as a guide, the value of the national mangrove resource is
in the order of US$71.5M yr.
Page 18
...Hurricane Gilbert...
Mangrove ecosystem values lie in their role in coastal protection, fisheries support, support
of other aquatic and terrestrial biota, production of directly marketable products such as
timber, charcoal, crabs and shellfish, plus actual and potential tourism, recreational and
educational uses.
Mangroves at Bowden, and possibly other sites, indirectly support a commercially viable
oyster culture industry.
4.1.6. Littoral Woodland and Strand
Littoral woodlands and strand vegetation have largely unrecognised scenic and coastal
stabilisation properties, related to real estate values, tourism and recreation. They make a
minor contribution to organic matter production in coastal environments and provide
wildlife habitat. No estimates of these indirect contributions to the economy are available.
4.1.7. Fishery Resources
Fishery resource values are well documented and data is available on harvest sizes and
rates, direct and indirect employment in the industry and market prices. Some economic
aspects of the fishing industry are reviewed by Aiken (Appendix 1), and have been referred
to above (section 4.1.3).
4.1.8. Seabirds and Shorebirds
Direct utilization of seabirds and shorebirds is largely in the form of egg collecting Haynes
(1986) reports that over 600,000 eggs were collected annually from the Pedro and Morant
Cays in the 1920's. Numbers had declined to about 100,000 by 1975 and harvesting
continues at the present time; although no market values are suggested.
Indirect value of birds and other wildlife in recreation and education is not quantified, but
is thought to be minimal at the present time.
4.2 Estimation of Economic Losses Resulting from Hurricane Gilbert
4.2.1. Beaches and -Water Quality
Based on a possible value to the tourism sector of US$200M per year, or US$16M per
month, total loss of beach use for three months following Hurricane Gilbert could be set at
US$48M.
However, NRCD (Appendix 7) recorded damage to only about 57% of the beaches studied;
although this was not necessarily severe enough to halt beach utilization completely.
Losses of earnings as a direct result of erosion and accumulation of debris were probably
small.
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CEP Technical Report No. 4
The scale of tourist cancellations due directly to loss of beach use following Hurricane
Gilbert is not known; nor are the costs to hoteliers resulting from provision of alternative
activities for their guests. It is noted, however, that in most cases recreational beaches were
cleared of debris and made usable within a few days of the hurricane. This involved some
cost, of course.
Reduced amounts of bathing and water sports as a result of poor water quality, possibly
followed a similar trend. Water clarity was re-established relatively rapidly after Hurricane
Gilbert (see Woodley, Appendix 9).
Jamaica Tourist Board data (Green, 1989) suggest that there was a 19% drop in visitor
arrivals "resulting from Hurricane Gilbert" in the last four months of 1988 compared with
the period September to December 1987. Loss of earnings from the 79,000 fewer visitors
can be calculated from Green's article as approximately USS33M.
Losses of beach extent and sand supply are expected to be short-lived in most cases. Beach
quality should recover in most areas, as it has done already in some locations. The NRCD
report (Appendix 7) describes some sites showing net accretion of sand, including the "re-
appearance" of a beach that had been eroded on a previous occasion.
NRCD, 1988 & Appendix 7 reports the costs of repair to damaged beach facilities and
infrastructure, and associated damage in the coastal zone, at between J$40-50M.
4.2.2. Coral Reefs and Seagrass Beds
Disastrous hurricane damage was apparently confined to the east and north coast reefs (no
data available for the south coast). Damage was not uniform and loss of functional values
was not total. That is, losses were apparent in reef fisheries, biological support and possibly
the attractiveness of reefs to recreational divers, but not to their physical structure in
relation to coastal protection or beach nourishment. The end result of the direct action of
Hurricane Gilbert is comparable with that of Hurricane Allen (Woodley, et al, 1981 and
Appendix 9).
The resource value of Jamaica's reefs has probably been reduced by less than half, but only
in some areas of the coast and only in certain reef zones at each damaged location. Based
on a possible resource value of about US$500M per annum, losses due to hurricane damage
on reefs were probably less than US$100M.
If, as Woodley (Appendix 9) points out, hurricane effects are a normal aspect of reef
ecology in Jamaica, the "damage" should perhaps not be considered as a "loss". As
successional recovery processes take place with the re-setting of the "reef clock", there is
the probability of much higher biological productivity than would be found on a mature,
stable reef. From the economic point of view, damage must be considered in the short term;
direct loss from lowered fish yields and reduced recreational use are the only quantifiable
parameters, if data becomes available.
Page 20
...Hurricane Gilbert...
The extent of damage to the Ocho Rios Marine Park could not be assessed fully, and the
Montego Bay Marine Park was not investigated, but damage was probably not severe
enough for tour guides to be prevented from using these parks.
There is no data to use for estimating economic losses from the moderate amount of
damage recorded in seagrass beds.
4.2.3. Mangroves and other Coastal Vegetation
Direct losses of mangrove timber, as at Crater Lake and Falmouth (Appendix 3) are
quantifiable on a site by site basis. Very little mangrove timber is actually harvested, except
for small stakes at the subsistence level, so no market price is available.
In most cases fallen timber has not been lost entirely, as it could still be harvested and used
for charcoal production. From this point of view, resource availability has increased
temporarily, even though the standing crop of future charcoal trees has been reduced. The
econornics of the mangrove charcoal industry in Jamaica are incompletely documented,
however.
From estimates of economic worth of mangroves of approximately US$70M yr-1 and
probable damage levels to mangrove stocks of 20 % island wide, total losses in resource
value may be between US$10-15M.
As with reef, damage was not catastrophic for any of the mangrove stands, and recovery
can be expected. Field observations suggest that re-growth of mangrove forests is taking
place rapidly. Resource recovery and re-establishment of functional values can be expected
in most areas. However, where seedling supply is sparse, as in the Avicennia stands at
Saltmarsh, or mature forest was damaged, as a Crater Lake, the wetland may develop
differently during the recovery process.
Aquatic habitats in mangrove environments do not appear to have been damaged to any
degree, so losses in terms of fisheries and wildlife have probably been minor.
Some damage has been recorded in wetland parks which might have more direct
commercial implications. Repairs to the Royal Palm Park in Negril are being effected at
some cost to the Petroleum Corporation of Jamaica. The proposed Hellshire Recreational
Park has been damaged severely and this may have implications for future development of
recreational and educational use. Damage to the Canoe Valley wetland park area consisted
largely in fallen trees, the cost of removal of which was estimated by NRCD (1988) at
J$5,000.
4.2.4. Fishery Resources
The Ministry of Agriculture has estimated total island wide losses to the fishing industry at
approximately J$25M (including fishing beach, trap, boat and infrastructure losses).
Fishermen probably were prevented from fishing for up to 10 days after Hurricane Gilbert,
with corresponding loss of earnings to themselves and associated vendors. Aiken
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CEP Technical Report No. 4
(Appendix 1) reports that levels of fishing were still depressed two months after the
hurricane.
Losses, immediately and in the future, through damage to fishery habitat and/or juvenile
stocks cannot be assessed with the current data.
4.2.5. Seabirds and Shorebirds
There is no evidence of losses resulting from the Hurricane, in terms of exploitable bird
resources or recreational/educational use of birds or other wildlife. Some habitat damage is
recorded or likely, but its effects cannot be quantified at present.
4.3 Economics of Resource Recovery and Damage Prevention
As indicated above, most resources or parts of resources that have been damaged in coastal
and marine environments in Jamaica are expected to recover naturally. Apart from there
being little that can be done to aid this recovery process, the no-action strategy appears to
make economic sense in most cases.
Intensively used and privately owned beaches have been cleared of debris and, in some
cases, washed up sand has been replaced by mechanical means. In the absence of detailed
documentation on coastal sand dynamics around Jamaica it is virtually impossible to
suggest engineering options that might speed natural beach recovery processes.
The re-planting of coastal vegetation, particularly on dunes, may aid sand stabilisation; but
investment in this should not be contemplated until the speed of natural re-growth has been
studied at critical sites.
In several areas, sand which had been piled upat the back of beaches by the hurricane was
removed for construction purposes. It has been suggested (M. Hendry, personal
communication) that such "sand stealing" delays the process of beach recovery. If this is
so, it should be prevented in order to retain the sand supply for post-storm recovery. In
order to stop people removing this readily accessible source of sand, alternative sources
need to be identified and made available to the construction industry.
Set-back of buildings and other infrastructure behind beaches is recommended as a means
of reducing damage from storms (as well as removing stress from the beach face), but will
not aid in prevention of damage to the beaches themselves. Design of beach developments
should acknowledge the dynamic nature of beaches and the probability of erosion and other
types of storm damage. Aiding the natural recovery of damaged reefs does not seem to be a
feasible option. There is no evidence that reducing the fishing pressure on damaged reefs
would aid their recovery, but this should be investigated. Prevention of future damage is
almost certainly unrealistic.
The Natural Resources Conservation Department (NRCD, 1988) recommend investment in
a programme of seagrass re-planting as an aid to hurricane recovery. Although this may be
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...Hurricane Gilbert...
valuable, it should be preceded by a detailed investigation of the current status of the
seagrass beds in different areas of the coast, and a re-assessment of earlier seagrass re-
planting schemes. Some of the more severely damaged mangrove stands should be
monitored for the degree of recovery, and the need for a re-planting scheme assessed. Like
the proposed seagrass re-planting, this could be very costly and require a large amount of
manpower.
It is thought that little can be done to prevent damage by future hurricanes to either
sea-grass beds or wetlands. It is suggested that, had the mangrove timber crop at sites like
Crater Lake and Florida Lands been harvested as soon as the trees were large enough to be
usable, damage and timber losses could have been avoided.
The littoral woodland vegetation is likely to recover from damage very slowly if at all, as
the plants have to grow under poor edaphic conditions. Re-planting may be advantageous
in many areas of the coast to provide wind-break and scenic attraction. The production of
seedlings and planting costs should be estimated.
With the fishing industry, there is little evidence of primary resource damage, so recovery
is not a problem. The major costs will be involved with repair and rebuilding of supporting
infrastructure. It is noted that national contingency plans for hurricane disaster did not
include gear replacement for fishermen, so fishing was disrupted for an unacceptable
period of time. The economics of such a facility should be investigated, in the light of the
considerable losses sustained by the industry.
Economic assessment of an assisted recovery process must anticipate the expected level
and speed of natural recovery. Some further expenditure on baseline ecological research
would be worthwhile.
5. DISCUSSION
5.1 Utility of the Assessment
In seeking to make an assessment of the economic impacts of Hurricane Gilbert, two major
problems have been identified: (a) the absence of a detailed inventory of the country's
coastal and marine resources, and (b) the shortage of information on the value and current
utilization of these resources. The types of resource damage have been described and the
sectors of the economy experiencing losses identified, but there is an obvious problem
evaluating the losses in the absence of detailed biological information on the extent of
stock damage and potential recovery.
The expected variations in the pattern of resource recovery introduced the further difficulty
of assigning a loss period for economic assessment. Losses of satisfaction to tourists and
residents from beach erosion were considered for a three to four month period, due to the
apparent rapid recovery of the resource. Resource costs to the fishery could be assessed for
a similar period, by comparing expected catch with actual catch in the months following
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CEP Technical Report No. 4
the hurricane; but, if coral reef habitats are going to take more than eight years to recover,
the loss period may need to be greatly extended.
With the exception of hotel beaches and other resources in the tourism sector for which
official data on hurricane costs are beginning to emerge, the major part of the coastal and
marine resources under consideration is utilized directly or indirectly at the subsistence
level. This is a further reason why market data are sparse and difficult to obtain. This
suggests, with the exception noted above, that the costs of hurricane damage were greater
in the subsistence section of the economy.
By identifying gaps in the database, both for the resources and resource utilization, the
study provides a framework for further research and analysis. Although unable to provide
satisfactory hard data, it suggests also what the long-term effects of the hurricane might be
and, thus, identifies priority areas for aiding recovery. These suggestions are listed below:
5.2 Priority Areas for Recovery Effort
Natural recovery is expected in almost all areas of the natural environment subjected to
hurricane impact, but the likely long-term nature of the recovery must be recognised. With
some systems, like coral reefs, the desirability and feasibility of aiding recovery are
questionable, particularly when the scale of the damage and the lack of suitable techniques
are considered. In others, such as mangroves where replanting techniques are well
researched, investment in recovery may not be justifiable until more is known about the
level of economic dependence on mangrove resources. Priority areas for recovery effort
should be those where (a) further natural resource loss or (b) secondary negative
environmental impacts may occur if action is not taken. Until further study of the effects of
Hurricane Gilbert has been carried out, the following areas are identified:
(i) Watershed Management
Evidence presented by NRCD (Appendix 7) suggests increased freshwater run-off and
sediment loading as a result of hurricane damage to upland forested areas. Replanting of
damaged forest and prevention of soil erosion is required urgently to guard against
deterioration of inshore water quality, and the negative ecological and aesthetic effects of
this on the coast.
(ii) Repair to Fisheries Infrastructure and Coastal Defenses
As identified by Aiken (Appendix 1) and NRCD (Appendix 7), damage to beaches and
fishing equipment has caused identifiable losses to an important sector of the economy; and
the effort needed for recovery of the industry can be quantified. Secondly, there is need for
repair of coastal defenses, in order that roads, coastal property and facilities can be used
again.
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...Hurricane Gilbert...
(iii) Repair to Public Beaches
Repair to private beaches and other facilities in the tourism sector is well underway and
that sector is likely to receive attention because of its direct importance to the economy.
There is a danger that beaches used by residents will not be given the attention merited by
their heavy use and t
hat further deterioration may result.
(iv) Replanting of Littoral Woodland
Littoral woodland almost certainly requires replanting, as its natural recovery rate is likely
to be slow. The aesthetic, wind screening and sand stabilising properties of this vegetation
make replanting an economic proposition. Seafront property owners could be encouraged
to replant, but some public effort will be required in selected shoreline areas.
5.3 Key Areas for Marine Resources Research and Management Effort
The areas for research and management effort all relate to the effects of the hurricane;
particularly for improving the data base on resources, their use and levels of damage, but
also for a better understanding of the long-term effects of disasters on coastal and marine
resources. An order of priority is suggested.
(i) The preparation of an accurate, detailed inventory of the coastal and marine
resources of Jamaica (beaches, mangroves, seagrasses, coral reefs, seabirds, etc.).
(ii) An in-depth study of resource economics, to include: available stocks, types and
quantification of resource use, dependence for employment directly and indirectly,
markets, etc.
(iii)
Monitoring
run-off and sediment loads from all major rivers and analysing the
effects on coastal ecosystems. This should be supported by development of a strategy
for watershed management, with an emphasis on protecting the marine environment.
(iv) A study of the rate of recovery of the artisanal fishery in locations where gear and
infrastructure were damaged. This has as its objective the production of a
contingency/recovery plan for the fishing industry for use in future disasters.
(v) A study of the re-establishment of commercial fish populations on selected coral reef
fishing grounds, where damage is recorded.
(vi) Comparison of long-term beach profiles (from air photos) with present profiles, in an
attempt to monitor the rate and direction of recovery.
(vii) A detailed study of the island sand budget (patterns of supply, long-shore drift,
storage and loss); in order to understand the beach erosion and recovery process and
to identify sources of sand which might be available to the construction industry. The
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CEP Technical Report No. 4
latter as an aid to control of illegal sand removal, which might be important to beach
recovery.
(viii) Study of regeneration rates and extent in different mangrove communities. This will
aid in accurate estimation of eventual damage/losses from hurricane damage, but also
identify locations where aided recovery may be required.
(ix) An investigation of the mangrove charcoal economy; with a view to management
(ensuring adequate stocks, controlling recovery of hurricane damaged or cut over
plots to ensure regeneration of the most suitable species, etc.).
(x)
Investigation
of
seabird nesting habitat on the Morant and Pedro Cays to see if aided
recovery from hurricane damage is required. This study to support on-going research
on techniques for the regulation of egg harvesting.
6. ACKNOWLEDGEMENTS
The opportunity provided by the Regional Co-ordinating Unit of UNEP'S Caribbean
Environment Programme to conduct this study is greatly appreciated.
Dr. Marcel Anderson and the staff of the Natural Resources Conservation Department,
Ministry of Agriculture, are thanked for their co-operation, as are the contributors whose names
appear on the appendices to this report. Wings Jamaica Ltd. provided very professional services
for air survey of hurricane damaged coastal areas.
The following persons are thanked for info,7mation and suggestions: Professor Ivan
Goodbody, University of the West Indies; Dr. Malcolm Hendry, University of the West Indies;
John Lethbridge, World Bank, Washington; Captain Patrick Prawl, Port Authority, Kingston;
and Mr. Peter Reeson, Petroleum Corporation of Jamaica.
Mrs. Tyra Bacon is thanked for helpful comments on the economic assessment.
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...Hurricane Gilbert...
7. REFERENCES
ANON 1988 a. Scientists to study and report on Hurricane Gilbert damage. Jamaica Record,
7.11.88; p. 3A.
ANON 1988 b. Royal Navy tests Harbour's depth. Daily G,leaner, 29:11.88; p. 33.
Alexander, T.R. 1968. Effect of Hurricane Betsy on the southeastern Everglades. Quarterly J.
Florida Academy of Sciences, 30 (1); 10 - 24.
Browder, J.A. 1976. An estimate of the value of manaroves to the economy based on net
primary productivity. Unpublished report, National Marine Fisheries Service, Miami; 3 pages.
Craighead, F.C. & Gilbert, V.C. 1962. The effects of Hurricane Donna on the vegetation of
southern Florida. Quarterly J. Florida Academy of Sciences, 25 (1); 1 -28.
Bacon, P.R., Berry, F.D., et al., 1984. Proceedings of the Western Atlantic Turtle Symposium,
San Jose, Costa Rica, July 1983; ) vols, 1138 pages.
_3
Bacon, P. & Head, S. 1985. Formation of a Caribbean Coastal Management Unit. Coastzone
'85, 1; 280-299.
Clark, J 1988. Hurricane Gilbert Assails Caribbe an. ICBP Pan American Bulletin, 3 (2); 2.
G.O.J. 1987. Jamaica Country Environmental Profile. Government of Jamaica, Ministry of
Agriculture, Natural Resources Conservation Division, and Ralph M. Field Ass. Inc., on behalf
of International Institute for Environment and Development; 362 pages.
Green, A. 1989. Tourist arrivals fell two per cent in 1988. Financial Gleaner, 27.01.89; p. I &
13.
Haynes, A.M. 1986. Preliminary report on status and conservation of booby terns at Morant
Cays, Jamaica, 1982 - 1985. Natural Resources Conservation Department; 19 pages.
Haynes-Sutton, A. 1988. Hurricane Gilbert strikes Jamaica's unique birdlife. World Birdwatch,
10 (3-4); 1 & 11.
Highsmith, R.C., Riggs, A.C. & DAntonio, C.M. 1980. Survival of hurricane-generated coral
fragments and a disturbance model of reef calcification/growth rates. Oecologia (Berlin), 46;
322-329.
Lugo, A.E. & Snedaker, S.C. 1974. The ecology of mangroves. Annual Review of Ecology and
Systematics; 39-64.
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CEP Technical Report No. 4
Meteorological Service 1988. Letter to G. Alleng, University of the West Indies, dated
09.11.88, from the Meteorological Service, Norman Manley International Airport, plus
attachments; 3 pages.
Morris, M. 1989. Can Negril be saved from destruction through greed? Sunday Gleaner,
15.01.89; p. 11.
P.I.J. 1988. Economic and Social Survey; Jamaica 1987. Planning Institute of Jamaica; 1-24.7.
Woodley, J.D. et al., 1981. Hurricane Allen's impact on Jamaican coral reefs. Science, 214; 749-
755.
Zack, A. 1986. Hydrology of wetlands in the West Indies. Draft paper to the Caribbean Island
Wetlands Workshop, October 28 - 29, 1986, Rio Piedras, Puerto Rico.
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...Hurricane Gilbert...
APPENDICES
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CEP Technical Report No. 4
Appendix 1
HURRICANE GILBERT AND ITS EFFECT ON FISHERY RESOURCES
By: Karl A. Aiken
Department of Zoology,
University of the West Indies, Jamaica.
General
The fishery resources of Jamaica have been considerably affected by the passage of one of
the most powerful hurricanes in this century, Hurricane Gilbert. To best appreciate the effects of
this hurricane on fishery resources, it is perhaps useful to examine briefly where fishing activity
takes place and the organisation of the fishery.
Approximately 12,000 fishermen, who are full-time registered commercial fishermen,
harvest reef fish, pelagic fish, lobsters and conch resources from the island shelf, principally
along, the edges where coral reef development is greatest. Principal fishing gears used are fish
traps, called Z-type Antillean traps, which have a long history in the fishery. These traps take
approximately 45% of all landings and the remainder of the catch derives from hook and line,
gill and seine nets and spearing.
The traps are set from some 4,000 canoes which operate out on the island shelf. Traps are
set singly, on or near coral aggregations, generally in waters ranging from -25 to -50 m depth.
The distances from the mainland at which traps are set are governed by the location of the shelf
edge. As shown in Figure A1.l, this shelf edge where coral development is greatest is on average
2 km from shore along the north coast but approaches a maximum of 20 km on the south coast.
Some 30% of the total number of fishermen operate on the north, with 70% on the south coast.
Of considerable significance is the high number of spearfishermen, especially on the north
coast where reefs are in closer proximity to the shore. These spearfishermen, who take fish and
crustaceans of all sizes, along with the collection of coral by curio vendors, have contributed to
the severe decline in reef fish on the north coast. There has been a considerable increase in the
numbers of spearfishermen, especially since 1978, due to the relatively low capital outlay
involved and the downturn in the economy.
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...Hurricane Gilbert...
Figure A1.1 Fishing areas of Jamaica and 200m isobath
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CEP Technical Report No. 4
The Status of Fishery Resources before Hurricane Gilbert
The fishery resources of Jamaica (including scalefish & lobsters) derive primarily from reef
environments and certainly around the island shelf are overfished and badly in need of corrective
management measures. Catch levels for the 20 year period 1968-1988 have remained at
approximately 7,000 tonnes annum-1 from the island shelf. This is despite almost a doubling in
effective fishing, effort during this period (Aiken & Haughton, 1987a; O'Callaghan, et al, 1988).
Fishing intensity has been shown by several researchers (Aiken & Haughton, 1987a, 1987b)
to have reached levels which brought about maximum yield from the island shelf fishery as long
ago as 1975/76. Since that time, the fishery has entered the overexploitation stage, typified by
declining catch rates as fishing intensity increases.
Overfishing of reef fishes has brought about alteration of the fish community structure itself,
where, for instance, there has been a significant decline in the abundance of predatory fishes,
such as snappers (Lutjanidae), groupers (Serranidae) and others which have the highest
commercial value. Simultaneously, catches have become dominated by less valuable species of
fish, such as parrotfishes (Scaridae), surgeonfishes (Acanthuridae) and squirrel-fishes
(Holocentridae) (Aiken & Haughton, 1987a).
The economics of the fishery has been altered negatively, therefore, and in real terms the
value of the catch is steadily declining. In some areas, where due to overfishing even the
herbivorous reef fish have been largely removed, algal growth has increased. An over-abundance
of marine algae can smother corals and, through wmplex dynamic interactions, reduce the ability
of the reef to support normal levels of reef fish ( O'Callagan, et al, 1988).
Reef Structure and Fishery Resources
Jamaican reef profiles or sections, as described by Goreau (19-59), Goreau and Goreau
(1973) and others, are typified by a clearly separated fore-reef and back-reef separated by a reef
flat and surf zone. Behind the last two zones are the rear zone (just behind the emergent reef flat)
and the lagoon zone. The areas routinely fished by traps are all in the fore-reef zone from
approximately 20 to 25 m down to a depth of 50 m. Most adults and sub-adults of some 180 reef
fish species and 4 species of lobster come from this fore-reef zone, while the smaller juveniles
generally inhabit the shallows.
Hurricane Gilbert Damage to Reefs
By way of introduction, the island can be divided into two zones to summarise the hurricane
damage, viz. a northern zone from Portland in the east to Hanover in the west, and a southern
zone from St. Thomas in the east to Westmoreland in the west.
The phenomena which affected fishery resources were as follows: (a) storm surge, (b) wave
action, (c) wind velocity, and (d) terrestrial run-off from storm precipitation.
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...Hurricane Gilbert...
(a) Storm Surge
Sea levels along the north coast generally rose less than on the south. Information suggests
that highest levels were recorded along the eastern section of the island, such as in
Portland. In this parish, much damage was done to coral reefs down to a depth of
approximately -20 in. The fore-reef all along this coastline was severely damaged by waves
accompanying storm surge. Storm surge, produced by the effect of high winds literally
piling up water in front of them, pushed seawater ashore into areas often well above the
reach of waves.
On many low-lying beaches there was considerable damage to boats (see fishing
infrastructure, below) due to these being swept ashore and broken up by waves and/or colli-
sion with immobile terrestrial objects.
Again, southern beaches had reportedly less storm surge and those visited in St. Thomas,
Kingston, St. Catherine and Westmoreland showed evidence of a surge of approximately
+1.5-2.0 m a.s.l. (above sea level). On the north coast surge level was somewhat higher,
apparently reaching about + 2.0 m along the northeast section.
(b) Wave Action
Wave action was apparently most severe on the northeastern section of Jamaica, where
wind velocity was highest and the coast most exposed. Fishing beaches reporting heaviest
damage were found in Portland, St. Mary and St. Ann. Lesser damage was reported also
from Trelawny, St. James and Hanover. Considerable damage was said to have been done
to mangroves in Trelawny, such as those near Falmouth. The most obvious effect was
considerable defoliation of all mangrove trees, breakages of stems and prop roots,
particularly in Rhizophora mangle, the red mangrove, at the water's edge.
Fishery Resource Nursery Areas
Most fishery resources (scalefish, crustaceans, etc.) have clearly defined nursery areas
(Ross, 1982), which may be summarized as shallow reef areas (-10 m) and inshore areas of
mixed coral, reef rubble and algae. Shallow Thalassia (Turtle grass) beds, mangrove areas and
some deeper reef areas are important as nursery grounds also.
Hurricane Gilbert's effects were probably greatest in just these areas which, due to their
shallowness, were those in which wave action and storm surge were greatest. Examination of
several typical nursery grounds on the north coast near Discovery Bay showed, however, that
only moderate disturbances had been done to Thalassia beds, even on exposed shorelines. This,
perhaps, is a considerable tribute to the wave-energy dispersing effects of the many blades of this
marine phanerogam. Undoubtedly, however, there must have been somewhat more damage to
nursery areas along the northeast coastline.
Visible effects in these areas were increased size of Thalassia "blow-outs" (eroded edges of
large seagrass beds), back reef rubble deposited on top of Thalassia, killing most plants, and
short stumps of these seagrasses where previously full grown plants flourished. Significantly
Page 33
CEP Technical Report No. 4
reduced abundance of juvenile fishes was quite apparent to observers in all areas examined
(Rocky Point, St. Thomas; Discovery Bay; Ocho Rios and Falmouth). Previously, numbers were
greater by approximately 50%.
Fishermen's Beaches
In all, it has been officially estimated that Hurricane Gilbert caused approximately J$25M in
damage to fishing beaches and Fisheries Division infrastructure, which includes outstation roof
loss/damage, fuel pump damage, etc., (R. MooYoung, personal communication). Generally, most
damage occurred on fishing beaches on the northeast coast, particularly Manchioneal and Buff
Bay in Portland, as these areas were completely exposed. Reports from the Fisheries Division
suggest that there was rather less damage on the south coast and that those fishing beaches with
gear sheds (with aluminium roofing) suffered some darmage. However, much of this damage on
the south coast has already been repaired by persons working on those beaches. Beaches on the
south coast reporting much gear shed roof damage include Rae Town, Greenwich Town and Old
Harbour Bay. These three beaches have many gear sheds provided for the fishermen.
On the north coast, the beaches at Manchioneal and Buff Bay were among ones with
particularly severe damage. At the former, the outstation and its pump were for a time
completely inundated by the sea and left buried in sand, beach rubble and boulders thrown up by
particularly severe storm surge and accompanying waves. At this beach the fuel pump may have
to be completely replaced and major structural repairs are needed to the outstation building. This
entire township it should be noted is only 20m from the shoreline and located almost at sea level;
it was especially battered by the sea. Buff Bay in western Portland also suffered particularly
heavy damage due to the entire beach being covered by many large boulders thrown up by the
storm surge and waves. Additionally, two groynes constructed to enhance sand entrapment on
this exposed beach were completely destroyed by wave action. The complete coverage by
boulders at the time of writing (November 1988) prevents proper usage of this beach by
fishermen as well as the public.
While not strictly part of this report, it should be noted that almost 90% of all traps were lost
and some 200 boats damaged islandwide. This results in considerable alteration in fishing
patterns following the storm. As replacement of traps is necessarily slow, as they are built by
artisans, the trap fishery is still depressed at present.
Discovery Bay Reef Damage and Fishery Effects
Discovery Bay reefs are well described in the literature and are known to support (barely) a
number of fishermen who operate out of two small sites, Top Beach and Old Folly. There are
two major fishing areas, the east fore-reef and west fore-reef. The former is the eastern limb of
the Bay, which is dominated by a broad, flat, relatively coral-free slope running into
approximately 30m where there is the "drop offs" fringed with coral. This area is convex shaped
and in Hurricane Allen (1980) the shape helped focus the waves and the highest breakers were
said to have been seen there (O'Callaghan et al, 1981). The west fore-reef encompasses all the
reef in front of the Discovery Bay Marine Laboratory. The reef is a series of well developed
systems of spurs and grooves which run alternately seaward and may be summarized as being
divided by depth into the following zone:
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...Hurricane Gilbert...
(1) Reef crest (0 to 2 m)
(2) Shallow fore-reef/Acropora palmata zone (-2 to -10 in)
(3) Acropora cervicornis zone (-10 to -20 m)
(4) Fore-reef (-20 to -50 in)
(5) First drop off (> -50 m)
The fishermen report that many traps were swept into deeper water by strong currents during
the hurricane and that fish catches were depressed afterwards for several weeks. Of major
importance is the loss of 50%, of all traps.
Diving in Discovery Bay showed that, as in the 1980 Hurricane Allen, there was
considerable damage to A. cervicornis (elkhorn coral) on the fore-reef, resulting in many of the
"fingers" being broken off and scattered on the sea floor in broken masses. In November, these
broken dead pieces were being colonised b various algae and were slowly becoming cemented y
into the reef floor.
Offshore Fishing Reefs
(a) Morant Cays
Hurricane Gilbert slightly damaged the wooden huts proved by the Ministry of Agriculture
as accommodation for fishermen on the Morant Cays on the eastern limb of the Morant
Bank, though not severely. All of these huts had zinc roofs and nearly all were damaged to
some degree. Due to the greater distance than Kingston from the eye of the storm, there
was not a great deal of storm surge and, thus, its effects were rather less (Morant Cays are
some 100 kin southeast of Kingston). Reports were received from fishermen of some coral
and coral rubble being thrown up on the beaches on these cays, suggesting that there was
some damage to shallow water corals. This may affect the survival of juvenile fish and
lobsters in that area.
As the hurricane occurred during the marine turtle egg-laying period, it may be assumed
that turtle nesting beaches, which are found especially on the smaller uninhabited cays,
may have been severely eroded by the storm surge.
(b) Pedro Cays
Much the same events occurred on the Pedro Cays, some 200 km to the southwest of
Kingston, where wind caused slight damage to the reefing of fishermen's huts. Storm surge
caused some damage to shallow water coral on the exposed east sides of the cays.
Kingston Fishing Port
The very high winds accompanying the passage of Hurricane Gilbert wreaked havoc with
the Kingston Fisheries Terminal at East Bustamante Port. All the facility was covered with
aluminium roofing and considerable damage was done to the ice factory, the canteen and the
covered market hall. The value of the damage to the fishing port is estimated at about J$500,000.
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CEP Technical Report No. 4
Additionally, two fishing vessels moored at the port were badly damaged by the storm and sank,
but were refloated later.
Oysterculture
The island has developed, since 1980 particularly, an oysterculture industry based on the raft
mariculture of the mangrove oyster, Crassostrea rhizophorae. In St. Thomas, Port Morant's inner
bay called Bowden was the major site of oysterculture due to its larger natural oyster population
and its easy access, as well as its relatively sheltered nature from waves and winds.
The grow-out or culture technology has been based since the inception of the project on the
use of artificial cultch surfaces, namely cut squares of vehicle types spaced about 10 cm. apart
and hung on monofilament lines suspended from large tethered rafts made of bamboo and empty
44 gallon oil drums.
Before the hurricane struck, Bowden Bay supported approximately 80 rafts, moored
throughout its reaches. During the hurricane, damage was caused by storm surge and wave
action. Storm surge from the open southern end of the bay piled many rafts into each other and
generally there was a movement northwards by the rafts. Many sunk and were smashed by high
waves. Generally, a 50% loss of all rafts was estimated, in addition to the loss of the roof of the
oysterculture office and workshed building. This loss has been estimated at about J$75,000 (see
footnote).
Oysterculture rafts in Port Antonio Harbour were damaged also by wave action and storm
surge, according to reports recieved. However, it is not known what losses were incurred as this
was a private facility. Oyster culture losses at Green Island, Hanover, are unknown at this time,
but were probably small as the activities are a small fraction of what occurs at Bowden.
Artificial Reefs
There were four artificial reefs in Jamaican coastal waters. The first and largest was at Jackson's
Bay, Clarendon, and the other three at Pigeon Island, St. Catherine, Rackham's Cay and South
Cay, Port Royal Cays. These reefs were constructed of motor vehicle tyres specially weighted
with concrete and tied into bundles of three to six tyres. Most of these reefs were constructed in
the mid 1970's and one in 1986 by the Fisheries Division, Ministry of Agriculture, and were
especially located in relatively shallow seagrass-covered embayments which are much like
lagoon environments. These reef sites, except Rackham's Cay, generally had coarse calcareous
sand floors with extensive turtle grass beds, scattered coral heads and small patch reefs. The
average depth for most sites was a proximately 10 m.
Editor's Note: Little damage appears to have been done to the natural oyster beds in Bowden Bay,
which are important as the main source of juveniles for the culture project.
Page 36
...Hurricane Gilbert...
Jackson's Bay artificial reef contained the highest number of tyres, over 3,000 (Haughton &
Aiken, in press) and others had lesser numbers. Several of the reefs were damaged by Hurricane
Allen in 1980 and the South Cay reef almost completely destroyed by having many of its tyre
bundles (modules) swept into deeper water by wave action at that time. In 1986, between
January and July, another reef of about 1,000 tyres set in 6 tyre modules was constructed at -25
to -30 m at South Cay. This reef is of unknown status as no reports or dives on it have been
made. However, the depth at which it is located would suggest that it would be undamaged as
wave damage did not generally affect the reefs below -20 m.
Reports suggest that there has been again some damage to the Jackson's Bay artificial reef
from Hurricane Gilbert. The effects of the damage are to reduce the carrying capacity of the reef.
The reefs at Pigeon Island and Rackham's Cay are extremely small and probably contribute very
little to fish enhancement as a result.
The monetary damage cannot be properly estimated at this time, but it would take
approximately 5 trips of the M.V. Dolphin (72 foot, double rigged Gulf shrimp trawler design)
fully loaded with 500 tyres per trip to replace a reef. If it is assumed that 500 tyres cost J$5 each
to be prepared and each trip costs J$2,000 in full, this total would be approximately J$13,000.
Socio-economic Effects
Generally the hurricane created problems, through physical damage to the infrastructure and
especially submerged fishing gear. Earning losses occurred also, especially among trap
fishermen due to these persons being unable to land catches for one week due to almost complete
loss islandwide of fish traps and damage to boats. Though it is not possible to give a precise
figure for these losses, it is known that at least 7-10 days passed before actual fishing resumed
islandwide, and then at levels considerably below normal. Even at the time of writing, 2 months
after the hurricane, levels of fishing are still depressed due to a shortage of mainly imported
meshwire to replace lost traps.
Furthermore, if we accept that approximately three vendors are supported by each fisherman
(Aiken & Haughton, 1986b), with 12,000 commercial fishermen in Jamaica approximately
38,000 vendors were affected and suffered earning losses for several days.
Summary
Hurricane Gilbert's direct hit on the island affected the fishing industry to a considerable
extent. There was almost a complete loss of active fish traps at sea, with approximately 5% of all
boats being damaged. Fishing beaches were considerably affected islandwide, but damage was
greatest along the northeast coastline, especially from Portland to St. Mary. Storm surge caused
significant reef damage down to approximately -20 m, especially among the ramose (branching)
corals. Most severe trap and. boat losses came from this section of the island. Nursery areas
were affected by erosion and reduction in blade length. Also noticeable were reductions in
juvenile fish numbers in nursery areas. The long term effects of this damage, coupled with severe
overfishing, cannot be predicted precisely at this time, but are likely to be considerable.
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CEP Technical Report No. 4
Damage to the oysterculture industry was severe also, with an estimated 50% loss of grow-
out (production) rafts with oysters, put at approximately J$75,000. The artificial reef at Jackson's
Bay was affected by storm surge and tyre modules were swept ashore. Replacement costs would
be about J$13,000. Deeper artificial reefs suffered less damage. Fishermen suffered significant
earning losses, especially trap or fish pot users who experienced approximately 90% losses.
Total islandwide fishing beach, trap, boat and fisheries infrastructure losses have been put at
approximately J$25M by the Ministry of Agriculture.
The effects on fishery resources have been considerable, in the opinion of this author,
especially in the northeast of the island. Other complex ecosystem interactions between fishes
and the damaged reefs are more subtle and more long-term and these effects will only become
apparent with time. Short- and medium-term effects may be much in keeping with observations
made after Hurricane Allen in 1980, when abnormally great quantities of various macroalgae
grew on the reefs smothering some corals already weakened by storm damage. Further
monitoring of the fishery effects of Hurricane Gilbert during 1989 is recommended.
Reference
Aiken, K.A. & Haughton, M.O. 1987a. Status of the Jamaican reef fishery and proposals for its
management. Proc. 38th Ann. Gulf & Caribb. Fish. Inst. Nov. 1985. Martinique, University of
Miami Press; 469-484.
Aiken, K.A. & Haughton, M.O. 1987b. A Management Plan for the Jamaican Fishery. Report
to the Ministry of Agriculture Science & Technology; 42 pages.
Goreau, T.F. 1959. The Ecology of Jamaican Coral Reefs: 1. Species composition and zonation.
Ecology, 40; 67 -90.
Goreau, T.F. & Goreau, N.I. 1973. Coral Reef Project - papers in memory of Dt. T.F. Goreau,
17. The ecology of Jamaican coral reefs. 11. Geomorphology, zonation and sedimentary phases.
Bull. Mar. Sci. 23 (2); 399 - 464.
O'Callaghan, PA., Woodley, J.D., Aiken, K.A. & Haughton, M.O. 1988. Marine Park
Development in Jamaica. Report to the OAS Tourism Development Plurinational Project,
Montego Bay, Jamaica; 205 pages.
Ross, F.E. 1982. Distribution, Abundance and Development of Young Jamaican Reef Fishes
Pt. 3(2) Fish nursery grounds. Scientific Report ODA/UWI Fish. Ecol. Res. Project, 1974 1979,
Zoology Department, University of the West Indies, Mona; 121 pages.
Received: 5 November 1988
Page 38
...Hurricane Gilbert...
Appendix 2
HURRICANE DAMAGE AT PORT ROYAL
By: Gerard Alleng
Zoology Department
University of the West Indies, Jamaica
Damage to the mangrove areas of Port Royal was widespread, with approximately 30% of
trees being severely damaged or destroyed. The fringe areas of the mangrove experienced the
heaviest toll, especially on the Kingston Harbour side, i.e. the northern and northwestern areas of
the swamp. The main damage was to red mangrove (Rhizophora mangle) but large trees of red,
black (Avicennia germinans) and white (Laguncularia racemosa) mangrove were all damaged. A
large number of the black mangrove trees were uprooted and the area experiencing, heaviest
damage was Refuge Cay, which was also an important rookery for a number of birds. A
photographic record was obtained.
Defoliation of mangrove trees tended to be high; at one sampling station in the fringe
mangrove area litter fall was estimated at greater than 149 g m-2 day-1 (dry weight). (It is not
known how effective litter sampling traps were during the hurricane, as some leaf material may
have been blown out of the traps. The measurement is an approximation, therefore).*
Data received from the Meteorological Office, Norman Manley Airport, indicated that 223.4
mm of rain fell on September 12th. Freshwater inputs to Kingston Harbour lowered the salinity
for several days after the Hurricane. Surface water samples showed the following:
Date Salinity
o/oo
Sampling
station
14 Sept.
14
Port Royal Marine Lab.
17 Sept.
22
Port Royal Marine Lab.
17 Sept.
18
Port Royal mangroves
17 Sept.
18
Plumb Point Lagoon
Received: 9 December 1988
* Editor's note: Unpublished data from Falmouth Rhizophora forest give a maximum litter fall
of 6 g m-2 day-1.
Page 39
CEP Technical Report No. 4
Appendix 3
SURVEY AND ASSESSMENT OF HURRICANE DAMAGE TO WETLANDS
By: Dr. Peter R. Bacon
Zoology Department
University of the West Indies, Jamaica
The following is a catalogue of observations on wetlands in several parts of the coast of
Jamaica (Figure A3. 1), made during on-the-ground and air surveys in November and December
1988 and January 1989. Reference should be made also to data on wetlands which appears in
other Appendix reports. Notes are included also on the associated littoral woodland vegetation,
where appropriate.
A. SOUTH
COAST
(1) Great Morass, St. Thomas
(28.11.88) Extreme defoliation observed, over 75% of mangrove area, with severe
breakage to upper branches and about 30% trunks. This was confirmed by John Lethbridge
(personal communication), who noted also evidence from the air of rain flooding and run-off
induced erosion effects around the Morass.
(2) Palisadoes
(24.11.88) Low level of damage to Palisadoes mangroves and littoral woodland (near
airport); breakage of upper branches and some defoliation. Large trees lost tops and upper
branches, but uprooting not observed. Trunks of Rhizophora (red mangrove) up to 15 cms d.b.h.
(diameter at breast height) shattered at between 4-5 m above ground. Estimate 50% of mangrove
fringe showing some damage.
The presence of a thick ground cover of propagules and germinated seedlings should lead to
rapid regeneration of the mangrove area. Mangrove trees in this area have little direct economic
value, except minor cutting for charcoal and poles. Increase in fallen timber expected to provide
increased supplies of wood for the charcoal industry.
(3) Kingston Harbour/Port Royal
(09.12.88) Air survey: Considerable damage evident around Dawkin's Pond, but this is
probably due to cutting and clearance rather than the hurricane.
At Port Royal hurricane damage is most severe on the northern (harbour) side, with 10- 20%
breakage. 10% of trees down, largely Rhizophora, with about 30% defoliation.
Page 40
...Hurricane Gilbert...
(4) Hellshire
(24.11.88) Rhizophora all round the Great Salt Pond (D'Aguilar's Pond) lost tops and upper
branches, but few main stems broken. Uprooting of Rhizophora not observed.
As above, well developed ground cover of juvenile mangroves. Some cuttting for charcoal
in Hellshire, but little around the main pond.
(09.12.88) Air survey: Severe damage all round Great Salt Pond, with defoliation and
fallen trees (Figure A3.2). Long Pond mangroves only slightly defoliated, minor breakage. The
Flashes area shows 20-30% of trees fallen, but there is evidence of much cutting of mangrove
and other timber and active charcoal burning. Percentage of damage caused by hurricane not
clear.
(09.12.88) Air survey: Wreck Bay - Hellshire Point mangrove area showing 20-30%
breakage, particularly to old Rhizophora, but only two or three fallen.
(5) Fresh
River/Ferry
(08.12.88) No damage evident to mangroves or herbaceous wetland areas on south side of
the Washington Boulevard/Spanish Town Road. Water levels as normal over the past two years;
egrets and other waterbirds feeding as normal.
1~
(6) Canoe
Valley
(09.12.88) Air survey: No conspicuous damage to tree vegetation and no flattening of
herbaceous wetland plants.
(7) Milk
River
Bay
(09.12.88) Air survey: 10-20% upper branch damage, particularly in tall back mangrove
area. Defoliation not conspicuous on fringe areas. Eroded mangrove is present all along the bay,
with much undercutting by wave action. This has been noted previously and cannot be
distinguished as due to the hurricane.
(8) Macarry
Bay
(09.12.88) Air survey: High mangrove at back inland side of the lagoons showing broken
and fallen trees; damage 10-20%. Large quantities of tree debris, including some mangroves, off
the mouth of the Rio Minho. Large flocks of waders present in this area.
(9) West
Harbour
(09.12.88) Air survey: The mangrove fringe of the main harbour/lagoon area shows little
hurricane damage. Northwest area fringe with minor defoliation and branch damage, but
widespread defoliation and mortality in the back swamp areas (which had been observed prior to
Page 41
CEP Technical Report No. 4
Figure A3.1 Wetland Locations
Page 42
...Hurricane Gilbert...
Hurricane Gilbert). Some of this mortality may be related to pond fish culture and salt production
activities in the area, while normal mangrove successional effects are thought to be involved in
other areas.
Similarly, some mortality has been observed previously in the centres of small overwash
mangrove islands in the eastern harbour mouth area; making the detection of hurricane damage
difficult. The seaward fringe/barrier islands area showed minor defoliation and branch damage,
3-% in upper parts only. Dolphin Island showed slight defoliation all across, but particularly on
the eastern fringe.
(10) Rocky Point
(09.12.88) Air survey: There was existing severe damage to the mangrove environment
prior to the hurricane, so storm damage cannot be assessed. Burial Ground mangrove area is
virtually devoid of living trees and there is much mortality on either side of the road to the
bauxite dock.
(11) Salt River Bay/ Cockpit-Salt River Swamp
(09.12.88) Air survey: Some defoliation evident on Long Island, about 10%. No damage
evident north of Salt River; the large area of marsh showed no evidence of flattening or other
disturbance. North of the Cockpit River about 10% of trees fallen.
(12) Goat Islands
(09.12.88) Air survey: 20-30% defoliation along south mangrove shore, especially between
Little and Great Goat Islands. At the southeast tip of Great Goat Island 5-10% of trees fallen.
(13) Cabarita Swamp (St. Catherine)
(09.12.88) Air survey: Cabarita Swamp had much dead and dying mangrove, particularly in
the inner basins, prior to the hurricane, so this cannot be distinguished readily from storm
damage. In the main (western) part of the swamp there was no evidence of defoliation or other
damage, no trees fallen in fringe areas. Southeast area fringe, following round through the
Needles west of Coquar Bay, 10-20% defoliation only.
(14) Coquar Bay - Manatee Bay
(09.12.88) Air suvey: Minimal breakage evident, less than 5% loss of leaves and branches,
although clearly evident in some areas. Some defoliation in taller trees in the back swamp areas.
No damage or defoliation evident at Old House Point.
Page 43
CEP Technical Report No. 4
Figure A3.2 Percentage defoliation and branch breakage around Great Salt Pond, Hellshire,
and areas of destructive human impact
Page 44
...Hurricane Gilbert...
B. NORTH
COAST
(15) Mammee Bay (St. Ann)
(08.12.88) Much damage to the foreshore and littoral vegetation, which included toppling
of several old Conocarpus trectus (button mangrove) trees (Fig. A3.3).
Some defoliation and breakage to mangroves at the western end of the beach also.
(16) Priory
(08.12.88) Relatively little damage to mangroves; some fringe Rhizophora with top
branches broken at 3 m above ground (Fig. A3.4). Little defoliation and branch loss, about 5%,
on the eastern/windward side.
(17) Llandovery
It
(08.12.88) Minor damage to low fringe Rhizophora, about 5% upper branch breakage. Two
to three large Laguncularia trees fallen, and sand and coral debris thrown into wetland for about
30-40 m where it has covered the mud surface (Fig. A3.5). Crabs (Cardisoma) have already
burrowed through this coating of sand. Wave surge has thrown debris across the garden of the
adjacent resort and water damage is evident in the wetland south of the track.
Large quantities of seagrass debris thrown among prop roots of the mangrove fringe (Fig.
A3.6). Algal epiphytic growth on the prop roots does not appear to have been damaged.
(18) Pear Tree Bottom
(29.11.88) Littoral woodland zone severely damaged, including loss of some button
mangrove (Conocarpus) and small Rhizophora (Fig. A3.7). The stand of tall Rhizophora in the
central part of the bay used as a roost by egrets and other waterbirds lost two main trees and the
tops of several others (Fig. A3.8). Coral rubble and tree debris thrown across road into main
wetland area. No visible damage to herbaceous vegetation in the wetland; common waterfowl
(moorhens and egrets) present in the expected numbers.
(01.01.89) Despite damage from the hurricane, birds still use the mangrove trees for
roosting. Observations between 1740-1810 hrs showed the following numbers:
Cattle egret (Bubulcis ibis)
Little blue heron (Florida caerulea)
(19) Crater Lake, Discovery Bay
(29.11.88) Tall mangrove thinned out (Fig. A3.9), with loss of trees throughout the stand
and much defoliation.
Page 45
CEP Technical Report No. 4
(08.12.88) Trees up to 28.4 cm d.b.h. fallen, by bending over or crushing of the trunk just
above the prop roots rather than being uprooted (Fig. A3.10). Upper part of forest torn out at
from 5-6 in above ground level, with loss of vines and epiphytes. Ground litter of mangrove
leaves, vine leaves and stem material of between 300-500 g m-2, compared with previous
standing litter crop at 200 g m-2. Prior to the hurricane vines were particularly abundant on trees
along the roadside fringe; these were not a natural part of the mangrove forest so their loss may
be beneficial to recovery of the forest.
Peter Reeson (personal communication) reports a similar situation in the Royal Palm Forest
Park in the Negril Great Morass, with damage to about 30% of the palms by defoliation and
removal of epiphytes; particularly Phyllodendron and Ipomoea, whose growth had been
promoted by man-made clearings in the forest.
Dense ground cover of mangrove seedlings was observed and much more light is reaching
the forest floor as a result of removal of much of the canopy at Crater Lake.
Mangroves fringing Crater Lake itself appear not to have been damaged by Hurricane
Gilbert.
(30.12.88) Fallen trees at Crater Lake were oriented generally south or south-south-west,
suggesting that they were felled by winds from the north or north-north-east sector.
Measurements made in the northern area of the Crater Lake mangroves, where damage was
most severe, showed approximately 60% of Rhizophora trees broken or fallen. Damage was
spread over an area from 50-100 m wide for about 600 in parallel to the main road, or about
4.5 ha. Loss of potential timber crop from this mangrove stand was estimated at approximately
2,000 m.
(20) Rio Bueno
(08.12.88) West of the town, large quantities of coral debris and sand thrown into littoral
woodland and mangrove fringe. Scrub Rhizophora and Laguncularia uprooted and upper
branches damaged along western margin (Fig. A3.1 1).
The calculation was based on data previously recorded on forest structure at Crater Lake and
measurements of fallen timber sizes, as follows:
Density of trees
1,800 ha-1
Mean length of usable timber
15 m
(above buttresses, below small branches)
Mean circumference of fallen trees
60 cm
Mean timber volume per tree
0.4 m3
Timber volume in plot
720 m3 ha-1
Page 46
...Hurricane Gilbert...
Figure A3.3 Damage to Conocarpus, Terminalia and coconut trees at Mammee Bay.
Figure 3.4
Minor wind damage to fringe Rhizophora at Priory.
Page 47
CEP Technical Report No. 4
Figure A3.5 Sand thrown into wetland at Llandovery.
Figure A3.6 Seagrass blade debris thrown into fringe Rhizophora at Llandovery.
Page 48
...Hurricane Gilbert...
Figure A3.7 Littoral woodland, including Conocarpus and Laguncularia. uprooted at Pear
Tree Bottom.
Figure A3.8 Damaged Rhizophora at the egret roost at Pear Tree Bottom.
Page 49
CEP Technical Report No. 4
A good ground cover of mangrove seedlings was present, so that some regeneration of the
forest is expected. Measurements made in two study plots gave the following data:
Mean number of Rhizophora seedlings
12 m-2
Mean height of Rhizophora seedlings
56.88
cm
Size range of Rhizphora seedlings
42 to 104 cm
Mean number of Laguncularia seedlings
55 m-2
Mean height of Laguncularia seedlings
17.27 cm
Size range of Laguncularia seedlings
12 to 30 cm
Seedling have been labelled in the sample plots for further study of Growth and
regeneration in the forest stand.
(21) Trelawny Beach Hotel
(29.11.88) Major part of mangrove area east of the hotel suffered some damage, but largely
as broken upper branches and some defoliation. Mangrove on western side is being cut and
cleared or filled in.
(22) Falmouth
(29.11.88) Florida Lands area, east of Glistening Water, much thinned and over 50% de
foliated (Fig. A3.12) with breakage to upper branches and loss of nearly all tall trees. 50-60% of
the felled (Fig. A3.13). Trunks were broken above the buttresses; but there was little disturbance
to the prop roots and no uprooting
Unpublished data from an April 1986 forest mensuration study at Florida Lands show there
were only 12 trees in a 300 m2 plot, with the following characteristics:
Parameter Mean
size
Largest
tree
Height of tree
16 m
20 m
Height of but tresses
4.6 m
6 m
Diameter (breast height)
23.3 cm
35.7 cm
Large quantities of dead mangrove debris, including large trunks, from the dyked area to
the east of the remaining live mangrove, was washed onto the dirt road and into the mangrove
fringe. Debris showed signs of having been transported from NE to SW, probably by wave surge.
Stands of black mangrove on south side of the road heavily damaged with only 10-20% of
trees uprooted, but about 80% defoliated (Fig. A3.14).
(29.12.88) Florida Lands, much standing water; waterbirds present in small numbers.
Pelicans and little blue herons still roosting on mangroves at the eastern margin of Glistening
Water Bay, despite the tree damage.
Page 50
...Hurricane Gilbert...
Figure A3.9 Wind damage to tall Rhizophora basin forest at Crater Lake, Discovery Bay
Figure A3.10 Rhizophora tree bent above the buttresses at Crater Lake, Discovery Bay.
Page 51
CEP Technical Report No. 4
(01.01.89) Mangrove area immediately east of the Martha Brae River, north side, showing
little damage; previous records show that this site had lost the majority of the large trees to
charcoal cutters before the end of 1987.
(29.11.88) Main road west of Martha Brae River, with some Rhizophora and Laguncularia
uprooted in coastal fringe. Hague Swamp area, south of road, showing moderate damage; some
slight defoliation of scrub mangroves and drying of large areas of Acrostichum, the latter
possibly as a result of storm surge throwing salt water over the fronds of this swamp fern.
Half Moon Bay mangrove area, west of Falmouth Town, appears greatly thinned out, but
this may be as a result of charcoal burning rather than the hurricane. Previous records show that
the majority of large mangrove trees had been removed before the end of 1987.
Safari Park mangrove area, west of Falmouth Town, 30- 40% defoliation of mangroves
north of the road, several trees down and much upper branch breakage.
(23) Salt Marsh
(29.11.88) South of the road: all the Rhizophora has gone from the western side of the main
pond; but appears to have been cleared for a construction camp rather than by the hurricane.
South of the road, west of the pond, the stand of mature Avicennia has been severely
damaged. There is almost 100% defoliation, and 40-50% of trees uprooted. Fallen trees are
oriented in a southwesterly direction (Fig. A3.15). The stand has sparse seedling cover, but
scattered young trees and some coppice regrowth, both at about 2 m high.
North of the road: Some defoliation and 25-30% breakage to upper branches.
The landward side of Saltmarsh Lagoon showed similar damage. However, sessile biota
attached to mangrove roots on this side of the Lagoon appear not to have been disturbed.
Populations of the flat tree-oyster, Isognomon bicolor, the mussel, Brachidontes citrinus, and
common algal species show densities similar to those recorded previously.
The seaward side Rhizophora fringe of Saltmarsh Lagoon showed severe defoliation and
upper branch breakage. Damage was spread throughout the whole stand, and marked above
3-4 m.
Egrets and herons still roosting on damaged trees in the central part of the mangrove fringe.
Page 52
...Hurricane Gilbert...
Figure A3.11 Coral debris thrown into wind damaged fringe mangrove and littoral woodland,
Rio Bueno.
Figure A3.12 Defoliation of tall Rhizophora, Florida Lands, Falmouth.
Page 53
CEP Technical Report No. 4
Figure A3.13 Tall Rhizophora broken above the buttresses, Florida Lands, Falmouth.
Figure A3.14
Defoliated Avicennia woodland, east of Falmouth
Page 54
...Hurricane Gilbert...
Figure A3.15 Uprooted Avicennia trees, Salt Marsh.
Figure A3.16 Defoliated and felled trees, Wyndham Rose Hall wetland.
Page 55
CEP Technical Report No. 4
(24)Seacastles/Wyndham Rose Hall Wetland
(29.11.88) Storm damage includes breakage to 20-25% of trees, largely Laguncularia,
Conocarpus and mahoe. Defoliation of most of high branches (Fig. A3. 16). Less than 10 trees
uprooted and fallen; major damage appears as slight displacement of sprouting coppiced
Laguncularia, which show the northern side of the knolls uprooted and/or loosened. The wetland
appears to have restabilised after the hurricane (see Greenaway report below), as freshwater
aquatic plants and waterfowl populations appear riot t6 have been damaged by salt water wash or
spray.
(25) Wyndham Rose Hall to Montego Bay
(29.11.88) Similar level of damage all along on north side of main road; 25-30% upper
branch breakage and severe defoliation, but little uprooting.
Received: 8 January 1989
I
Page 56
...Hurricane Gilbert...
Appendix 4
POST HURRICANE GILBERT REPORT: LLANDOVERY AND PORT ROYAL
By. Pamela Clarke
Zoology Department
University of the West Indies, Jamaica
(1) Llandovery (St. Ann)
The site was visited approximately two weeks after Hurricane Gilbert. Before entering, the
mangrove, a grassy lawn is normally encountered. This area, approximately 30 in wide from the
shore inland, was completely covered with sand and coral debris. The depth of the covering was
approximately 6 cm. The moist, black surface of the mangroves was also covered with sand. It
was noted that the sand covering did not extend to the landward limit of the mangroves, but only
for about 20 in from the beach.
Another clear result of Gilbert was the loss of leaves in the mangrove canopy; about 60%
defoliation. Sunlight penetrated the mangroves more readily than before Gilbert, making the
environment very hot.
The number of broken tree limbs and trunks was minimal, approximately 10-15%. Progress
through the mangrove area was not impeded by fallen or broken branches.
The sand bar running parallel to the beach which was previously below the water surface at
low tide was now clearly visible. A fisherman was seen standing on the bar above water level.
(2) Port
Royal
Mangroves on the north side of the Palisadoes near Port Royal were surveyed three to four
weeks after the Hurricane; the site being close to Warlands - second cemetery. Compared to
Llandovery, there was approximately three times as much damage to trunks and branches. The
once clear pathways from road to lagoon were impassable.
Red mangroves sustained the most damage. This was very distinct in the region behind the
cemetery. The black mangroves appear to have been more resilient. Within some areas the
degree of loss in the canopy was greater than others. Again, the region behind the first cemetery
suffered a loss of approximately 50%, compared with the region between Warlands and the Old
Naval Cemetery which experienced a loss of less than 10% in the canopy. The usually cool
mangrove environment was much hotter as a result of loss of the canopy. There was also a
marked odour coming from the mangrove substratum, suggesting that hurricanesurge or waves
had disturbed the decomposing organic matter in the sediments.
Page 57
CEP Technical Report No. 4
Few termite nests were thrown to the ground following breakage of their supports (4 out of
34 counted earlier). Some large nests remaining on their supports had been loosened, where they
are normally firm to the touch. Loss of outer nest material was evident in places, probably due to
damage by failing timber, but had been patched up by the time of the survey.
Among the mangroves fringing the lagoon there was marked increase in the level of solid
waste pollution. Large numbers of drink cartons and other debris were observed. This suggests
that floodwaters had washed increased quantities of garbage into the Harbour.
Received: 10 December 1988
Editor's Note:The effects of greatly increased quantities of fallen timber and damaged branches on
termite populations in mangrove areas require investigation. Increase in potential food supply may
be offset by the accompanying habitat damage in mangrove environments.
Page 58
...Hurricane Gilbert...
Appendix 5
PHYSICAL AND CHEMICAL EFFECTS OF HURRICANE GILBERT ON
THE WETLAND ADJACENT TO WYNDHAM ROSE HALL HOTEL
By: Anthony M. Greenaway
Department of Chemistry
University of the West Indies, Jamaica
(The following data results from studies done under contract to Caribbean Environmental
Consulting Services Ltd., and is reproduced by kind permission of Mr.John Algrove,Urban
Development Corporation, Kingston.)
In the small coastal wetland adjacent to the Wyndham Rose Hall Hotel, St. James, the
effect of Hurricane Gilbert was to raise the water level and alter the specific conductivity of the
water. Water level was measured at a stave at Site 1 (Figure A5.1). Conductivity changes
differed at different sampling sites.
Water level rose slightly at Site 1, but returned to pre-hurricane levels within one month.
Conductivity at Sites 1 and 6 rose to approximately twice pre-hurricane levels, and was slightly
elevated at Site 5, suggesting that sea water had entered the normally isolated wetland. At the
more landward Sites 7 and 9, a decrease in conductivity indicated increased input of fresh-water,
probably from increased surface run-off. Conductivity levels had begun to return to pre-
hurricane levels one month later (Table A5.1).
Table A5.1
Water Level and Conductivity at Wyndham Rose Hall Wetland
Parameter pre-hurricane
post-hurricane 1
post-hurricane 2
23.08.88
01.10.88
29.10.88
Water
level
(cms) 64.0 73.0 57.5
Conductivity Site 1
1720
4800
3800
(microMhos) Site 5
3800
4100
-
Site 6
2700
5200
4300
Site 7
3250
2700
2430
Site 9 Site 9
3200
1680
2520
Received: 14 December 1988
Page 59
CEP Technical Report No. 4
Figure A5.1 Sampling sites in wetland at Wyndam Rose Hall
Page 60
...Hurricane Gilbert...
APPENDIX 6
EFFECT OF HURRICANE GILBERT ON BEACHES AND THE STATUS
OF COASTAL OIL POLLUTION
By. Margaret A.J. Jones
Zoology Department
University of the West Indies, Jamaica
Beach profiles and general environmental conditions and levels of beach tar have been
recorded on 28 beaches around Jamaica (Figure A6.1) over a 13 month period, December 1987
to December 1988. After Hurricane Gilbert these beaches were surveyed on the following dates:
- South coast
- Saturday, September 24
- West coast-
- Saturday, September 24
- North coast
- Sunday, September 25 & Thursday, October 6
- East coast
- Thursday, October 6
- Kingston Harbour
- Thursday, October 6
(1) South Coast: Blueflelds, Parker's Bay, Gut River, Barnswell
Beach profiles on the south coast remained more of less the same and so did the status of
oil pollution.
At Barnswell there was a large quantity of dried and rotting Thalassia testudinurn, as well
as beach litter, but this was the case before the Hurricane also. Oysters were being cultured on
cultch hung from peripheral prop roots of Rhizophora mangle and these were intact and not
entangled. This is testimony to how little damage occurred to this section of the mangroves.
However, the growth of Crassostrea rhizophorae has been stunted, which may be due to
increased sediment.
Levels of stranded beach tar before (August, 1988) and after (Sept/Oct, 1988) the event are
shown in Table A6. 1.
Water samples for the analysis of dissolved and/or dispersed petroleum hydrocarbons
(DDPH) have also been collected before and after the hurricane. Analysis of these will indicate
the effects of terrestrial run-off.
(2) West Coast: Negril, Bloody Bay
The beach at Bloody Bay was covered with rotting blades of Thalassia testudinum, shells,
driftwood and litter as far as the back beach vegetation. This beach is normally free of driftwood
and litter. The sand was "mushy" and difficult to walk on as a result of layers of seaweed, sand
and water beneath. The beach behind Negril Village, beside the jetties, appeared the same.
However, as an important tourist area there was ample time for it to have been cleaned, as this
survey took place 12 days after the hurricane.
The status of oil pollution remained the same.
Page 61
CEP Technical Report No. 4
(3) North Coast: Hope Bay, Annotto Bay, Ocho Rios, Mammee Bay, Pear Tree Bottom,
Discovery Bay, Rio Bueno, Burwood, Montego Bay & Sandy Bay.
Generally, the beaches on the North Coast showed severe sand erosion, which exposed
roots of trees, piled banks of sand up to 1 m high amidst the vegetation and piled dried and
rotting seaweed on the beaches.
At Annotto Bay, the beach was strewn the whole length with driftwood-and litter about 5 m
wide, makina it almost impossible to get from the road to the waterline.
The beach at Discovery Bay is normally accessed through mangroves and rocky shore.
Many of the mangroves were uprooted and removed from the waterline, branches were broken
and entangled. Getting to the beach through the mangrove after the hurricane was easier than
before, as there was now a clear pathway and a reduced number of trees. The beach was orig-
inally coral rubble (thrown up from Hurricane Allen, 1980) on top of rock slabs. At the time of
this survey the rocks were visible and the coral rubble had been thrown up to and among the
vegetation, which is about 20 m from the waterline. The areas with the coral rubble and
extensive mangroves and other foliage look "scoured". Oil melted onto rock surfaces and tar
balls previously caught amongst prop roots remained the same. In "Scoured" areas a few pieces
of tar were found, but most had been thrown to the backbeach. Some fresh pieces of tar were
found, which may have been brought up by the Hurricane. Oysters being cultivated under a
finger pier were intact, but the strings and cultches were entangled with each other.
At Rio Bueno, the beach was also coral rubble and this rubble is now strewn away from the
beach area to cover the pasture land between the beach and the road. The road is approximately
60 m from the beach. No tar was visible after the Hurricane.
(4) Eastern Coastal area: Lyssons, Bowden, Holland Bay, Manchioneel, Long Bay, Blue
Hole.
The beaches at Lyssons, Bowden and Long Bay appeared to be only slightly changed, with
much redistribution of sand. The status of oil pollution remains the same. The most severely
damaged beach was Holland Bay, which now has a very distinct storm beach profile. Originally,
this beach was gently sloping and about 30 - 40 m wide from the waterline to stable vegetation (a
coconut plantation). The beach is now quite flat with a verticial sand berm about 1 m high on
which the coconut trees stand. It appears that the roots of the trees prevented further erosion. The
course of the river which empties in this area was lightly altered.
Older pieces of tar were found adjacent to the berm and fresher pieces, as usual, closer to
the waterline. The oil pollution at Holland Bay and Manchioneal does not appear to be
significantly different from the previously recorded level.
The road leading from Blue Hole was impassable, as it was completely broken away by
wave action. Sand was thrown up to form a bank about 1.5 m high against a brick wall that is
about 10 m from the waterline. Oil pollution status remained the same.
Page 62
...Hurricane Gilbert...
Coconut trees fringing the beaches of the east coast were badly damaged; branches totally
or partially torn off, roots exposed and whole trees uprooted. At Holland Bay, for every tree that
was left standing at least five were down. The vegetation was badly damaged at this site making
the entire Bay visible from a point just off the main road, which was not possible before.
There was considerable slumping and collapse of the cliff area near Hector's River.
Information received suggests that oyster culture racks at Bowden were damaged by the
Hurricane with consequent economic losses.
(5) Kingston Harbour and its Environs: Plumb Point, Great Salt Pond
Because of the nature of the rocky shore environment at Plumb Point (huge boulders and
rock slabs) no physical change in the coastline was observed. Visible oil pollution occurred as tar
melted onto rock surfaces and, therefore, the amount remained the same. At Salt Pond Beach,
there was a large amount of litter, driftwood and specks of fresh tar before the Hurricane and this
situation remained unchanged after the event.
Mangrove oysters, Crassostrea rhizophorae, were being cultured for experimental purposes
under a board dock at the Port Royal Marine Laboratory. There was complete structural damage
at the dock with total loss of the oysters.
Conclusions
The beaches on the eastern and north coasts were more severely damaged, as was visible
by the extent of sand erosion, exposed roots, uprooted trees and scouring. The south coast
beaches appeared not to have sustained as much damage.
From the data presented (Table A6.1), it can be seen that oil pollution by beach tar
occurred mainly in three areas of the island. After the Hurricane, the pollution was still restricted
to these areas although there were variations in the actual quantities of tar found at individual
sites. In some cases there was more tar, in other cases there was less. It must be noted that over
the whole sampling period there was variability in the amounts of tar found at each site from
month to month. Until all data is collected and properly analysed, firm conclusions should not be
drawn on the two month's data presented.
However, on the north coast the absence of tar after the Hurricane is anomalous, as tar was
always recorded at those sites. It appears that some of the tar was washed out to sea and some
was thrown amongst the backbeach vegetation.
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CEP Technical Report No. 4
Figure A6.1 Levbels of Stranded Tar (g m-1)
Site
August 1988
Sept/October 1988
Negril 0
0
Bloody Bay
0
0
Sandy Bay
0
0
Montego Airport
0
0
Montego Freeport
13.4
0
Falmouth 0
0
Burwood 546.6
0
Rio Bueno
37.4
0
Discovery Bay
4075.4
605.0
Pear Tree Bottom
10.9
0
Priory 4.5
0
Mammee Bay
7.3
0
Ocho Rios
0
0
Annotto Bay
0
0
Hope Bay
0
0
Blue Hole
0
0
Long Bay
0
0
Manchioneel
20.6
86.1
Holland Bay
186.0
95.9
Bowden
0
0
Lyssons
0
0
Salt Pond Beach
7.0
77.9
Plumb Point
10%
10
Barnswell
192.7
65.2
Gut River
0
0
Alligator Pond
0
0
Parker's Bay
0
0
Blue Fields
0
0
* recorded as % cover of rock surfaces
Received: 28 November 1988
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...Hurricane Gilbert...
Appendix 7
EXTRACTS FROM NATURAL RESOURCES CONSERVATION
DEPARTMENT. FILE NO. 11/2/7 - HURRICANE GILBERT 1988
Made available by Dr. Marcel Anderson
Natural Resources Conservation Department
The following extracts are taken from memorandA and notes made following field
surveysconducted from 20th to 27th September 1988. The Natural Resources Conservation
Department (NRCD) has a collection of colour photographs taken during these surveys.
Localities mentioned in this list are shown in Figure A7.1.
(a) Memorandum: L. Gardner, P. Campbell, E. Foster, 20.09.88
Survey from Turtle River to Cibony:
(1) Public Beach West of Fishermen's Point
Beach erosion up to 35 ft. Mouth of Turtle River blocked by sand and debris.
(2) Mallard's
Beach
Wave action 25-30 ft, shown in damage to tree roots.
(3) Americana
Hotel
Beach
Accumulation of reef debris.
(4) Hotel
Sombra
Major sand loss from the beach.
(b) Memorandum: L. Thompson, J. Taylor, P. Campbell, 22.09.88,
Portland and St. Mary:
(5) Annotto
Bay
Sand accretion and much debris giving foul odour to the water. River at western end
with mouth opened to the sea.
Page 65
CEP Technical Report No. 4
Figure A7.1 Beach Localities
Page 66
...Hurricane Gilbert...
(6) Lynch Park Bathing Beach
Sea came 100 m into coconut trees.
(7) Buff
Bay
Main road under water during the Hurricane, as shown by accumulated debris. Sand
accretion at Buff Bay Seaside Park.
(8) Orange
Bay
Sand accretion. Fresh corals, Acropora, Montastrea and brain coral, thrown up on the
beach.
(9) Hope
Bay
Sand
accretion.
(10) St. Margaret's Bay
Sand removed from the beach. Evidence of flooding across the roadway.
(11) Norwich Beach
Notes "reappearance of the beach".
(12) Port Antonio
Sand accretion in the East Harbour. Many coconut trees down and high of debris on
the shore.
(13) San San Beach
Loss of littoral trees.
(c) Memorandum: L. Gardner, 0. Morgan, 26.09.88
St. Ann.
(14) Public beach between Turtle River & Sailor's Hole River
Erosion to 12 m. Sand deposited at back of beach.
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CEP Technical Report No. 4
(15) Fishermen's Beach - Ocho Rios
Erosion to 10 m. Wave surge reached to 180 m. Sand accumulation at the back of the
beach.
(16) Between Fishermen's Beach & Bauxite Pier
Wave heiaht estimated at 7 ft (from broken littoral trees); shoreline cliff behind bus
shelter eroded.
(17) Dunn's River Falls Beach
Significant sand deposit at back of the beach. Much coralline debris on the reef West
of the beach.
Wave height estimated by local resident as 20 ft; but damage to littoral vegetation
suggests it was more like 12 ft.
(18)
Eden
II
Eastern beach eroded to 60 m inland; sand loss replaced by pebbles. Some sand
thrown up onto back beach. Much of the littoral vegetation uprooted.
Western beach accreted.
Highest waves 3-5 ft, at 8-20 m from the waterline. Waves estimated at 30 ft at the
reef by an observer.
(19) Mammee Bay Estates
Erosion extensive to 60 m inland. Wave surge to 180-200 m inland. Littoral
vegetation extensively damaged to 60 m inland. Sand accretion behind the vegetation
area.
(20) West Point Villas
Waves overtopped a 2 ft berm. Coral debris and sand thrown 300-350 m inland.
(21) Roxburgh Public Bathing Beach
Erosion to 5 m inland. Rock debris thrown to 50 m inland, plus some sand. Plant
debris thrown to 90 m inland.
Highest waves estimated at 6 ft.
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...Hurricane Gilbert...
(22) Priory Public Bathing Beach
Erosion to 15 m. Sand deposited at the back of the beach. Wave surge to 120 m.
(23) Western shoreline of Priory
Erosion to 50 m. Wave surge to 70 m inland. Littoral vegetation completely
destroyed, plus 10% loss of coconuts.
(24) Peter's Point
Extensive erosion to 20 m inland. Coral debris thrown to 50 m and plant debris to
60 m. Littoral vegetation damaged by wind and wave action.
Accumulation of coral debris on the reef.
(25) Salem
Severe erosion. Wave surge to 110 m.
(26) Club Caribbean
Total erosion of eastern beach; sand pushed inland. Wave height estimated by local
observers as 30 ft at the reef and 10 ft at the poolside.
(27) Silver Spring Hotel
Slight erosion of beach. Extensive damage to littoral vegetation.
(28) Jamaica Jamaica Hotel
Slight erosion up to 50 rn inland. Sand accreted to back beach.
(29) Jack Tar Hotel
Partial erosion, exposing coralline rock foundation of beach.
(30) Ambiance Jamaica Hotel
Severe erosion of beach. Wave height estimated by local observer at 30 ft
seawardside of reef and 7 ft at 65 m inland.
(31) Pear Tree Bottom
90% loss of littoral vegetation. Coral and plant debris thrown across the main road
and into the wetland.
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CEP Technical Report No. 4
Accumulation of debris on the reef.
(32) Puerto Seco Bathina Beach
Slight erosion.
(33) Bengal - Queen's Highway
Erosion to 60 m. Wave surge to 150 m. Debris removed from the shore and thrown
120 m inland. Almost total destruction of the littoral vegetation, including seaside
almond, sea grape and seaside mahoe.
(34) Bengal - Rio Bueno
Slight erosion to 12 m. Wave surge to 25 m. Slight wind damage to the littoral
vegetation.
Massive sediment load producing discoloration in the bay.
(d) Memorandum: J. Taylor, P. Campbell, E. Foster, 26.09.88
(35) Burwood Public Beach
Small net sand accretion.
(36) Seabord Street Fishing Beach
Beach severely eroded.
(37) Half Moon Bay Public Beach
Little damage evident to beach; whereas mangrove forest adjacent to Swamp Safari
completely defoliated.
(38) Flamingo Beach
Reef system "exposed" by much fresh debris extending about 20 m seaward.
(39) Ironshore/King Arthurs
Fresh accumulation of reef debris.
(40) Sunset Public Beach
Sand accretion evident.
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...Hurricane Gilbert...
(41) Club Paradise
Sand accretion evident.
(42) Doctor's Cave Beach
No beach erosion evident.
(e) Memorandum: J. Miller, 26.09.88
Bull Bay to Prospect Beach
(43) Bull Bay
Some erosion.
(44) Albion Beach
Mangrove defoliated ("burned").
(45) Rozelle Beach
Beach 75% destroyed, including the groynes.
(46) Lyssons Beach
Build up of sand about 1 ft high.
(f) Memorandum: A. Bailey, 27.09.88
(47) Western Kingston
No damage to the foreshore evident at the fishing beach beside the Causeway, Port
Henderson Fishing Beach or Fort Clarence Beach.
(g) Memorandum: O. Morgan, L. Gardner, 27.09.88
White River to Oracabessa
(48) Beach east of White River delta
Storm surge reached 100 m inland. Increase in beach debris.
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CEP Technical Report No. 4
(49) Sans Souci
Natural beach eroded approximately 25 M inland. Storm surge reached up to 180 m
inland.
(50) Tower Isle (Mr. Marsh-Dixon Property)
Beach eroded 55 m. Sand and debris deposited inland. Storm surge reached 90 m
inland.
(51) Couples Hotel
Beach eroded over entire 70 m width. Sand stacked inland against buildings. Littoral.
woodland suffered minimal damage. Much seaweed deposited on the beach.
(52)
Oracabessa
Extensive damage to entire shoreline.
(53) Golden Seas Hotel
Natural beach partially eroded; significant amount of debris and pebbles on the beach.
(54) Boscobel Beach
Beach severely eroded with approximately 90 9c loss of sand. Storm surge 70 m
inland.
(55) Plantation Inn
Beach severely eroded; some sand pushed to back of beach but most lost.
(56) Jamaica Inn
Beach eroded, but sand accumulated at back of beach and some quickly returned by
natural accretion.
(h) Memorandum; L. Gardner, 28.09.88
Gives the following estimates of costs resulting from the Hurricane -
JA$000's
Repair to change facilities on public beaches
2,410
Repairs to sea walls (6017,c damage
22,000
Repairs and replacement of groynes and jetties (8017,c damage)
16,000
Watershed rehabilitation
66,000
Page 72
...Hurricane Gilbert...
Rehabilitation of wetlands used as a nursery
7,000
Rehabilitation of severely eroded
500
Note: Reports damage to grqynes on the Palisadoes, Long Bay, Buff Bay and White Horses,
affecting stability of these beaches.
(i) Memorandum; D. Lee, 28.9.88
Storm surge varied between 50 ft and 100 yds along the south coast and 50 ft to 350 yds
along the north coast in areas visited. Both erosion and accretion were noted. Memorandum
suggests recommending set-back of infrastructures as part of the planning, for future
storms.
(j) Undated Summary Table
Table gives the following data on increase-s in silt load "deposits" in various rivers (see
Figure A7.1):
RIVER PERCENTAGE
Martha
Brae
River
5
Montego
River
5-7
Great
River
10
North west coast (Lucea East & West,
Davis Cover, Green Island Rivers)
15
Hope River (St. Andrew)
40
Morant
River
80
Plantain
Garden
River
80
Page 73
CEP Technical Report No. 4
Appendix 8
UWI SUB-AQUA CLUB SURVEY OF EXTENT OF DAMAGE AT OCHO
RIOS- MARINE PARK DUE TO HURRICANE GILBERT
USAC - University of the West Indies
Kingston, Jamaica
Participants: Ralph Robinson, Expedition Leader
Mona Lindo, Karen Roberts and Gillian Elliot
This preliminary survey was conducted on 18.12.88 along the two transects shown in
Figure A8.1.
Transect A
Access to the site was gained via the Americana Hotel. A fresh to strong breeze was
blowing, with many white horses in the fore reef area. Visibility in the back reef zone was
limited to less than 2 m. Due to these weather conditions and the apparent absence of a
negotiable channel leading to the fore reef, it was decided not to investigate the latter zone.
Rather, it was considered that safe access to the fore reef area is possible only by means of a
suitable boat.
As a safety precaution, we entered the water from the hotel beach with snorkelling gear
only, together with materials for recording observations. There was a strong 2-3 knot current in a
WSW direction in the back reef area. The bottom was composed mainly of large (5-10 cm)
stones, many of which were covered with algae. Three coral outcrops were investigated in a
straight line en route towards the reef crest. These were made up primarily of raised coral
limestone with suprisingly little encrusting algae. There was strong evidence of erosion of the
algal mat, particularly on the east and north portions of the outcrops. However, there was no
evidence of breakage of living coral; young, 10-20 cm, Millepora was observed intact, and
facing the general direction of the current.
Closer to the reef crest (25-35 m distant) there was evidence of small, dead coral fragments
strewn over the stony bottom. They became more plentiful towards the reef crest. It appears that
coral damaged prior to Gilbert had been broken from the exposed crest, and deposited in the
back reef area. The presence of living algae underneath some of these fragments suggested that
the coral debris had been recently deposited.
Transect B
Access to the site was gained via Carib Ocho Rios Hotel. A moderate breeze was present, and
the water in the back reef area was relatively calm. Visibility extended to about 15 m. There
appeared to be no easy access to the fore reef zone from our vantage point behind the
condominiums.
Page 74
...Hurricane Gilbert...
Figure A8.1 USAC dive transect locations
Page 75
CEP Technical Report No. 4
In contrast to Transect A, the back reef area on the eastern side of Mallard's Bay was sandy.
Large mats of seagrasses were evident, with coverage approaching 60%. Only a few small brain
corals were observed, occasionally with some attached fire coral at their bases, and these
appeared upright and intact. Deposition of old coral was equally marked, as in Transect A, and
extended some 35-40 m from the reef crest in to the back reef area.
The assistance of the Americana and Carib Ocho Rios Hotels is gratefully acknowledged.
C
Received: 12 January 1989
Page 76
...Hurricane Gilbert...
Appendix 9
THE EFFECTS OF HURRICANE GILBERT ON CORAL REEFS AT
DISCOVERY
BAY
By: Jeremy D. Woodle
Discovery Bay Marine Laboratory
Discovery Bay, St. Ann, Jamaica
Introduction
A hurricane is a violent environmental disturbance, tightly constrained in space and time.
Its "footprint" of extreme impact may be only a few score miles across, so that its track can be
represented by a line drawn on a map of the Caribbean. Wherever it strikes, it passes on with in a
matter of hours. To a human observer, it seems like a very rare, extreme event, unpredictable in
its occurrence and movement, highly localised, and contrasting sharply with a background of
more benign conditions. On a longer time-scale, however, hurricanes are common and
ubiquitous; a map of Caribbean tropical storms and hurricanes for the last hundred years is black
with their tracks (Neumann, et al., 1987). Thus, despite their small size and brief duration, any
point within the hurricane belt is subject to their influence. The temporal structure of that
influence depends upon the time scale of other processes affected by storms. Thus, in relation to
ecological processes of reef growth or sedimentation, on a time scale of hundreds or thousands of
years, hurricanes can be regarded as continuous force. On such a scale, it may be possible to
distinguish different intensities of that force due to differences in hurricane frequency in space
and time. On shorter time scales, the occurrence of hurricanes is irregular. Their influence on
processes measured on a time scale of the same order as the interval between hurricanes, such as
the generation time of living organisms, is better understood in terms of the time elapsed since
the previous storm.
This preamble will help in understanding the impact of Hurricane Gilbert on Jamaican
coral reefs. After Hurricane Charlie (1951), Jamaica enjoyed thirty years free from the impact of
large hurricane-generated waves. All kinds of corals flourished, but those which occupied space
by rapid growth were especially successful. Acropora palmata (elkhorn) and A. cervicornis
(staghorn) dominated large areas in extensive thickets. Rapid occupation of space was achieved
by a slender branching morphology; strong enough to resist routine wave energies, but fragile
under extreme conditions. In August 1980, Hurricane Allen passed close to the eastern and
northern shores of Jamaica and wrought catastrophic damage on their coral reefs (Woodley,
1980). Branching corals were smashed, some massive corals were toppled or shattered, softer
organisms like sea-fans and sponges were ripped up, and all were bombarded with fragments and
scoured by resuspended sand ( Woodley, et al., 1981). The recovery of reefs to their former
luxuriance had not occurred by September 1988, when Hurricane Gilbert struck. Thus, although
the physical impact of waves on the north coast was comparable to that of Hurricane Allen, the
damage to reef organisms was not as spectacular, because the time elapsed since the previous
hurricane was so short.
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CEP Technical Report No. 4
Injury to Reef Organisms near Discovery Bay
My own observations have been limited to the central north coast, and I will not speculate
about other areas. But at Discovery Bay, the reef condition is now approximately what it was
after Hurricane Allen. Massive corals on reef spurs that remained erect after Hurricane Allen (eg.
93% of Montastrea annularis at -10 m) mostly (97%) withstood Hurricane Gilbert. In reef
channels, survival was less good: 35% in 1980, 56% in 1988. Acropora cervicornis, which had
begun to recover at some locations, was completely smashed again. The rubble created by
Hurricane Allen (A. palmata slabs from 0-7 m, A. cervicornis sticks from 7-22 m) had become
cemented together by crustose calcareous algae and the process known as submarine cementation
(Land & Goreau, 1970). Under Hurricane Gilbert, the A. palmata slabs were re-mobilized,
scrubbed clean and re-distributed. So were the shallower stretches of A. cervicornis rubble;
cemented frameworks in deeper water remained intact, although scoured by sediment.
Remobilization of the rubble substratum had serious consequences for corals (and other
organisms) that had settled on it since 1980: opportunistic species such as Porites astreoides, P.
porites, Agaricia agaricites and Madracis mirabilis. Many sea-fans, sea-whips and sponges were
overthrown or broken, and piles of rotting corpses accumulated in channels and chutes on the
deeper fore-reef, especially at the sill that separates the fore-reef slope from the vertical deep
fore-reef at about -55m.
Physical Effects
Resuspended sediment, macerated tissues and terrestrial runoff greatly reduced
underwater visibility (and thus light penetration) after the storm, and it took a couple of weeks to
return to normal (visibility after two days, 3- m; three days, 6 m; four days, 10 m; nine days,
15 m). High organic loading in deposited sediments was evident for days or weeks in the
blackening due to sulphate reduction under the anaerobic conditions brought on by
decomposition.
The waves generated by Hurricane Gilbert may not have been as high as those of
Hurricane Allen, but their physically destructive impact underwater may have been greater,
judging from changes seen in reef structures and sediments. I attribute this to the difference
between the tracks of the two hurricanes. Hurricane Allen passed along the north coast, about
thirty miles offshore, rapidly moving West by North. At any point along the shore, the direction
of the incoming waves changed rapidly, and the period of maximum impact was brief (Kjerfve,
et al., 1986). Hurricane Gilbert came overland from Kingston on a track converging with the line
of the north coast. At Discovery Bay, hurricane force winds blew onshore for several hours from
an approximately consistent direction (North North-east), before veering as the storm passed by,
only a few miles to the south. Abrasive rubble and sediment were flung back and forth in the
same direction for hours. Linear scarification of the West Fore-reef at Discovery Bay is clearly
evident even now, three months later.
Quantities of sediment were removed from the reef terraces. Some was dumped onshore
as rubble ramparts or floods of sand, but most was carried downslope; not directly, but North
North-east, aligned with the major waves. At 20-25 m, therefore, reef lobes to the east of
channels suffered encroachment by sand. Sand clearly flowed down the fore-reef slope and some
Page 78
...Hurricane Gilbert...
of it will have passed through the intermittent chutes, off the terrace to the island slope below.
On the shallow terrace (3-15 m), small sand channels tributary to the major chutes, have been
swept clean. Hardgrounds, apparently representing a Pleistocene basement (L.S. Land, personal
communication), have been re-exposed.
At West Rio Bueno, a shallow terrace gives way to a vertical cliff at only -9 in. That
terrace supports dense reef growth between deep, narrow sand channels. Hurricane Gilbert
caused far more erosion here than did Hurricane Allen. Not only were the sand channels flushed
clean, but the sides of same channels were torn out, removing corals and revealing older reef
fabric. On the cliff itself, where Hurricane Allen caused little damage to plating corals at -10 and
-20 m, Hurricane Gilbert removed most of them (T.P. Hughes, personal communication).
Algae
Since 1983, when a natural epidemic almost eliminated the important herbivorous sea-
urchin Diadema antillarum (the long-spined black sea-egg; Lessios, 1984; Hughes, et al., 1985),
free-living algae have proliferated on Jamaican reefs (Liddell & Ohlhorst, 1986; Hughes, 1987).
Unrestrained by grazing (since herbivorous fish populations have been depleted by fishing),
these plants grew more quickly than corals and were out-competing them for space. Small corals
were smothered, and larger corals were being slowly overgrown from around their edges.
Hurricarne Gilbert scoured the reefs and removed most of this algal growth, giving a brief respite
from competition to the surviving corals. But algae were the first obvious colonisers of the bare
spaces created by the storm; a fine green turf in shallow water, and carpets of the red alga
Liagora throughout the terrace. The brown alga Dictvota also grew quickly in the first three
months.
Fish and Fishing
Immediately after the storm, individual fishes showed changes in behaviour similar to
those recorded after Hurricane Allen; loss of territories, unusual shoaling, behaviour. In the
longer term, Hurricane Gilbert, like Hurricane Allen, will have reduced the carrying capacity of
the reefs by reducing their three-dimensional complexity, although the change is less this time.
Some fishermen reported increased trap catches after the storm. This could have been due to
seasonal movements: to the fact that reef cover was reduced and traps offered more shelter, as
well as being more visible; and to the fact that the number of traps in use was greatly reduced.
Most fishermen had sufficient warning of the storm only to make their boats secure. Fishtraps
shallower than about -25 in were destroyed, while deeper ones were swept downslope to lodge at
the sill or drop over the edge.
Conclusion
Hurricane Gilbert was a very severe storm which generated waves of great destructive
power. They had a major impact on reefs of the central north coast, which would have been even
more catastrophic had not the damage already been done by the close passage of the equally
severe storm, Hurricane Allen, in 1980. As it is, Hurricane Gilbert has reset the clock of reef
recovery; they are now in a very similar condition to what they were after Allen.
Page 79
CEP Technical Report No. 4
References
Hughes, T.P. 1987. Herbivory on coral reefs: community structure following mass mortalities of
sea urchins. J. Expt. Mar. Biol. Ecol., 113; 39-59.
Hughes, T.P., Keller, B.D., Jackson, J.B.C. & Boyle, M.J. 1985. Mass mortality of the
echinoid Diadema antillarum Philippi in Jamaica. Bull. Mar. Science, 36; 377-384.
Kjerfve, B., Magill, K.E., Porter, J.W. & Woodley, J.D. 1986. Hindcasting of hurricane
characteristics and observed storm damage on a fringing reef, Jamaica, West Indies. J. Mar. Res.
44; 119 - 148.
Land, L.S. & Goreau, T.F. 1970. Submarine lithification of Jamaican reefs. J. Sediment.
Petrol., 40; 457-462.
Lessios, H.A., Robertson, D.R. & Cubit, J.D. 1984. Spread of Diadema mass mortality through
the Caribbean. Science, 226; 335-337.
Liddell, W.D. & Ohlhorst, S.L. 1986. Changes in benthic 6ommunity composition following
the mass mortality of Diadema at Jamaica. J. Expt. Mar. Biol. Ecol., 95; 271-278.
Neumann, C.J., Cry, C.W., Caso, E.L. & Jarvinen, B.R. 1978. Tropical cyclones of the North
Atlantic Ocean. NOAA, Washington, D.C.
Woodley, J.D. 1980. Hurricane Allen destroys Jamaican coral reefs. Nature (Lond.), 287; 387.
Woodley, J.D. and 19 others. 1981. Hurricane Allen's impact on Jamaican coral reefs. Science,
214; 749-755.
Received: 08 December 1988
Page 80
...Hurricane Gilbert...
Appendix 10.
EFFECTS OF HURRICANE GILBERT ON SELECTED OYSTER
CULTURE
SITES
By: Sandra Wright
Zoology Department
University of the West Indies, Kingston, Jamaica
(1) The Great Salt Pond/D'Aguilar's Pond, St. Catherine
The single bamboo and mangrove rack structure set up for experimental purposes in the
pond was undamaged. The strings of oysters became twisted among themselves, but the oysters
were undamaged. This suggests that wave action and swell were not excessive.
The surrounding mangrove trees were battered by the wind, but none of the trees were
uprooted and few of them lost more than their top branches.
The pond has a man-made entrance channel. This was undamaged and there appeared to be
no significant chancre to the profile or extent of the beach on either side of the channel mouth.
When the Pond was visited one week after the hurricane there was no visible difference in
the colour or clarity of the water from that observed during pre-hurricane sampling periods.
(2) Port Morant, St. Thomas
Many of the bamboo and mangrove rack structures were destroyed. All the bamboo rafts
sank or were washed away.
During the hurricane, strings of oyster spat collectors became twisted and coiled around the
rack structure supporting them. As a result of this, at low tide these strings were exposed for
unusually long periods of time. It was 2-3 days before anyone could get to the strings to unravel
them. By the time they were attended to about 60% of the spat had died (Information supplied by
Ministry of Agriculture staff). In the near future, this can be expected to have a serious adverse
effect on oyster production and the supply of spat to farmers.
There was no serious damage to mangrove trees in the area; and the stands of Rhizophora
supporting the natural oyster beds appeared not to have been damaged.
0
1:1
Loss of vegetation on the surrounding hillside could, in the long run, affect soil erosion,
which will increase sedimentation in the Bay. An increase in sedimentation could affect filtration
rates of the oysters and influence their growth and survival.
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CEP Technical Report No. 4
(3) Further note added on 03.01.89
Information obtained from the staff of the Ministry of Agriculture's Oyster Culture Project
on 3rd January 1989 indicated that a total of 14 rafts and 10 racks had been destroyed by
Hurricane Gilbert.
Received: 28 November 1988
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...Hurricane Gilbert...
Appendix 11
LIST OF PAPERS ON HURRICANE EFFECTS ON COASTAL AND
MARINE RESOURCE AREAS OF JAMAICA
Aiken, K.A., Bacon, P.P, & Mooyoung, R.R. (In press) Hurricane Gilbert and its effect on
Jamaican fishery resources. Proceedings 42nd Annual Gulf and Caribbean Fisheries Institute,
Ocho Rios, Jamaica, 5-10 November 1989.
Bacon, P.R 1989a. More on Hurricane Gilbert. World Birdwatch, 11(2); page 14.
Bacon, P.R. 1989b. Editorial. Neotropical Wetlands Newsletter, 4; 1-2.
Clark, J. 1988. Hurricane Gilbert assails Caribbean. ICBP Pan American Bulletin, 3(2); p. 2.
Eyre, L.A. 1968. Preciptation from Hurricane Flora, 1963. J. Tropical Geography, 26; 29-36.
Eyre, L.A. 1989. Hurricane Gilbert: Caribbean record-breaker. Weather, 44(4); 160-164.
Goreau, T.F. 1959. The coral reefs of Jamaica. 1. Species composition.and zonation. Ecology,
40; 67-90.
Goreau, T.F. 1964. Mass expulsion of zooxanthellae from Jamaican reef communities after
Hurricane Flora. Science, 145; 383 -386.
Graus, R.R., Macintyre, F.G. & Herchenroder, B.E. 1984. Environmental control of
Caribbean reef zonation Experiments in computer simulation. Advances in Reef Science:
Atlantic Reef Commission, R.S.MAS. Univ. Miami, joint meeting; 45-46.
Gray, C. 1988. History of tropical cyclones in Jamaica, 1886 to 19S6. National Meteorological
Service, Kingston, Jamaica; 23 pages.
Haynes-Sutton, A. 1988. Hurricane Gilbert strikes Jamaica's unique birdlife. World Bird-
watch, 10 (3-4); 1 & 11.
Hendry, M.D. 1979a. Historical evidence of shoreline evolution for the Palisadoes, Kingston,
Jamaica. Journal of Geological Society of Jamaica, 17.
Hendry, M.D. 1979b. A study of coastline evolution and sedimentology: the Palisadoes,
Kingston, Jamaica. Ph.D. Thesis, University of the West Indies, Mona, Jamaica; 225 pages.
Hendry, M.D. & Bacon, P.R. (In press) Effects of Hurricane Gilbert on the Jamaican coast,
with particular reference to damage and recovery of beaches. Proceedings 12th Caribbean -
Geological Congress, St. Croix, 7-11 August 1989.
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CEP Technical Report No. 4
Jones, E.B. 1986. Coastal vulnerability study of the Caribbean, Volume 3, Jamaica. Report to
the Pan-Caribbean Disaster Preparedness Project, Antigua.
Kjerfve, B., Magill, K.E., Porter, J.W. & Woodley, J.D. 1986. Hindcasting of hurricane
characteristics and observed storm damage on a fringing reef, Jamaica, West Indies. J. Marine
Research, 44; 119-148.
Knowlton, N., Lang, N.C., Rooney, PA., et al. 1981. Evidence for delayed mortality in hur-
ricane damaged Jamaican staghorn corals. Nature (Lond), 294; 251-252.
Liddell, W.D., Ohlhorst, S.L. & Boss, S.K. 1984. Community patterns on a Jamaica fringing
reef (1976-1983). Advances in Reef Science: Atlantic ReetCommission, R.S.MAS., Univ.
Miami, joint meeting 69-70.
Naughton, P.W. 1982. The Jamaica hurricane season - changing the rhyme. Caribbean J.
Science, 18; 107-111.
Naughton, P.W. 1984a. Storm surge risk problems for Kingston, Jamaica Revista Geográfica,
99; 93-97.
Naughton, P.W. 1984b. Flood and landslide damage-repair cost correlations for Kingston,
Jamaica. Caribbean Geography, 1(3); 198-202.
N.R.C.D. 1988. Hurricane Gilbert Impact Assessment Update and Plans for Conservation
Restructuring. Natural Resources Conservation Department, Ministry of Agriculture, Jamaica;
8 pages.
Ohlhorst, S.L. 1984. Spatial competition on a Jamaican coral reef. Advances in Reef Science:
Atlantic Reef Commission, R.S.MAS., Univ. Miami, joint meeting; 91-92.
Ohlhorst, S.L. & Liddell, W.D. 1981. Hurricane damage to Jamaican coral reefs. Geol. Soc.
Amer. Abstracts with program., 13; 522.
PCDPPP 1988. Lessons from recent events: Hurricane Gilbert. Caribbean Disaster News,
Double Issue 15 & 16, Sept./Dec. 1988; 20 pages.
P.I.J. 1988. Quarterly Economic Report, July-September 1988. Planning Institute of Jamaica,
5(2); 63 pages.
Porter, J.W., Woodley, J.D., Smith, G.J., Neigel, J.E., Battey, J.F. and Dallmeyer, D.G.
1981. Population trends among Jamaican reef corals. Nature, 294(5838); 249-250.
Ralph Fields Associates Inc. 1984. Summary of Proceedings of the Workshop on Storm Surge
and Wave Effects (Kingston Harbour Area), November 28, 1984. Report to the Office of
Disaster Preparedness and Emergency Relief Coordination, Kingston, Jamaica; 19 pages.
Page 84
...Hurricane Gilbert...
Rosesmythe, M.C. 1984. Growth and survival of sexually produced Acropora recruits: a post-
hurricane study at Discovery Bay. Advances in Reef Science: Atlantic Reef Commission,
R.S.MAS., Univ. Miami joint meeting; 105-106.
Scoffin, T.P. & Hendry, M.D. 1984. Shallow water sclerosponges on Jamaican coral reefs and
a criterion for recognition of hurricane deposits. Nature, 307; 278-279.
Seon, K. (Undated) Preliminary Disaster Catalogue - Jamaica 1559-1951. Office of Disaster
Preparedness, Kingston, Jamaica; 32 pages.
Tunnicliffe, V.J. 1983. Caribbean staghorn coral populations: pre-Hurricane Allen conditions at
Discovery Bay. Bull. Mar. Sci., 33(1); 132-151.
Williams, A.H. 1981. Effects of Hurricane Allen on back-reef populations of Discovery Bay,
Jamaica. J. Mar. Biol. Ecol., 77(3); 233- 244.
Woodley, J.D. 1980. Hurricane Allen destroys Jamaican coral reefs. Nature, 287; p. 387.
Woodley, J.D., and 19 others. 1981. Hurricane Allen's impact on Jamaican coral reefs.
Science, 214; 749-755.
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CEP Technical Report No. 4
CEP Technical Reports
1.
1989. The Action Plan for the Caribbean Environment Programme: Evaluation of its
Development and Achievements (1976-1987).
2.
1989.Regional Overview of Environmental Problems and Priorities Affecting, the Coastal
and Marine Resources of the Wider Caribbean.
3.
1989. Implications of Climatic Changes in the Wider Caribbean Region - Preliminary
Conclusions of the Task Team of Experts.
4.
1989. Assessment of the Economic Impacts of Hurricane Gilbert on Coastal and Marine
Resources in Jamaica.
Page 86