Issue 18: Impact on biological and genetic diversity |
| Description |
|
Alien species can modify the composition of marine and freshwater communities and can have an increasingly significant influence on natural ecosystems. Invading alien species can cause complex changes within the structure and function of their new ecosystem. Impacts include restructuring established food webs, importing new diseases to the new surroundings, and competition with indigenous organisms for space and food. Other ecological changes may occur when the invading organisms reproduce with native species, possibly altering the gene pool. This may lead to hybridisation and homogeneity, which reduces biodiversity, the primary element associated with an ecosystem's adaptability to natural or human-induced changes. |
|
GIWA definition |
|
This issue refers to changes in biological or genetic diversity resulting from the introduction of alien species or sub-species as an intentional or unintentional result of human activity (e.g. aquaculture, restocking). It applies to all aquatic environments. |
|
Environmental impacts |
||
|
1. Changes in biological community structure due to overexploitation/depletion of one or more key species 2. Changes in biological communities through deliberate and accidental introductions 3. Changes in community structure by food chain manipulation 4. Changes in community structure through restocking and habitat manipulation 5. Increasing vulnerability of protected species populations 6. Changes to habitat and community structure resulting from destructive fishing practices 7. Ecosystem degradation 8. Long term changes in population genome and gene frequencies | ||
Indicators | |
|
The following are environmental impact indicators for impacts on biological and genetic diversity. Select the environmental impact indicators that are relevant from the list below and input data into the appropriate indicator sheets. | |
| SAT |
|
| BIO |
|
| EFF |
|
| SG |
|
| CR |
|