CENTRE FOR EVIDENCE-BASED CONSERVATION SYSTEMATIC REVIEW NO. 13 WORKING TITLE: WHAT ARE THE ECOSYSTEM EFFECTS OF SALMONID STOCKING IN LAKES ON NATIVE FISH POPULATIONS AND OTHER FAUNA AND FLORA?
Lake systems are often stocked with salmonid species to provide game fisheries. These fisheries have socio-economic value but concerns have been raised about the potential ecological impact of salmonid stocking (Aprahamian et al. 2003). The addition of a species high in the food chain can impact on...
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| Format: | Text |
| Language: | English |
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| Online Access: | http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.418.4837 http://www.environmentalevidence.org/Documents/Final protocols/Protocol13.pdf |
| Summary: | Lake systems are often stocked with salmonid species to provide game fisheries. These fisheries have socio-economic value but concerns have been raised about the potential ecological impact of salmonid stocking (Aprahamian et al. 2003). The addition of a species high in the food chain can impact on other organisms, which may have conservation value (Saura et al. 1990). Salmonids are usually considered a ‘low risk ’ species in this context, but further investigation is warranted, especially for ‘put-and-take ’ fisheries (i.e. stocking with catchable-size individuals) where fish density is often not closely connected to ecological carrying capacity. The impact of stocking on the abundance and species richness of non-stocked native fish species is the primary focus of the review. As wild fish populations continue to decline, fisheries managers are increasingly concerned about how hatchery and stocking operations might be contributing to declines of highly valued wild populations (Pearsons and Hopley 1999). Interbreeding between stocked and native fish populations is of interest as population viability may be affected (Youngson et al. 2003) and native species lost through hybridisation or being out-competed. 1 Secondary concerns include changes in the abundance or species richness of other fauna and flora including invertebrates, aquatic plants and plankton. The species used for stocking of relevance to the review are: Brown trout Salmo trutta Rainbow trout Oncorhynchus mykiss (there are many other Oncorhynchus species but they are not usually stocked in the UK) Atlantic salmon Salmo salar (landlocked forms) Arctic charr Salvelinus alpinus Brook charr Salvelinus fontinalis |
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