Title: Trout stocking in SAC rivers. Phase 1: Review of stocking practice.
Author: Environment Agency
Document Type: Monograph
Annotation: Environment Agency Project ID:EAPRJOUT_1239, Representation ID: 404, Object ID: 2450
Abstract:
This report describes the first phase of a project to provide a decision-making framework for Environment Agency, English Nature and Countryside Council for Wales staff for the assessment of Section 30 consents to stock trout into candidate Special Area of Conservation (cSAC) rivers. A literature review and its interpretation is given along with the findings of an earlier report (APEM, 2002) to English Nature. Key potential ecological interactions between stocked brown and rainbow trout and cSAC species involve those with Atlantic salmon (competition from juvenile trout, predation by adult trout and, possibly, hybridisation between these species), white-clawed crayfish (possible disease transmission and predation by adult trout) and bullheads (predation by adult trout and, possibly, competition for resources). The selected rivers for study are briefly described on the basis of their cSAC designations. Information collected from riparian managers and from the Environment Agency Live Fish Movements Database is then given on recent trout stocking activity in these rivers. The key findings of this report are that trout stocking is relatively infrequent in six of the cSAC river systems studied (Eden, Yorkshire Derwent and Rye, Dove and Lathkill, Teifi, Wye and Usk). Because of this, important ecological interactions resulting from stocking are unlikely to occur except, possibly, via disease transmission (crayfish plague) to native crayfish populations. In order to reduce risks, close liaison between the Centre for Environment, Fisheries and Aquaculture Science (CEFAS, fish farm trout movements) and the Environment Agency, English Nature and Countryside Council for Wales (Section 30 consenting) is recommended. On the rivers Itchen and Hampshire Avon, relatively large numbers of trout are stocked into areas where Atlantic salmon spawn. In 2003, the Itchen salmon stock reached only 23 per cent of its conservation limit and the Hampshire Avon reached only 30 per cent. More research is needed to investigate whether trout stocking is likely to be a significant factor in depressing wild salmon abundance in these rivers. Initial analyses of trout catch records for the rivers Itchen, Nadder and Wylye show how catches relate to some extent to the timing of stocking and how trout fishery performance is finely regulated by managers. More information on typical trout residence times is needed.
Publisher: Environment Agency
Subject Keywords: Trout; Salmon; Salmon fisheries; Fishes; Stocking density; Predator prey relations; Disease transmission
Geographic Keywords: Eden (river, Cumbria); Derwent (Yorkshire); Rye (East Sussex); Dove catchment; Lathkill (Derbyshire); Wye catchment; Usk catchment; Itchen (Hampshire)
Taxonomic Keywords: Salmo trutta; Salmo salar
Extent: 81
Permalink: http://www.environmentdata.org/archive/ealit:4755
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