UNDERSTANDING MOVEMENTS, BARRIER PASSAGE AND HABITAT USE OF ANADROMOUS AND NON-ANADROMOUS TROUT IN NORTH NORFOLK
Collaborators: Environment Agency, Atlantic Salmon Trust, Wild Trout Trust, Norfolk Rivers Trust, Buxton Conservation Trust and University College London
The importance of salmonids originating from small streams for the wider European stock is poorly quantified, though growing evidence suggests that they make a significant contribution to the genetic diversity, and therefore resilience, of wider populations.
A telemetry study was conducted to quantify the origin, distribution, and migration characteristics of sea trout within North Norfolk rivers and associated coastal waters. Tracking of tagged individuals within freshwater and estuarine reaches will provide key information on fish movements, including: 1) temporal patterns of sea trout migration, 2) delay caused by structures, 3) migration rate, and 4) habitat use during freshwater and estuarine phases. Genetic and stable isotope analyses are being applied to determine the contribution of seatrout from small streams to the wider stocks.
Findings will provide regulatory authorities with the knowledge required for sustainable management of stocks, i.e. provide evidence for the Net Limitation Order, inform on the requirement for marine conservation zones, determine key spawning grounds, and identify barriers limiting migration.