The chalk streams on the south coast of England are famous for their native salmon populations. Many of these rivers play host to adult salmon migrating from the marine to freshwater environment in the summer to spawn, and subsequent runs of juveniles (smolts) from freshwater out to sea in the spring to feed. These movements are heavily influenced by environmental variables including water discharge and temperature. However, as a result of climate change, increased periods of drought and rising air temperatures are predicted. Understanding how altered flow regimes and river temperatures associated with climate change will influence the migration of salmonids is a major challenge for their management and conservation. Human population growth and the consequential strain on water resources (e.g. increased levels of water abstraction) may also influence environmental variables in rivers and therefore salmon migration.

The aim of this research is to create a series of statistical models to analyse historic data and assess the influence of flow and other environmental variables on the migration of Atlantic salmon in UK chalk rivers. A series of predictive modelling techniques will then be used to estimate the size and timing of future salmon runs in accordance with climate projections.

The project is joint-funded by the Engineering Physical Sciences Research Council (EPSRC) and Southern Water.

People:

Nicholas Wilding

Prof. Paul Kemp

Dr. Derek Clarke