By Dylan Roberts, Head of GWCT Fisheries
A PhD completed by Sui Chang Phang at Bournemouth University and match-funded by the GWCT has successfully co-created an agent based model called ‘FishMORPH’.
This model simulates the individual behaviors and growth of brown trout and Atlantic salmon in rivers undergoing environmental change (e.g. climate change).
The model works by simulating the movements of the trout and salmon between different habitat ‘patches’ according to decisions based on optimal foraging theory, and predicts the ecological consequences of these movements.
The model predictions are accurate, as shown by very similar patterns in the fish behavior and growth rates between actual field data and model predictions.
The creation of this highly realistic model represents an important step for conservation and fishery management. For example, where the model predicts that low flows and elevated temperatures (as are predicted for rivers in Southern England in summer under most climate change projections) will have adverse impacts on the fish (e.g. larges decreases in growth rates), then actions can be taken now to help avoid these potential future impacts actually occurring.
These actions could range from increased abstraction controls to increase summer water flows through to increased tree shading of the river channel that can substantially decrease water temperatures. The model can also be used by fishery managers to develop an evidence based approach towards e.g. predator control and aquatic weed management in chalkstreams.
The model has now been published in Scientific Reports. The successful PhD student and lead author was Dr Sui Chian Phang (firstname.lastname@example.org), who is now a post-doctoral researcher at The Ohio State University, USA. BU co-authors and supervisors were Professors Rudy Gozlan (now at Institut de recherche pour le développement, France), Rob Britton and Richard Stillman. Dylan Roberts and Bill Beaumont were the GWCT collaborators, and Dr Julien Cucherousset (formerly BU, now CNRS and University of Toulouse, France) provided scientific advice throughout the research and manuscript writing.
Please support our Salmon Appeal
We're currently working on finding out why Atlantic salmon numbers have dropped by as much as 70% in some areas. Please give what you can afford so that our scientists can continue their vital work.