Senior lecturer Dr Paul Kemp conducts international research in freshwater fish ecology and fisheries management. He is looking at behavioural attraction and repulsion and other aspects of fish behaviour, including distribution and routes of migration. Some fish, such as salmon and trout, exhibit avoidance of some hydrodynamic cues, such as acceleration of flow. This can reduce the number that may go down an abstraction point, for example into a turbine or other water supply off-take, but is negative when wanting fish to go down fish passes that also tend to have accelerating flows.

‘Fish ladders are not a new technology. There are records in 13th century England of a need to provide a space within weirs to allow salmon to reach upstream spawning grounds. What we really want to do,’ Kemp says, ‘is to tap into aspects of fish behaviour to manipulate their distribution and movement to increase the probability of deterring them from hazardous areas, such as turbine and water supply intakes, while diverting or attracting them to other preferred routes such as fish passes.’.

Work in this area has historically focused on salmon but has now broadened to include several species of fish that could be threatened by engineering work to modify rivers and control the flows of water. Research is underway around the world including China’s Yangtze River and the Amazon and scientists at Southampton use the flumes at the university’s science park to examine fish behaviour in response to hydrodynamics encountered at dams.

Another major area of Dr Kemp’s research concerns eels. The eel population has fallen by 90% over the past two decades and the species is now protected by EU legislation and the Convention on International Trade in Endangered Species of wild fauna and flora. Researchers at Southampton are investigating whether changing the lighting or acoustics near inlet pipes could encourage them to keep away.

‘Eels are slightly different and less sensitive to hydrodynamic cues than some other species of fish,’ Kemp explained. ‘Alternative approaches are needed for them. We are looking at the combined effects of different types of cues – hydrodynamics, acoustics and lights for example to increase the probability of inducing a desired response.’