OSC are pleased to announce publication of the article Predictable changes in fish school characteristics due to a tidal turbine support structure in the peer-reviewed journal Renewable Energy. This manuscript was co-authored by our Research Analyst, Dr. Laura Williamson.
Due to uncertainty on ecological effects of tidal stream turbines, and their increasing prevalence, concerns have arisen about animal collision with turbine blades, disruption of migratory and foraging behaviour, attraction of animals to prey aggregating around turbines, or conversely, displacement of animals from preferred habitat. This study used concurrent ecological and physical measurements to show predictability of fish school characteristics (presence, school area, and height above seabed) in a high-energy tidal site across spring/neap, ebb/flood, and daily cycles, and how this changed around a turbine structure.
The rate of fish schools and school area per hour increased by 1.74 and 1.75 times respectively around a turbine structure, compared to observations under similar conditions without a structure. Largest schools occurred at peak flow speeds and vertical distribution of schools over the diel cycle was altered around the turbine structure.
While predictable attraction or aggregation of prey may increase prey availability and predator-foraging efficiency, attraction of predators has potential to increase animal collision risk. Predictable changes from the installation of turbine structures can be used to estimate cumulative effects on predators at a population level. This study can guide a strategic approach to the monitoring and management of turbines and arrays.
First author Dr. Benjamin Williamson is Lead Scientist for the ‘Renewable Energy and the Environment’ Research Theme at the Environmental Research Institute. Second author Dr. Shaun Fraser is at the North Atlantic Fisheries College (NAFC) Marine Centre in Shetland, and Professors Beth Scott and Vladimir Nikora are both at the University of Aberdeen. This new publication was founded upon previous work by the authors to build a sub-sea sensor platform to investigate environment and animal behaviour around tidal turbine structures.
Benjamin W., Fraser, S., Williamson, L., Nikora, V., Scott, B. (2019) Predictable changes in fish school characteristics due to a tidal turbine support structure. Renewable Energy, 141, 1092-1102.