Combining biological and environmental survey techniques can further knowledge relating to species behavioural responses with marine energy technologies. Underwater video footage was integrated with ADCP surveys to assess behavioural responses of Pollack, Pollachius pollachius to a deployed tidal turbine in the Orkney Isles.
Surveys were conducted within 16 day trials during the summer months of 2009 and 2010. Five random photographic stills were taken at hourly intervals throughout each day to estimate mean fish abundance. Abundance was compared to hour and day temporal scales and ADCP tidal velocity rates between years. Fish were observed to aggregate in shoals round the turbine, with larger counts observed in 2009 than 2010. Abundance was significantly associated to tidal velocity and not temporal scales. Increased abundance was related to a reduction in tidal velocity for both years (from GAM2009: F= 38.31, p < 0.05; GAM2010: F= 4.45, p < 0.05), with shoals potentially using the turbine for temporary protection or feeding strategies. Responses to tidal velocity differed between years, with 2009 abundances ranging from 0 – 1.2 m/s and 2010 abundances between 0.5 – 1.7 m/s. Overall the study outlined a different approach to investigate behavioural responses with new anthropogenic activities.
Acknowledgement: This article was identified by the Crown Estate Wave and Tidal Knowledge Network