Abstract
To assess adequately the impacts of offshore renewable energy installations (OREI) on marine fish abundance and diversity there is a burgeoning need to determine the movements, space use and spatial dynamics of commercially important species within and adjacent to OREIs.
Unique seabed lander technology housing data-logging acoustic receivers has been developed by the Marine Biological Association for long-term monitoring of fish movements in difficult-to-study offshore locations subject to significant current speeds and wave height.
The current project has succeeded in deploying six seabed landers to form an acoustic monitoring array around the Wave Hub site off Hayle in North Cornwall that is now capable of supporting long-term tracking of transmitter-tagged fish.
Over 140 fish including rays, plaice and sole have been tagged with acoustic transmitters or data-storage tags in the vicinity of the Wave Hub. Acoustic–tagged fish movements are being tracked automatically by the receiver array while data storage tags are returned when fish are caught through the fishery.
Early results show that rays exhibit short-term philopatry to localised inshore habitats adjacent to the Wave Hub that is interspersed with longer ranging movements to deeper offshore habitats where fishing pressure is higher.
The deliverables of the current project and that of the NERC QBEX project (2012-2014) will have put in place the required long-term fish and shellfish monitoring arrays/tags and developed the tools for analysis; the next step requires an extended period of consolidation of the data recording and analysis phases.