ITSASDRONE, an autonomous marine surface drone for fish monitoring around wave energy devices

Abstract

The ocean energy development is one of the main pillars of the EU Blue Growth strategy. However, while the technological development of devices is growing fast, their potential environmental effects are not well-known. The nascent status of the Marine Renewable Energy (MRE) sector and Wave Energy (WE) in particular, yields many unknowns about its potential environmental pressures and impacts, some of them still far from being completely understood. Wave Energy Converters’ (WECs) operation in the marine environment is still perceived by regulators and stakeholders as a risky activity, particularly for some groups of species and habitats. The SafeWAVE project aims to improve the knowledge on these impacts trough an Environmental Research Demonstration Strategy based on the collection, processing, modelling, analysis and sharing of environmental data collected in WE sites from different European countries where WECs are currently operating (Mutriku power plant and BIMEP in Spain, Aguçadoura in Portugal and SEMREV in France) representing different types of technology, different types of locations and different types of project scales, therefore, different types and/or magnitudes of environmental impacts. As part of SafeWAVE project, environmental monitoring plans relative to electromagnetic fields, acoustics (noise), seafloor integrity and fish communities need to be put in place. In the case of fish communities, generally speaking, any artefact located in the sea may cause an attraction effect on fish communities, especially if it is floating. In the case of Marine Renewable Energy Devices, during the operation phase, in general, the placement of any artefact in the sea can result in an attracting effect on fish communities, especially if it is floating. In order to study this possible effect, fish communities monitoring around the Penguin WEC-2 of WELLO-Oy localized in BiMEP test site with the ITSASDRONE surface drone developed by AZTI was planned. The study was designed to carry out the tunning and conditioning of the ITSASDRONE and to discover the associations between WECs and fish aggregations. Penguin WEC-2 of WELLO was removed from BiMEP test site due to an alarm of leakage. Consequently, we decided to carry out the monitoring work around the HarshLab, a floating laboratory device constructed by Tecnalia and localized also in BiMEP test site. The study allows us to validate the ITSASDRONE as a viable autonomous vehicle for fish school monitoring. It still needs some technological improvement related to navigation system, but in general, the ITSADRONE meets the objectives for which it was conceived and could be an excellent monitoring technique due to its capacity to work remotely and in near shore areas. Schools of unidentified small pelagic fish were observed distributed throughout the water column, predominantly near the bottom in the device area. But, future studies are needed to further explore the association between WECs and fish aggregations. The aim of this communication is to show the work done by an autonomous marine surface drone, ITSASDRONE, in relation to fish monitoring in BiMEP area.