Siting and permitting/consenting tidal turbines and wave energy converters is a major challenge to the marine energy industry, as many people envision harm coming to marine animals. With many marine mammals holding endangered species status, this issue can adversely impact the public acceptance of marine renewable energy. Researchers in Scotland are developing methods to examine interactions, and to place the risk in a reasonable context. On May 19th, Annex IV, an initiative of IEA Ocean Energy Systems, held a webinar focused on current research in Scotland examining the interactions between marine and avian animals and marine energy devices.
Three Scottish researchers relayed their expertise in animal and energy device interactions, remarking on important roadblocks these issues might have for the industry.
Beth Scott, of the University of Aberdeen, reported on work by her students and colleagues on how tidal turbines might impact deep diving seabird populations. Seabirds may rely on specific ‘micro-habitats’ to forage; these micro-habitats of fast or slow moving water in a tidal channel could be disrupted by the installation of a tidal device. A study at the Fall of Warness, at the European Marine Energy Center in Orkney, UK performed transects with observers recording foraging seabirds in the tidal channel. Environmental variables were characterized in the same regions as each transect. The overlay of the foraging data with the environmental variables revealed differences between seasons and between species of foraging seabirds. These differences could be explained with different foraging techniques or prey availability. Ultimately, the study revealed factors that influence foraging distributions within tidal passes, which provides valuable information for understanding which foraging seabirds may be impacted by tidal devices.
Ben Wilson, of the Scottish Association for Marine Science (SAMS), presented an overview of ongoing research about the potential risk of marine mammal injury from a tidal device. He stressed that this is among the most pressing environmental issue facing the technology, as there is little existing data to create a robust assessment of risk. A marine mammal’s behavior around a tidal-stream device in place is largely unknown; the data gaps are being addressed with studies worldwide. Wilson recounted research on collision and acoustic risks, as well as potential displacement, barrier, and attraction impacts. Through these efforts, researchers worldwide are learning more about how marine mammals use high energy sites. The worldwide nature of Wilson’s presentation highlights the importance of Annex IV’s global effort to collect this data and remove barriers from the industry.
Benjamin Williamson, of the University of Aberdeen, showcased ongoing research using the FLOWBEC seabed platform’s instrumentation to identify interactions of birds, fish schools and marine mammals with marine energy devices. FLOWBEC (Flow, Water Column, and Benthic Ecology) is a monitoring tool for marine energy devices that has been deployed for 5 two-week segments at wave and tidal sites at the European Marine Energy Centre (EMEC). This project aimed to understand how currents, turbulence, and waves might impact marine life. Large marine life was identified with a multibeam sonar while simultaneously a multifrequency echosounder tracked measures of plankton and turbulence. An Acoustic Doppler Velocimeter provided concurrent current data. Williamson has developed techniques for filtering raw data into behavioral data that is synchronous with current and turbulence data. With this approach, marine life can be identified by species, leading to a more specialized understanding of how animals use high energy areas. The monitoring technology is scalable and appropriate for a range of monitoring applications. Moving forward, the technology will likely aid in predicting fish, marine mammals, and seabirds interactions with larger arrays.
This event was the second in a series of webinars spotlighting state of the art research aimed at understanding environmental impacts of ocean energy devices. The audio recording and more information from the first Annex IV webinar is available on Tethys: Annex IV Webinar #1. The full audio recording of the webinar and full abstracts of each presentation are available in the broadcasts tab. The next webinar will be held in late June and will focus on the environmental impact of energy removal from marine energy devices.