Application of a multibeam echosounder to document changes in animal movement and behaviour around a tidal turbine structure

Benjamin J Williamson* (Corresponding Author), Philippe Blondel, Laura D Williamson, Beth E Scott

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

14 Citations (Scopus)
12 Downloads (Pure)

Abstract

Changes in animal movement and behaviour at fine scales (tens of metres) in immediate proximity to tidal stream turbine structures are largely unknown and have implications for risks of animal collision with turbine blades. This study used upward-facing multibeam echosounder data to detect and track animal movement comprising fish, diving seabirds, and marine mammals. Measurements over spring-neap tidal cycles at a turbine structure (no blades present) are compared to a neighbouring reference area with no structure and comparable conditions, with measurements consecutive in time to maximize comparability.The majority of tracked animals (93.4\9.1\ were observed swimming against the flow, with 87.5\7.8\ respectively, making ground and showing capability of manoeuvring in tidal stream flow speeds. Track tortuosity increased around the turbine structure compared to the reference site, particularly in the wake and at low flow speeds, indicating animal station-holding or milling behaviour. These data also evidence the benefits of multibeam echosounders to measure animal movement through larger measurement volumes rather than relying on single-beam echosounders to measure animal presence alone, including to avoid large biases overestimating the size of schools swimming against the flow measured by time-in-beam.
Original languageEnglish
Pages (from-to)1253-1266
Number of pages14
JournalICES Journal of Marine Science
Volume78
Issue number4
Early online date28 Feb 2021
DOIs
Publication statusPublished - Aug 2021

Bibliographical note

Acknowledgements
We acknowledge the support of Shaun Fraser, Vladimir Nikora, James Waggitt, Paul Bell, Ian Davies, Eric Armstrong, and staff at Marine Scotland Science and the European Marine Energy Centre. Hydrodynamic model data were provided by Pierre Cazenave and Ricardo Torres (Plymouth Marine Laboratory). The constructive and extensive comments from three reviewers of an earlier version of this manuscript are gratefully acknowledged.
Funding
This work was funded by NERC and Defra (NE/J004308/1, NE/J004200/1, NE/J004332/1, NE/N01765X/1), a NERC MREKEP Internship, Innovate UK KTP (KTP009812), and the UK Department for Business, Energy and Industrial Strategy’s offshore energy Strategic Environmental Assessment programme.

Keywords

  • Environmental monitoring
  • marine renewable energy
  • tidal stream turbines
  • Fish behaviour

Fingerprint

Dive into the research topics of 'Application of a multibeam echosounder to document changes in animal movement and behaviour around a tidal turbine structure'. Together they form a unique fingerprint.

Cite this