Using autonomous wideband echosounders to characterise polar ecosystems

Copepods and krill are ubiquitous in the world’s oceans. In pelagic food webs, they provide a key trophic link between primary producers and higher trophic levels, including commercial fisheries. They also play a central role in carbon cycling and export. Conventional acoustic methods have improved estimates of their biomass, and enabled novel insights into their behaviour. However, the identity of zooplankton targets often remains ambiguous: indeed, species identification is considered the ‘grand challenge’ for acoustic methods.

This challenge forms the basis for my project. Cutting-edge wideband echosounders offer the potential for improved target identification, by exploiting the characteristic frequency response of targets. An autonomous wideband echosounder deployed in Loch Etive, Scotland, will be used to develop methods for identification of Calanus finmarchicus, a key copepod in the North Atlantic and Arctic Oceans. I am also working with existing wideband acoustic datasets to develop a method for identification of Antarctic krill, Euphausia superba, combining a range of machine learning and modelling approaches.

Supervisors

Dr Kim Last (SAMS)

Professor Finlo Cottier (SAMS)

Dr Sophie Fielding (BAS)

Professor Andrew Brierley (St Andrews)

Funder

NEXUSS CDT (NERC/EPSRC)

University

University of the Highlands and Islands