Body condition of predatory fishes linked to the availability of sandeels
journal contribution
posted on 2023-05-18, 10:01authored byEngelhard, GH, Julia BlanchardJulia Blanchard, Pinnegar, JK, van der Kooij, J, Bell, ED, Mackinson, S, Righton, DA
Lesser sandeels Ammodytes marinus are eaten by a range of predatory fishes including commercially fished species, but are also exploited at large scale by industrial fisheries. Is availability of sandeels, as key prey source, linked to the body condition of predatory fishes? In the North Sea, the largest sandeel biomass is concentrated in the Dogger Bank region. Here we studied predator–sandeel interactions at two sites differing widely in sandeel abundance and local sandeel fishing effort. Surveys took place in 2004, 2005, and 2006, years when local sandeel densities observed at these sites were low, intermediate, and high, respectively. Five predator species––whiting, lesser weever, grey gurnard, plaice, and haddock––showed better body condition indices in either the years or study area (or both) characterised by higher local sandeel densities, when compared to sandeel-poorer conditions. Moreover, whiting, weever, and gurnard condition was better for those individuals actually observed to have eaten sandeels (based on stomach contents) than for those that had not. As body condition relates to growth, reproduction, and survival, predators in sandeel-rich conditions may be inferred to have a higher fitness. These links between sandeel availability, sandeel consumption, and predator condition hint that, if large-scale localised depletions of sandeels were to occur, negative indirect effects on predatory fish might become apparent, underlining the importance of considering the sandeel fishery in an ecosystem context.
History
Publication title
Marine Biology
Volume
160
Pagination
299-308
ISSN
0025-3162
Department/School
Institute for Marine and Antarctic Studies
Publisher
Springer-Verlag
Place of publication
175 Fifth Ave, New York, USA, Ny, 10010
Rights statement
Copyright 2012 Crown Copyright
Repository Status
Restricted
Socio-economic Objectives
Assessment and management of terrestrial ecosystems