The effects of trawling and primary production on size-structured food webs in seabed ecosystems

Howarth, LM, Somerfield, PJ, Blanchard, JL, Waggitt, JJ, Allender, S and Hiddink, JG 2020 The effects of trawling and primary production on size-structured food webs in seabed ecosystems. Canadian Journal of Fisheries and Aquatic Sciences. 1-7.

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Understanding how different drivers shape relationships between abundance and body mass (size spectra) is important for understanding trophic and competitive interactions in food webs and for predicting the effects of human pressures. Here, we sample seabed communities from small polychaetes (<0.001 g) to large fish (>1 kg) in the Celtic Sea and the western English Channel to examine how bottom trawling and primary production affect their size spectra and to compare these with predictions from a model that couples predator and detritivore communities. Size spectra were not well approximated by linear fits because of truncation of the size spectra of detritivores. Low primary production resulted in lower abundance of benthic fauna. Bottom trawling reduced the abundance of predators and large detritivores but allowed small detritivores to increase in abundance. These empirical size spectra were partly consistent with predictions from the size spectra model, showing that understanding the structuring of benthic communities requires a consideration of both size and functional group. The findings highlight the need for an ecosystem approach to understanding the effects of exploitation and climate change on marine ecosystems.

Item Type: Publication - Article
Additional Information. Not used in RCUK Gateway to Research.: Corresponding author: Jan G. Hiddink (email:
Additional Keywords: Body size; bottom-up; top-down; bottom trawls; macroecology; size distribution; climate change
Divisions: Plymouth Marine Laboratory > National Capability categories > Single Centre NC - CLASS
Plymouth Marine Laboratory > National Capability categories > Western Channel Observatory
Plymouth Marine Laboratory > Science Areas > Marine Ecology and Biodiversity
Depositing User: S Hawkins
Date made live: 03 Sep 2020 13:11
Last Modified: 04 Feb 2021 11:50

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