Variable trends in the distribution of Atlantic cod (Gadus morhua) in the Celtic seas.

Autor: Ellis JV; School of Biological Sciences, University of Aberdeen, Aberdeen, UK., Schuchert P; Fisheries and Aquatic Ecosystems Branch, Agri-Food and Biosciences Institute, Belfast, UK., Scantlebury DM; School of Biological Sciences, Queen's University Belfast, Belfast, UK., Marshall CT; School of Biological Sciences, University of Aberdeen, Aberdeen, UK., Fernandes PG; School of Biological Sciences, University of Aberdeen, Aberdeen, UK.; The Lyell Centre, Heriot-Watt University, Edinburgh, UK.
Jazyk: angličtina
Zdroj: Journal of fish biology [J Fish Biol] 2024 Aug; Vol. 105 (2), pp. 512-525. Date of Electronic Publication: 2024 Mar 12.
DOI: 10.1111/jfb.15715
Abstrakt: Despite decades of active fisheries management, many stocks of Atlantic cod in its southern range are in a depleted state and mortality estimates remain high. Recovery of these stocks, as defined by management areas, could be confounded by cod distributions shifting outside of these areas. Here, we assess data from internationally coordinated trawl surveys to investigate the distribution of three cod stocks in the Celtic Seas ecoregion, Irish Sea, Celtic Sea, and West of Scotland, from 1985 to 2021. We mapped cod densities, analyzed trends in mean weighted depth and bottom temperature, and calculated the center of gravity and equivalent area of the stocks. The distribution of the West of Scotland stock shifted north and east, spilling into the North Sea, while the Irish Sea and Celtic Sea stocks shifted west. Each stock showed decreasing trends in equivalent area, but there were no clear trends in the average depth occupied by the fish. There was no apparent relationship between temperature and the distribution of cod, as bottom temperature varied little from 1993 to 2021. Although Irish Sea cod showed a shift into warmer water, this was due to changes in survey distribution. The shift in distribution of the West of Scotland cod stock towards the North Sea whilst impairing local recovery provides further justification for the recent definition of its incorporation into a larger stock unit that includes the northwest of the North Sea. The Irish Sea and Celtic Sea cod stocks are neither shifting northwards, nor into deeper waters, but remained within current boundaries. This suggests that recent temperature conditions did not affect their distribution, but this may change as temperatures increase towards the limit for reproduction.
(© 2024 The Authors. Journal of Fish Biology published by John Wiley & Sons Ltd on behalf of Fisheries Society of the British Isles.)
Databáze: MEDLINE
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