A new dynamic distribution model for Antarctic krill reveals interactions with their environment, predators, and the commercial fishery in the south Scotia Sea region

Freer, Jennifer J. ORCID: https://orcid.org/0000-0002-3947-9261; Warwick-Evans, Victoria ORCID: https://orcid.org/0000-0002-0583-5504; Skaret, Georg; Krafft, Bjørn A.; Fielding, Sophie ORCID: https://orcid.org/0000-0002-3152-4742; Trathan, Philip N. ORCID: https://orcid.org/0000-0001-6673-9930. 2025 A new dynamic distribution model for Antarctic krill reveals interactions with their environment, predators, and the commercial fishery in the south Scotia Sea region. Limnology and Oceanography. 17, pp. 10.1002/lno.12809

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Text (Open Access) © 2025 The Author(s). Limnology and Oceanography published by Wiley Periodicals LLC on behalf of Association for the Sciences of Limnology and Oceanography. Limnology Oceanography - 2025 - Freer - A new dynamic distribution model for Antarctic krill reveals interactions with.pdf - Published Version Available under License Creative Commons Attribution 4.0. Download (2MB) | Preview

Abstract/Summary

The management strategy for the Antarctic krill ( Euphausia superba ) fishery is being revised. A key aim is to spatially and temporally allocate catches in a manner that minimizes impacts to both the krill stock and dependent predators. This process requires spatial information on the distribution and abundance of krill, yet gaps exist for an important fishing area surrounding the South Orkney Islands in the south Scotia Sea. To fill this need, we create a dynamic distribution model for krill in this region. We used data from a spatially and temporally consistent acoustic survey (2011–2020) and year‐specific environmental covariates within a two‐part hurdle model. The model successfully captured observed spatial and temporal patterns in krill density. The covariates found to be most important included distance from shelf break, distance from summer sea ice extent, and salinity. The northern and eastern shelf edges of the South Orkney Islands were areas of consistently high krill density and displayed strong spatial overlap between intense fishing activity and foraging chinstrap penguins. High mean krill density was also linked to oceanographic features located within the Weddell Sea. Our data suggest that years in which these features were closer to the South Orkney shelf were also years of positive Southern Annular Mode and higher observed krill densities. Our findings highlight existing fishery–predator–prey overlap in the region and support the hypothesis that Weddell Sea oceanography may play a role in transporting krill into this region. These results will feed into the next phase of krill fisheries management assessment.

Item Type:	Publication - Article
Digital Object Identifier (DOI):	10.1002/lno.12809
ISSN:	0024-3590
Related URLs:	Dataset
Date made live:	03 Feb 2025 12:54 +0 (UTC)
URI:	https://nora.nerc.ac.uk/id/eprint/538848

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