Long-term changes in habitat and trophic level of Southern Ocean squid in relation to environmental conditions

Abreu, José; Phillips, Richard; Ceia, Filipe R.; Ireland, Louise ORCID: https://orcid.org/0000-0003-0960-0486; Paiva, Vitor H.; Xavier, José C.. 2020 Long-term changes in habitat and trophic level of Southern Ocean squid in relation to environmental conditions. Scientific Reports, 10, 15215. https://doi.org/10.1038/s41598-020-72103-6

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Official URL: https://www.nature.com/articles/s41598-020-72103-6

Abstract/Summary

Long-term studies of pelagic nekton in the Southern Ocean and their responses to ongoing environmental change are rare. Using stable isotope ratios measured in squid beaks recovered from diet samples of wandering albatrosses Diomedea exulans, we assessed decadal variation (from 1976 to 2016) in the habitat (δ13C) and trophic level (δ15N) of five important Southern Ocean squid species in relation to indices of environmental conditions—Southern Oscillation Index (SOI) and Southern Annular Mode (SAM). Based on δ13C values, corrected for the Suess effect, habitat had changed over the last 50 years for Taonius sp. B (Voss), Gonatus antarcticus, Galiteuthis glacialis and Histioteuthis atlantica but not Moroteuthopsis longimana. By comparison, mean δ15N values were similar across decades for all five species, suggesting minimal changes in trophic levels. Both SAM and SOI have increased in strength and frequency over the study period but, of the five species, only in Taonius sp. B (Voss) did these indices correlate with, δ13C and δ15N values, indicating direct relationships between environmental conditions, habitat and trophic level. The five cephalopod species therefore changed their habitats with changing environmental conditions over the last 50 years but maintained similar trophic levels. Hence, cephalopods are likely to remain important prey for top predators in Southern Ocean food webs, despite ongoing climate change.

Item Type:	Publication - Article
Digital Object Identifier (DOI):	https://doi.org/10.1038/s41598-020-72103-6
ISSN:	20452322
Additional Keywords:	Antarctic cephalopod; climate change; wandering albatross, Southern Ocean; trophic interactions, stable isotope analyses
Date made live:	22 Sep 2020 05:32 +0 (UTC)
URI:	https://nora.nerc.ac.uk/id/eprint/527556

Item Type:

Publication - Article

Digital Object Identifier (DOI):

https://doi.org/10.1038/s41598-020-72103-6

ISSN:

20452322

Additional Keywords:

Antarctic cephalopod; climate change; wandering albatross, Southern Ocean; trophic interactions, stable isotope analyses

Date made live:

22 Sep 2020 05:32 +0 (UTC)

URI:

https://nora.nerc.ac.uk/id/eprint/527556