University of Tasmania
Browse
137282 - No evidence for a decline in the density of Antarctic krill Euphausia superba Dana.pdf (942.42 kB)

No evidence for a decline in the density of Antarctic krill Euphausia superba Dana, 1850, in the Southwest Atlantic sector between 1976 and 2016

Download (942.42 kB)
journal contribution
posted on 2023-05-20, 10:40 authored by Cox, MJ, Candy, S, de la Mare, WK, Stephen Nicol, Kawaguchi, S, Gales, N

The Antarctic marine environment is changing, and changes in the Southwest Atlantic sector have included decreases in sea ice and increases in water temperature. Associated with these changes is a reported 38% and 81% per decade decline in the numerical density (hereafter density) of Antarctic krill Euphausia superbaDana, 1850, between 1976 and 2003. Few changes in other components of the ecosystem that could be attributed to such a change, such as a mass decline in krill-dependent predators, have been detected. In an ecosystem so dependent on this keystone species, a massive population decline in krill ought to have had an obvious effect. In the absence of such an effect, it is timely to revisit the issue of the purported decline in krill density. The original analysis that indicated a decline in krill density was based on the 2004 version of KRILLBASE, a database of net samples. We analysed the publicly available and updated version (version 1, accessed 30 November 2017) and our analyses did not suggest a significant decline in krill density. Rather, after accounting for sampling heterogeneity and habitat variables, average krill density appears to have been stable but with considerable inter-annual variability. Since our results were unable to find any evidence for a decline in krill density we recommend a re-appraisal of many of the paradigms that underlie much of the recent thinking about ecosystem change Antarctic waters. Such a revision is necessary to provide a firmer foundation for predictions of the effects of climate change and resource extraction on the Southern Ocean ecosystem.

History

Publication title

Journal of Crustacean Biology

Volume

38

Issue

6

Pagination

656-661

ISSN

0278-0372

Department/School

Institute for Marine and Antarctic Studies

Publisher

Crustacean Soc

Place of publication

840 East Mulberry, San Antonio, USA, Tx, 78212

Rights statement

Copyright The Authors(s) 2018. Licensed under Creative Commons Attribution 4.0 International (CC BY 4.0) http://creativecommons.org/licenses/by/4.0/

Repository Status

  • Open

Socio-economic Objectives

Wild caught crustaceans (excl. rock lobster and prawns)

Usage metrics

    University Of Tasmania

    Exports

    RefWorks
    BibTeX
    Ref. manager
    Endnote
    DataCite
    NLM
    DC