Title

Non-parametric analysis of the spatio-temporal variability in the fatty-acid profiles among Greenland sharks

Document Type

Article

Publication Date

5-1-2018

Publication Title

Journal of the Marine Biological Association of the United Kingdom

Volume

98

Issue

3

First Page

627

Keywords

Ecological tracers, fatty acid signatures, polar ecology, predator diets, quantifying change

Last Page

633

Abstract

Shifting prey distributions due to global warming are expected to generate dramatic ecosystem-wide changes in trophic structure within Arctic marine ecosystems. Yet a relatively poor understanding of contemporary Arctic food webs makes it difficult to predict the consequences of such changes for Arctic predators. Doing so requires quantitative approaches that can track contemporary changes in predator diets through time, using accurate, well-defined methods. Here we use fatty acids (FA) to quantify differences in consumer diet using permutational multivariate analysis of variance tests that characterize spatial and temporal changes in consumer FA signatures. Specifically we explore differences in Greenland shark (Somniosus microcephalus) FA to differentiate their potential trophic role between Svalbard, Norway and Cumberland Sound, Canada. Greenland shark FA signatures revealed significant inter-annual differences, probably driven by varying seal and Greenland halibut responses to environmental conditions such as the NAO, bottom temperature, and annual sea-ice extent. Uncommon FA were also found to play an important role in driving spatial and temporal differences in Greenland shark FA profiles. Our statistical approach should facilitate quantification of changing consumer diets across a range of marine ecosystems.

DOI

10.1017/S002531541600148X

ISSN

00253154

E-ISSN

14697769

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