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Terrestrial and marine trophic pathways support young-of-year growth in a nearshore Arctic fish

Polar Biology

By:
, , , and
DOI: 10.1007/s00300-012-1244-x

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Abstract

River discharge supplies nearshore communities with a terrestrial carbon source that is often reflected in invertebrate and fish consumers. Recent studies in the Beaufort Sea have documented widespread terrestrial carbon use among invertebrates, but only limited use among nearshore fish consumers. Here, we examine the carbon source and diet of rapidly growing young-of-year Arctic cisco (Coregonus autumnalis) using stable isotope values (δ13C and δ15N) from muscle and diet analysis (stomach contents) during a critical and previously unsampled life stage. Stable isotope values (δ15N and δ13C) may differentiate between terrestrial and marine sources and integrate over longer time frames (weeks). Diet analysis provides species-specific information, but only from recent foraging (days). Average δ13C for all individuals was −25.7 ‰, with the smallest individuals possessing significantly depleted δ13C values indicative of a stronger reliance of terrestrial carbon sources as compared to larger individuals. Average δ15N for all individuals was 10.4 ‰, with little variation among individuals. As fish length increased, the proportion of offshore Calanus prey and neritic Mysis prey increased. Rapid young-of-year growth in Arctic cisco appears to use terrestrial carbon sources obtained by consuming a mixture of neritic and offshore zooplankton. Shifts in the magnitude or phenology of river discharge and the delivery of terrestrial carbon may alter the ecology of nearshore fish consumers.

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Additional Publication Details

Publication type:
Article
Publication Subtype:
Journal Article
Title:
Terrestrial and marine trophic pathways support young-of-year growth in a nearshore Arctic fish
Series title:
Polar Biology
DOI:
10.1007/s00300-012-1244-x
Volume
36
Issue:
1
Year Published:
2013
Language:
English
Publisher:
Springer
Publisher location:
Amsterdam, Netherlands
Contributing office(s):
Alaska Science Center
Description:
10 p.
Larger Work Type:
Article
Larger Work Subtype:
Journal Article
Larger Work Title:
Polar Biology
First page:
137
Last page:
146
Other Geospatial:
Beaufort Sea