Geographic and temporal variation in the trophic ecology of a small-bodied shark: evidence of resilience to environmental change

Munroe, Samantha E.M., Heupel, Michelle R., Fisk, Aaron T., and Simpfendorfer, Colin A. (2015) Geographic and temporal variation in the trophic ecology of a small-bodied shark: evidence of resilience to environmental change. Canadian Journal of Fisheries and Aquatic Sciences, 72 (3). pp. 343-351.

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Abstract

Shark dietary patterns can determine how they will respond to changes in prey availability and biodiversity. Geographic variation in diet can also indicate if species have unique structuring roles or feeding strategies in different environments. Unfortunately, little is known about the diet of most shark species and how diet varies over time and space. This study used stable isotope analysis to assess the diet of the Australian sharpnose shark (Rhizoprionodon taylori). Plasma and muscle δ13C and δ15N of R. taylori were compared with δ13C and δ15N baselines from multiple embayments to determine the isotopic niche, trophic position, and benthic and pelagic contributions to diet over time and space. Overall, R. taylori had a wide trophic position range and consumed prey from benthic and pelagic sources. However, there was geographic and temporal variation in trophic position and benthic and pelagic contributions. These findings indicate R. taylori is a dietary generalist, but different populations may have unique effects on distinct ecosystems. Geographic variation in diet also suggests R. taylori may be adaptive to changes in prey availability.

Item ID: 43377
Item Type: Article (Research - C1)
ISSN: 1205-7533
Funders: National Environmental Research Program, AIMS@JCU, James Cook University (JCU), Great Barrier Reef Marine Park Authority (GBRMPA), Linnean Society of New South Wales (LS-NSW)
Projects and Grants: JCU School of Earth and Environmental Science, GBRMPA Science for Management Award, LS-NSW Joyce Vickery Scientific Research Fund
Date Deposited: 17 Mar 2016 03:21
FoR Codes: 06 BIOLOGICAL SCIENCES > 0602 Ecology > 060205 Marine and Estuarine Ecology (incl Marine Ichthyology) @ 75%
07 AGRICULTURAL AND VETERINARY SCIENCES > 0704 Fisheries Sciences > 070402 Aquatic Ecosystem Studies and Stock Assessment @ 25%
SEO Codes: 83 ANIMAL PRODUCTION AND ANIMAL PRIMARY PRODUCTS > 8302 Fisheries - Wild Caught > 830204 Wild Caught Fin Fish (excl. Tuna) @ 50%
96 ENVIRONMENT > 9605 Ecosystem Assessment and Management > 960507 Ecosystem Assessment and Management of Marine Environments @ 50%
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