Seasonal δsup13/supC and δsup15/supN Isoscapes of Fish Populations along a Continental Shelf Trophic Gradient

Kara R. Radabaugh, David J. Hollander, Ernst B. Peebles

Research output: Contribution to journalArticlepeer-review

Abstract

<p> <p id="x-x-sp0055"> The West Florida Shelf, located in the eastern Gulf of Mexico, transitions from a eutrophic ecosystem dominated by the Mississippi River plume to mesotrophic and oligotrophic ecosystems off the coast of peninsular Florida. Three extensive trawl surveys in this region were used to acquire samples of fish muscle, benthic algae from sea urchin stomach contents, and filtered particulate organic matter (POM) to create &delta; <sup> 13 </sup> C and &delta; <sup> 15 </sup> N isoscapes. Muscle &delta; <sup> 15 </sup> N from three widely distributed fish species, <em> Synodus foetens </em> (inshore lizardfish), <em> Calamus proridens </em> (littlehead porgy), and <em> Syacium papillosum </em> (dusky flounder), exhibited strong longitudinal correlations (Pearson&prime;s <em> r </em> =&minus;0.67 to &minus;0.90, <em> p </em> &lt;0.001) that coincided with the principal trophic gradient, whereas &delta; <sup> 13 </sup> C values of fish muscle and benthic algae were correlated with depth (Pearson&prime;s <em> r </em> =&minus;0.34 to &minus;0.73, <em> p </em> &lt;0.05). Correlations between isotopic values and surface concentrations of chlorophyll and particulate organic carbon (POC) imply linkages between the isotopic baseline and transitions from eutrophic to oligotrophic waters. The &delta; <sup> 13 </sup> C depth gradient and the &delta; <sup> 15 </sup> N longitudinal gradient were consistent between seasons and years, providing a foundation for future stable isotope studies of animal migration in the Gulf of Mexico. </p></p>
Original languageAmerican English
JournalContinental Shelf Research
Volume68
DOIs
StatePublished - Jan 1 2013

Keywords

  • Stable isotope
  • C and N pathways
  • Isoscape
  • Marine food web
  • Animal migration

Disciplines

  • Life Sciences

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