Red Drum \u3ci\u3e(Sciaenops ocellatus)\u3c/i\u3e Trophic Web Reconstruction Using Stable Isotopes in Two Systems in the Northwestern Gulf of Mexico

Estuaries act as nurseries for many important fishes, including predators like Red Drum (Sciaenops ocellatus). Using gut content and stable isotope analyses to better understand juvenile S. ocellatus’ diet and role within the trophic web, a full year of data was collected on a quarterly basis to illustrate a change in diet based on resource availability at two study sites and for two non-overlapping S. ocellatus sizes. Panopeidae and Penaeidae were the most abundant prey items found in S. ocellatus stomachs for both sizes, sites, and four quarters representing over 50% of the diet. Stable isotope analyses from 80 fish show that S. ocellatus are feeding in very similar trophic levels but nonetheless there are significant differences for all quarters in δ15N between sites and δ13C between sizes, sites, and quarters. Differences may be linked to changing resources throughout the year, site composition differences, and seasonal changes in productivity