Variability in the Diet of Atlantic Croaker, Micropogonias undulatus, Sand Seatrout, Cynoscion arenarius, and Silver Seatrout, Cynoscion nothus in the Northern Gulf of Mexico

Wednesday, August 20, 2014: 9:00 AM
303B (Centre des congrès de Québec // Québec City Convention Centre)
Brittany Palm , University of New England, NOAA Fisheries, Pascagoula, MS
Gilmore Pellegrin , Missisipi Labs, NOAA Fisheries, Frederic Street, MS
In an effort to move towards ecosystem based management, predation data are now being used to construct food web models for trophic analyses. Food web models are largely structured by the body size of predators, the abundance of their prey in the natural environment, and quantifying predator-prey interactions. By incorporating stomach analysis on annual SEAMAP trawling surveys, predator-prey interactions can be monitored by identifying, enumerating, and quantifying food items consumed by key species. In a preliminary study, over 1,000 stomachs were collected and analyzed from three species of fish: Atlantic croaker (Micropogonias undulatus), sand seatrout (Cynoscion arenarius),  and silver seatrout (Cynoscion nothus) from the 2009 Summer and Fall SEAMAP-SEFSC  trawling surveys conducted in the northern Gulf of Mexico. Over 80 different prey types were identified and significant shifts in diet composition occurred by season and total length of predators. Atlantic croaker consumed more teleosts than previously reported and all three species preyed heavily on shrimp in the fall. Understanding the role these bycatch species play in the trophic ecology of the northern Gulf can provide important predator-prey interaction data that may be utilized for future management of the shrimp trawling industry.