Effects of gas-producing platforms on continental shelf macroepifauna in the northwestern Gulf of Mexico: abundance ans size structure

Macroepifaunal populations near three active natural gas-producing platforms were studied as part of the Gulf of Mexico Offshore Operations Monitoring Experiment (GOOMEX) using a nearfield (50-100 m) and farfield (3000 m) collection strategy. Differences were site specific, indicating that the epifauna responded to the unique physical and chemical characteristics of each platform. Differences declined with increasing depth, as did the frequency of significant seasonal and time-of-collection differences, suggesting that platforms affect adjacent community structure more strongly in shallow water. The significant differences occurred with equal frequency among mobile and less mobile species. Water column chemical anomalies, contaminant gradients and naturally occurring sedimentary chemical gradients were suspected as the forcing factors producing these biological trends between near- and far-field sites. 20 refs., 13 tabs., 2 figs