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

Abstract

This review paper identifies the main effects of oil and gas drilling waste on benthic environments. We identified 26 papers and technical reports that surveyed sediment samples from 72 production or exploration platform sites to assess the zone of influence of sediment contamination and biological effects on benthic communities. While oil-based fluids are now rarely used in the marine context, their release has had large-scale (out to 6 km) and persistent (decadal time scale) impacts on benthic communities. The zone of influence of water-based drilling fluids as determined by sediment barium concentration was larger (2 to 20 km) than for synthetic-based fluids (200 to 2000 m). The zone of biological effects on benthic community diversity and abundance ranged from 100 to 1000 m for both water and synthetic fluids. Effects include changes in benthic species diversity, abundance and alterations to community structure. Functional changes included a loss of suspension-feeding species and increases in deposit feeders and polychaetes. In general, this review demonstrates a loss of benthic biodiversity and suspension-feeding communities due to oil exploration and production and the potential for large-scale effects on sensitive communities such as deep-sea, coral and vegetated habitats. Current research gaps and priorities are identified.