Effects of the nepheloid layer on biofouling communities occurring on coastal petroleum platforms in the northwestern Gulf of Mexico

Abstract

The Texas continental shelf in the Gulf of Mexico is a dynamic region influenced by winds, river, and offshore currents. The shelf is composed of terriginous sediment that contains varying amounts of silt and clay. There is a persistent bottom layer of turbid water, a nepheloid layer, which appears to be derived from both local resuspension of fine sediment and advection in the bottom boundary layer from coastal sources. Approximately 4000 petroleum production platforms are located in the Gulf of Mexico with many lying on the shelf where the nepheloid layer is persistent. Offshore platforms act as artificial reefs, providing critical habitat on large submerged surfaces for recruitment and settlement of larval sessile organisms. The biofouling community could be directly related to fisheries associated with platform structures. The purpose of this study is to determine significant differences caused from the presence of the nepheloid layer in the structure of biofouling communities on four Texas coastal petroleum platforms. Photographic transects and biomass samples will be used to describe the biofouling community. Data loggers will be used to record temperature and light attenuation parameters. Turbidity and physiochemical properties of water will be sampled in the vicinity of the data loggers. All data will be used to create a model associating turbidity with the biofouling community of Texas coastal platforms where a nepheloid layer is persistent for much of the year.