Biological and sedimentological samples were obtained in June 1980 from box cores taken in 100-200 meters of water on sandy-mud sediments near the East and West Flower Garden Bank (FGH) reefs, on the Texas-Loui siana Continental Shelf. The objective was to obtain needed and unknown baseline information about sedimentary parameters and organisms of the FGB environment to allow inferences to be made about the potential effects of physical disturbances of the seafloor on the indigenous benthos. Both microbial ATP and bacterial biomass are lower than reported for the Georgia Bight Shelf, Brazil-Amazon River Shelf, Cap Blanc, West African Shelf, western coast of Norway, and Long Island Sound. Bacterial counts are comparable to the Amazon River Shelf and lower than those recorded for the East China Sea. Moderate to low standing stocks of benthos further suggest that this area of the Gulf of Mexico is a relatively oligotrophic system for infaunal benthis consumers. (Copyright (c) 1985 Academic Press Inc. (London) Limited.)