Effects of oilfield brine effluent on sediments and benthic organisms in Trinity Bay, Texas

Field studies have established the concentrations of naphthalenes in bay sediments and water in the vicinity of an oil separator platform and their effects on the benthic fauna. Fifteen stations were occupied monthly, from July, 1974 to December, 1975, along three transects extending from the separator platform outfall outwards for a distance of 4. 0 to 5. 6 km. A lesser number of stations were occupied from April, 1974 to June, 1974. Bottom sediments at each station were analyzed for total naphthalenes content and for number of species and individuals. All stations were located in 2 to 3m of water. The outfall was located 1m off the bay bottom. There was a definite correlation between sediment naphthalenes concentration and number of species and individuals. The bay bottom was almost completely devoid of organisms within 15m of the effluent outfall. Stations located 150m from the outfall had severely depressed benthic faunas but not to the extent of stations nearer the outfall. The temporary use of a second outfall located 275m from the main platform outfall resulted in a rapid build up of naphthalenes in surrounding sediments which persisted for at least six months following the termination of use of the second outfall. Refs