MMSReefish Study Databases from 1993-1999 field collections (SEC7-95-11 Fish Mortalities From Explosive Removal of Petroleum Platforms)

Impacts of the Explosive Removal of Offshore Oil and Gas Structureson Fish Stocks in the Gulf of MexicoOffshore oil and gas platforms in the Gulf of Mexico (GOM) function as artificial reefs attracting a wide variety of marine life. Explosives are frequently used to remove these structures. These data describe the first comprehensive study to quantitatively assess impacts of the explosive removal of offshore oil and gas structures on fish. Between August 1993 and May 1999 surface and underwater sampling was conducted at nine explosive oil and gas platform removals in the GOM to estimate fish mortality. Water depth ranged from 14-36 m. After explosives were detonated, field personnel operating from inflatable boats used dip nets to collect all dead fish that floated to the surface while divers manually sampled dead fish that sank to the sea floor. The most severely impacted fish species at explosive structure removals in order of abundance were Atlantic spadefish (Chaetodipterus faber), blue runner (Caranx crysos), red snapper (Lutjanus campechanus), and sheepshead (Archosargus probatocephalus). These four species accounted for 86 of estimated mortality. Numbers of all other impacted species were far below those of the top four. Mortality estimates for red snapper were incorporated into stock assessment analyses. The impact of including explosive platform removal data was that abundance estimates were almost indistinguishable from the original assessment. The differences were well within the statistical estimation variances for the original assessment.