Fisheries impacts of underwater explosives used in platform salvage in the Gulf of Mexico

Abstract

The most severely impacted fish species in terms of highest numbers of estimated mortalities were
Atlantic spadefish, blue runner, red snapper, and sheepshead. These four species accounted for 86%
of estimated mortality. Of all species collected, the NMFS conducts stock assessments on only three:
red snapper, gag and red drum. For red snapper, even when the mortality estimate was doubled,
impacts were estimated to be small, well within the variation of our current assessments, and would
not alter current determinations of status or current management recovery strategies. Similarly,
current methods of assessment would not detect the even smaller changes in magnitude of gag and
red drum. In general, results indicated no significant difference in estimated mortality of red snapper
by depth, longitude, platform age, season, surface salinity, and surface temperature in the study area
(14–32 m) during May to September. Future impacts to the red snapper stock were predicted based
on forecasts of future structure removals reported by Pulsipher et al. (in press). Estimates of future
mortality were less than the doubled value of current red snapper mortality at explosive structure removals and within the variation of our current assessments. Given the assumptions used in these forecasts, predicted future mortality would not alter current determinations of status or current
management recovery strategies.