Impacts of Deep Oil Spills on Fish and Fisheries

Abstract

The Gulf of Mexico (GoM) total fishery production varies around one million metric tons per year. Fishery production is based on a diverse set of invertebrate and finfish species, including estuarine, continental shelf, and open-ocean species. The GoM has been subjected to two large oil spills in the Southern (Ixtoc 1, 1979–1980) and in the Northern GoM (Deepwater Horizon 2010) that caused serious concern about impacts on the abundance and seafood safety of fishery resources. Scientific evidence does not indicate a collapse or a clear impact on long-term fishery productivity related to either the Ixtoc 1 or DWH oil spills. Fishery landings in the Northern GoM returned quickly to pre-spill levels, and short-term declines could be attributed to the extensive fishery closure in the US exclusive economic zone. In the Southern GoM, fishery production post-Ixtoc 1 decreased dramatically over time attributed primarily to overharvesting of the main target species. Although no oil spill impact on the fishery resources was apparent at the population level, there is considerable evidence of impacts at the organismal and sub-individual levels, and there is concern how these effects could impact fishery resources in the long term. The responses of fish and shellfish populations are analyzed in relation to reproductive strategies, distribution of nursery grounds and critical habitats, exploitation status, oil spill distribution, and overall pollution levels. Fish and shellfish populations show a high capacity to withstand/recover from natural and anthropogenic impacts by taking advantage of favorable environmental conditions and by evolving life history strategies robust to seasonal and interannual variability. Stock resiliency is affected by several factors but mainly overharvesting that may reduce reproductive potential and compromise fishery resource resiliency in the eventual case of another large-scale oil spill disaster.