A novel approach to evaluate the effects of offshore energy infrastructure on the northern Gulf of America shrimp fleet

Abstract

ABSTRACT

Objective

The existence of offshore energy infrastructure in U.S. federal waters requires an understanding of how artificial structures impact regional fisheries. The Louisiana and Texas continental shelf in the northwestern Gulf of America (also known as the Gulf of Mexico) has a long history of offshore oil and natural gas development and harbors the penaeid shrimp fishery, the highest-valued commercial fishery in the region. Proposed wind energy areas (WEAs) on the shelf for offshore wind energy may disrupt this fishery due to spatial overlap with historical shrimping grounds and the fishery’s use of bottom trawls.

Methods

We used high-resolution spatiotemporal data on shrimp fishery effort developed from vessel monitoring data to investigate how development of proposed WEAs might affect the shrimp fleet. We quantified patterns of shrimp fishing effort at multiple spatiotemporal scales. We also investigated the attraction and avoidance response by shrimp vessels to existing oil and natural gas rigs to infer how future construction of fixed structures affects the spatial dynamics and behavior of the shrimp fleet.

Results

Less than 2.5% of the total annual shrimping effort between 2015 and 2019 occurred within the proposed WEAs in the region, and while rigs were generally avoided, shrimper trawling behavior was modified in certain regions due to spatial constrictions. The density of rigs largely controlled how closely shrimp vessels operated near platforms. In areas with high rig density, most effort occurred at distances nearly equal to the horizon, suggesting that line of sight was an important factor driving shrimper fishing behavior.

Conclusions

Further consideration of the responses of the fishing fleet to structures will enhance our understanding of how ocean development for multiple uses will affect regional bottom trawl fisheries and provide insight into the applicability of these methods for future marine spatial planning in and beyond this region.

Lay Summary

Offshore rigs affect the behavior of shrimp trawling vessels on the Louisiana–Texas continental shelf, with vessels generally avoiding rigs by modifying their trawling in areas with high rig densities. Understanding these responses can assist future marine planning to balance energy development and fisheries sustainability.