Fish Prefer These Offshore Rigs

Fishing Rigs

Anglers know that oil and gas rigs mean fish, but a recent study investigated which types of platforms and water conditions were best for finding specific types of fish. Derek Bolser, a graduate student at the University of Texas Marine Science Institute (UTMSI), led one of the most extensive studies done-to-date, of individual fish species using these platforms. Some highly-prized species, like the red snapper, were more likely to be found around platforms with specific water conditions, but the big finding was that common species were found around platforms regardless of the water or type of platform.

Study On Rigs

In their study published yesterday in Marine and Coastal Fisheries, they present their findings from sampling 54 different oil platforms throughout the Gulf of Mexico in both nearshore and offshore habitats. Their study was unique because it encompassed such a large area with extensive sampling both at the surface and down along the platform to the bottom of the ocean. “We were able to expand upon the foundational work that described why fish were found on some platforms and not others and tested those things on a Gulf-wide scale,” Bolser said.

The study used a technologically advanced approach to collect data, combining specialized underwater cameras with instruments to measure water quality parameters to identify fish and water conditions every 10-meters. In their research, the scientists identified 17 of the most common species found on oil platforms and looked at how temperature, salinity, dissolved oxygen, and platform characteristics (like age, how many other platforms were nearby, and how many legs the platform had) affected the presence or depth location of fish. While there were some patterns explained for different species, many were likely to be found on platforms regardless of water conditions or platform characteristics

Researchers were able are able to account for, with confidence, why five of the identified species on the rigs congregated at different depths. With these set of fish, including greater amberjack, depth matters, and their relationship with the platform would adjust with changing temperature. Patterns related to distance from shore or how many other platforms were within five kilometers were also found in six species which may be related to their lifecycle or concentrations of prey around platforms. This detailed information of distribution patterns for species could be very important to fishery managers to help them understand and sustain fish populations as oil platforms and water conditions change and in establishing subsequent catch quotas.

Bolser and colleagues point out that despite the relative newness of oil platforms, just over the last 100-years, the species in the Gulf of Mexico were predisposed to take advantage of the structure. “The Gulf is a system of constant disturbance – hurricanes, hypoxic ‘Dead Zones’, and high heat. The fish here have evolved to handle changes in the water conditions, and they are programmed to congregate around structure,” says Bolser in explaining why many of the 17 species were found around platforms regardless of water conditions or platform type. Reef habitat and structure is a limiting factor in the Gulf of Mexico where rigs are present. “The platforms are where the food is and life happens. They aren’t willing to leave that despite how tough their living conditions get.”

This study was part of a larger project led by professor Brad Erisman and the Coastal Fisheries Research Program (CFRP) at UTMSI. Other coauthors include Tyler Loughran and Jack P. Egerton from CFRP/MSI; Arnaud Grüss at the University of Washington, Seattle; and Taylor Beyea and Kyle McCain at L.G.L. Ecological Research Associates Inc., Bryan, Texas.

Funding for this study and the larger project was provided by the Bureau of Ocean Energy Management and the Bureau of Safety and Environmental Enforcement. The Harrington Dissertation Fellowship from The University of Texas at Austin, the Texas Chapter of the American Fisheries Society and Sportsmen’s Club of Fort Worth’s Harry Tennison Scholarship, and the Coastal Conservation Association of Texas’s Allen Jacoby Memorial Scholarship provided additional support for this study.

Source: UTMSI