ACCESS NUMBER: 30660-19960 

STUDY TITLE: Comparison of the Assemblage of Organisms at Two Artificial Reefs 

and a Production Platform in the Northern Gulf of Mexico 

REPORT TITLE: Rigs and Reefs: a Comparison of the Fish Communities at Two 

Artificial Reefs, a Production Platform, and a Natural Reef in the Northern Gulf of 

Mexico 

CONTRACT NUMBER(S): 30660-19960 

SPONSORING OCS REGION: Gulf of Mexico 

APPLICABLE PLANNING AREA(S): Central Gulf of Mexico 

FISCAL YEAR(S) OF PROJECT FUNDING: 1999 

COMPLETION DATE OF REPORT: June 2003 

COST(S): FY 1999: $158,036.06; CUMULATIVE PROJECT COST: $316,072.12 

PROJECT MANAGER: Charles A. Wilson 

AFFILIATION: Professor of Oceanography, Louisiana State University 

ADDRESS: Louisiana State University Coastal Fisheries Institute, Baton Rouge, LA 

70803 

PRINCIPAL INVESTIGATOR: Charles A. Wilson 

KEY WORDS: petroleum platform, hydroacoustics, northern Gulf of Mexico, artificial 

reef, natural reef 

BACKGROUND: Most of the natural substrate in the northern Gulf of Mexico (GOM) 

from Destin, Florida to Brownsville, Texas is silty with approximately 2800 km2 of 

naturally occurring hard bottom. During the last 60 years, the area of hard substrate in 

this region has increased through the development of infrastructure for a thriving oil and 

gas industry, creating the largest de facto artificial reef system in the world. These 

platforms not only increase the surface area of hard substrate available, but they 

arguably have a substantial impact on regional fisheries. The addition of petroleum 

platforms has doubtless affected many regional ecosystem processes such as energy 

(food) availability, habitat, recruitment, competition, and predation. 

In response to both the federally mandated removal of obsolete platforms, and to the 

popularity of petroleum platforms as fishing destinations, Louisiana, Texas, and other 

states along the northern GOM now convert retired oil and gas platforms into artificial 
ACCESS NUMBER: 30660-19960 

reefs. To date, these states have established over 170 artificial reefs from converted oil 

and gas platforms. 

The proximity of the two Rigs to Reefs projects and an operating oil and gas platform to 

the natural coral formations of the Flower Gardens (WFGB) afforded us the opportunity 

to not only compare several platform reef configurations, but also to compare the fish 

communities at "artificial reefs" to that of a neighboring natural system. 

OBJECTIVES: It was the purpose of this study to compare the fish communities 

associated with an operating oil and gas platform, two artificial reef configurations, and 

the West Flower Garden Banks (WFGB). Reef configurations included a production 

platform toppled in place as a deep water artificial reef (West Cameron 617A), a nearby 

partially removed platform (High Island A355), and an operating production platform 

(High Island A350). We sought to identify species composition at each site and to 

estimate the fish biomass/density associated with each site; to determine the effects of 

side, depth, and distance from each site on fish biomass. Comparisons were then made 

between these sites and to other sites that had been surveyed.

DESCRIPTION: Dual beam hydroacoustic surveys were used to estimate fish density 

and biomass at all sites. Survey design consisted of a stationary array of four 

transducers at the standing platform and mobile surveys at the remaining sites. The 

mobile survey of the two reefs sites consisted of multiple vessel passes over each 

structure and the mobile survey of WFGB consisted of twenty-seven transects spaced 

300 meters apart running along the long axis of the WFGB, from northeast to 

southwest. Visual surveys were conducted with a Deep Ocean Engineering Phantom 

HD2 ROV with standard visual census techniques recorded onto S-VHS video tape. 

SIGNIFICANT CONCLUSIONS: Overall, we found that fish biomass per cubic meter 

and density around the standing oil and gas platform were higher than the artificial reefs 

or natural reefs. Comparison of the mean biomass per cubic meter (Sv) found at the 

standing platform and over and immediately around the two reef sites and the WFGB 

terraces clearly indicate an order of magnitude difference between the standing platform 

and other sites, suggesting that standing platforms supported greater fish biomass per 

cubic meter. Our results are in support of previous findings that when a platform is 

converted into an artificial reef by toppling in place or by partial removal, it loses a 

significant portion of the fish community. Fish biomass per cubic meter at the artificial 

reef sites was similar to the upper terrace of the nearby natural reef. In each habitat, we 

tended to find higher fish densities in habitats with more vertical structure. 

STUDY RESULTS: This research continues to support the working hypothesis that 

platforms make useful artificial reefs since they tend to support a population of fish that 

can be 10 to over 1000 times greater in density than the adjacent sand and mud bottom 

habitats, and are equal to or even exceed that of natural hard reef-like habitat (WFGB). 

The species associated with the artificial reefs (including standing platforms) do 
ACCESS NUMBER: 30660-19960 

however, differ from those found on natural reef habitats. Future research efforts might 

be directed toward determining the reasons for this difference. Integration of these 

types of study results into a comprehensive spatial database will go far in improving 

management of these resources. 

STUDY PRODUCT(S): Wilson, C.A., A. Pierce, and M.W. Miller. 2003. Rigs and 

Reefs: a Comparison of the Fish Communities at Two Artificial Reefs, a Production 

Platform, and a Natural Reef in the Northern Gulf of Mexico. Prepared by the Coastal 

Fisheries Institute, School of the Coast and Environment. Louisiana State University. 

U.S. Dept. of the Interior, Minerals Mgmt. Service, Gulf of Mexico OCS Region, New 

Orleans, LA. OCS Study MMS 2003-009. 105 pp.

Pierce, Aaron. 2002. Do platforms make good artificial reefs? Comparison of fisheries 

value of standing, toppled, and partially removed platforms in the northern Gulf of 

Mexico M.S. Thesis Department of Oceanography and Coastal Sciences. Louisiana 

State University