ACCESS NUMBER: 30951-70414 

STUDY TITLE: The fidelity of red snapper (Lutjanus campechanus) to petroleum 

platforms and artificial reefs in the northern Gulf of Mexico 

REPORT TITLE: Fidelity of red snapper (Lutjanus campechanus) to petroleum 

platforms and artificial reefs in the northern Gulf of Mexico 

CONTRACT NUMBER: 1435-01-99-CA-30951-70414 

SPONSORING OCS REGION: Gulf of Mexico 

APPLICABLE PLANNING AREA: Central Gulf of Mexico 

FISCAL YEARS OF PROJECT FUNDING: 2002-2004 

COMPLETION DATE OF REPORT: April 2006 

COSTS: FY 2002: $62,733; FY 2003: $26,784. FY 2004: $33,297 

CUMULATIVE PROJECT COST: $122,814 

PROJECT MANAGER: Charles A. Wilson 

AFFILIATION: Professor, Department of Oceanography and Coastal Studies, Louisiana 

State University 

ADDRESS: Louisiana State University School of the Coast and Environment, Coastal 

Fisheries Institute, Baton Rouge, LA 70803 

PRINCIPAL INVESTIGATOR: Charles A. Wilson 

KEY WORDS: Central Gulf; Louisiana; red snapper, rigs to reefs, biology; habitat; 

telemetry, site fidelity, migration 

BACKGROUND: The habitat value of petroleum platforms for red snapper, Lutjanus 

campechanus, is poorly understood. However, it is widely recognized by both scientists 

and fishermen that the presence of platforms in the northern Gulf of Mexico (GOM) has 

affected the distribution of red snapper by the addition of hard substrate habitat. 

Studies have shown that there is high diversity and biomass of fishes around platforms 

compared to the community that would normally inhabit sandy and muddy substrate if 

platforms were not present. 

Federal and international law requires the removal of all decommissioned platforms to 

minimize hazards to navigation. Over time, this removal of platforms could result in loss 

of recreational and commercial fishing opportunities. Some of these retired platforms 

have been converted into artificial reefs to preserve their habitat value. Although 

artificial reefs are viewed as a useful fisheries management and enhancement tool, not 
ACCESS NUMBER: 30951-70414 

enough is known about the life history and stock structure of fishes that use these 

habitats to address specific management objectives with artificial reefs. 

Acoustic telemetry can be used to obtain fishery independent data collection of fish 

presence/absence. Continuous acoustic tracking of red snapper is here used to 

investigate diel movements, habitat use, and site residence times. 

OBJECTIVES: The objectives of this study were: 

1. To develop a protocol for at sea surgical implantation of acoustic transmitters into 

red snapper. 

2. To use acoustic telemetry to investigate the short- and long-term site fidelity of 

red snapper to petroleum platforms and artificial reefs on the OCS of the GOM 

off the coast of Louisiana, thereby evaluating the habitat value of these platforms. 

3. To determine if uniform directional movement is undertaken by red snapper 

departing from the study area. 

4. To estimate fishing mortality on the red snapper population. 

5. To determine if any diel movement patterns are exhibited by red snapper around 

petroleum platforms and artificial reefs. 

DESCRIPTION: The study area was a 35-km2 portion of the South Timbalier oil and 

gas lease blocks (128, 134, 135, 151, and 152), 50 km south of Port Fourchon, LA. 

This area was chosen due to the close proximity of 12 standing platforms and numerous 

artificial reefs in a circle configuration, and the high frequency with which commercial 

and recreational fishermen visit the area. The closest platforms to the “circle rigs” are 

approximately eight km to the east in the South Timbalier 130 lease block. 

125 red snapper were captured by hook and line at the platforms. Following 

anaesthetization with MS-222, an individually coded acoustic pinger was surgically 

implanted into the peritoneal cavity of each fish. After a short recovery period the red 

snapper were released at five platforms in the study area. Presences of individual 

snapper were recorded with omnidirectional acoustic receivers attached to seven 

platforms, and to one artificial reef, a toppled platform. 

SIGNIFICANT CONCLUSIONS: Analysis of fish recapture and acoustic data revealed 

lower site fidelity and less uniform directional movement than shown by previous 

research on red snapper. The estimates of instantaneous fishing mortality were 

generally greater than the current value predicted by red snapper stock assessment. 

Red snapper at platforms exhibit diel movements away from the platforms during the 

night that may be explained by offsite foraging behavior. 

STUDY RESULTS: The mass tagging procedures developed in this study were 

extremely successful. It was possible to tag as many fish as could be captured by 10-

12 people fishing at all times. 
ACCESS NUMBER: 30951-70414 

Red snapper exhibited little movement between platforms in the study area. However, 

logistic regression showed a high initial fidelity to release location which subsequently 

decreased over time, thus site fidelity was found to be high in the short-term, but much 

lower in the long-term. Relocated fish showed no evidence of homing behavior to 

original capture locations. Red snapper recaptured outside of the study area showed 

little uniform directional movement. 

The results of the Fourier analysis and the LOESS procedure show that red snapper 

undergo a diel movement away from the receivers and platforms at night. The most 

likely explanation for the nocturnal movement away from the platform to feed on benthic 

organisms. 

Estimates of instantaneous fishing mortality on this population were higher than those 

predicted by the most recent stock assessment. The various combinations of natural 

mortality and tag reporting rates yielded a wide range of estimated instantaneous fishing 

mortality (F) values, ranging from 0.36 to 6.7. The most recent red snapper stock 

assessment panel report predicted a current F ranging between 0.292 and 0.474 and an 

MSY F ranging from 0.097 to 0.118, values much lower than any of the F estimates in 

this study. 

Some scientists believe that dense networks of reserves should be established as 

protection against management failure without assessing whether or not the reserves 

are likely to function as desired. Red snapper are not good candidates for marine 

reserves, as they are highly mobile and exhibit little long-term site fidelity; therefore 

management efforts should be focused on other methods. Knowledge of red snapper 

fidelity to petroleum platforms will lead to more effective management of this species by 

clarifying both the specific function of these structures as habitat and their importance to 

the red snapper population in the GOM. 

STUDY PRODUCTS: Peabody, M.B. and C.A. Wilson. 2003. The fidelity of red 

snapper (Lutjanus campechanus) to petroleum platforms and artificial reefs in the 

northern Gulf of Mexico. Poster Presentation. 56th Annual Meeting, Gulf and Caribbean 

Fisheries Institute. Tortola, British Virgin Islands, November 2003. 

Peabody, M.B. 2004. The fidelity of red snapper (Lutjanus campechanus) to petroleum 

platforms and artificial reefs in the northern Gulf Of Mexico. M.S. Thesis. Louisiana 

State University. Department of Oceanography and Coastal Sciences 

Peabody, M.B. and C.A. Wilson. 2006. Fidelity of red snapper (Lutjanus 

campechanus) to petroleum platforms and artificial reefs in the northern Gulf of Mexico: 

final report. Prepared by the Coastal Fisheries Institute, School of the Coast and 

Environment. Louisiana State University. U.S. Dept. of the Interior, Minerals 

Management Service, Gulf of Mexico OCS Region, New Orleans, LA. OCS Study MMS 

2006-005. 73 pp. 
ACCESS NUMBER: 30951-70414 

Figure 1. Map of study area. Circled area in main figure indicates the location where 

red snappers were tagged and released.