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Abstracts
Session: Regional Updates
Gulf of Mexico: Status of Oyster Populations
Presented By:
Input for this presentation received from:
Lance Robinson, Texas Parks and Wildlife Commission
Martin Bourgeois, Louisiana Department of Wildlife and Fisheries
Scott Gordon, Mississippi Department of Marine Resources
Mark Van Hoose, Alabama Department of Conservation and Natural Resources
and Mark Berrigan, Florida Department of Agriculture and Consumer Services.
The eastern oyster, Crassostrea virginica, is distributed throughout the estuarine areas of the U.S. Gulf of Mexico. In some areas of the Gulf, oyster reefs are located in the states' territorial sea and even in the Gulf Exclusive Economic Zone (EEZ). Reefs are most abundant in shallow (under 40 feet) estuaries with salinities ranging from 5 to 20 ppt. Habitat is the most limiting factor controlling their abundance. This coupled with water quality and public health issues are this industry's greatest challenges.
Since oysters are primarily located in the estuarine areas of the states, they almost exclusively fall within the management jurisdiction of the individual states' natural resource agencies. For the Gulf these agencies are:
- Texas Parks and Wildlife Commission,
- Louisiana Wildlife and Fisheries Commission,
- Mississippi Department of Marine Resources
- Alabama Department of Conservation and Natural Resources, and
- Florida Fish and Wildlife Conservation Commission
Since these agencies are responsible for implementing rules, regulations, ordinances and/or statutes, they can and do have a dramatic effect on oyster management. Basic regulatory measures include, but are not limited to:
- Seasons,
- Daily bag limits,
- Size limits
- Gear restrictions,
- Harvest time restrictions,
- Leasing of water bottoms,
- Water quality monitoring,
- Data collection,
- Licensing and
- Enforcement
The Gulf of Mexico oyster fishery has a long and varied history. Production Gulfwide and statewide has fluctuated over time due primarily to habitat changes (including water quality) annually, seasonally and historically. In spite of this, Gulfwide oyster production has remained fairly stable and even increased in some geographic areas, unlike declining production in other areas of the county. Gulf production currently accounts for 59% of the oyster landings in the United States (during the period 1997-2001). This is up from approximately 36% for the period 1961-1965.
While Gulf production has remained fairly stable (with increases in some areas), the fishery is not without its problems. These include but are not limited to:
- Deterioration and loss of habitat (most serious).
- Development in estuarine areas.
- Modification of freshwater flow into estuaries for navigation, flood control and other purposes.
- Natural events (such as hurricanes and floods) and man-made activities (such as the removal of shells and cultch without returning sufficient amounts back to the reefs).
- Deteriorating water quality forces health agencies to close reefs when oysters become unsafe for human consumption.
- Oyster predators (drills - Thais haemastoma, stone crabs Menippe spp. , black drum - Pogonias cromis) , disease (Dermo - Perkinsus marinus), and harmful algae blooms, - (primarily Karenia brevis).
Data presented will include annual production figures by state, status of stocks by state, leased water bottom areas by state, public versus private lease production by state, factors affecting this production, and state activities relative to reef construction and rehabilitation, transplanting and relaying. Challenges facing the oyster resource, the industry and the management agencies will be discussed.
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