Why Farm Oysters in Texas?
There’s never a better time to get involved in cultivated oyster mariculture (COM) — that is, oyster farming — in Texas. The Gulf of Mexico produces 80 to 90 percent of oysters harvested in the United States, representing a huge chunk of the $2.2-billion industry, and Texas is just now joining the fray. In 2019, the Texas Legislature voted to allow COM, making Texas the last coastal state in the Gulf of Mexico to legalize off-bottom cultivated oyster farming. The Texas Parks and Wildlife Department (TPWD) developed rules governing the new industry in 2020. Now is a prime opportunity for Texans to jump into this new and lucrative shellfish industry.
How is Texas Suited for Oyster Mariculture?
Texas’s warm, nutrient-rich waters make the perfect environment for growing oysters. The green waters of Texas’s bays and estuaries provide an endless supply of food for growing oysters and help give them their unique flavors specific to the location where they are grown. Moreover, thanks to relatively constant warm waters and salinity, Texas oyster farmers can grow harvestable oysters in as little as one year. With seven major bays along the Texas coast, there is ample space for producing some of the largest, most flavorful oysters in the Gulf of Mexico.
Ecological Benefits of Oyster Farming
Oyster mariculture isn’t just an economic (and gastronomic) opportunity — it can also benefit the local ecosystem. Both wild and farmed oysters are water-cleaning powerhouses. A 3-inch oyster can filter up to 50 gallons of seawater per day as they feed. Their primary food sources are phytoplankton and tiny particles of algae. As they feed, oysters also take in excess nutrients, particles and organic material, virus and bacteria, biotoxins, and chemical contaminants, removing them from the water column. They also capture and store nitrogen, which is removed from the environment when oysters are harvested. Overall, these living filtration machines do a terrific job producing cleaner seawater and a healthier marine ecosystem.
Of course, you may wonder what happens to those toxins and pathogens when people eat oysters. It’s an important question and oyster farmers have to take precautions to make sure they produce the healthiest possible oysters for Texas diners.
What is off-bottom mariculture?
In the wild, oysters often grow in clumps attached to solid surfaces (such as rocks, shells, or piers). Over time, generations of oysters build up on top of each other to form huge formations of stuck-together shells, creating oyster reefs that provide rich habitats for a variety of sea life. In some parts of the country, oysters are harvested directly from the wild or produced in on-bottom farms that grow oysters along the seafloor, closely mimicking their natural habitat.
However, off-bottom mariculture, wherein oysters are grown in bags or cages floating or suspended near the water’s surface, is more common in the Gulf of Mexico and the only type of COM legal in Texas. Off-bottom techniques have several advantages that allow growers to produce more consistent crops of larger oysters that are ideal for the half-shell market:
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Positions oysters higher in the water column where their food (phytoplankton) are more plentiful;
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Allows farmers to control stocking density and biofouling; and
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Protects oysters from predators or hazards like being buried in sand/dirt.
About the Eastern Oyster
The only species of oyster farmed in Texas waters is the eastern oyster (scientific name Crassostrea virginica), the predominant farmed oyster species in the United States. In the wild, eastern oysters are found in shallow saltwater areas along the Gulf and Atlantic coasts from Canada to Mexico. Within that range are several unique genetic groups, so farmers must take care to select oysters from the correct geographic origins to avoid contaminating native populations (see our Biosecurity page for more information).
Oysters are filter feeders and herbivores, feeding on phytoplankton and tiny algae particles floating in the water column. In the wild, they form large groups attached to solid surfaces between 8 to 25 feet deep, but they are well suited for life in off-bottom cages or baskets that keep them in the nutrient-rich environment high in the water column. They are extremely adaptable to changing conditions, able to tolerate a range of water temperatures between 28 to 90°F and a wide range of salinities.
Eastern oysters reproduce sexually, with males and females spawning from late spring to early fall. Fertilized eggs transform into free-floating larvae, which eventually set on (attach to) solid surfaces and become juvenile oysters known as spat. Spat mature into oysters of about 1 inch in length in about three months, reaching market size of 3 inches in 18 to 20 months.
For more detailed information on eastern oysters, read Oyster 101.
Types of Oyster Farming Operations
Texas law permits three kinds of oyster farming operations: hatcheries, nurseries, and grow-out farms.
Grow-out operations raise oysters from seed (smaller than 1 inch) to harvest size (minimum 2.5 inches). Texas only allows off-bottom COM operations, which gives farmers three choices in farm setup: the Adjustable Long-Line System (ALS), floating bags, or floating cages. Choosing which system to use comes down to farmer preference and lease location.
Adjustable Long-Line System
Developed in southern Australia, ALS’s primary benefit is ease of use. Oyster baskets are attached to adjustable lines, which are suspended between PVC posts embedded into the bay floor. Farmers can raise and lower the lines simply by moving them up and down on the posts. For farmers who prefer not to use boats on their farm, ALS can be an excellent choice because the lines are managed while standing in the water. ALS makes hurricane preparation relatively easy because raising and lowering baskets is simpler and less labor intensive than the equivalent process in floating bag or cage systems. ALS baskets are smaller than floating cages and generally easier to tend. Moreover, it can be a good choice for shallow or rough intertidal areas where traditional harvesting methods would be too difficult.
However, ALS has its drawbacks. In the oyster industry, a location suitable for ALS is nicknamed “the Goldilocks lease”: the water cannot be too deep or too shallow, but has to be just right. Also, some farmers may prefer not to have to get into the water to work their lines – particularly on cold or stormy days – in which case ALS would not be the ideal choice. Furthermore, although the ALS infrastructure makes tending the farm easier, it also comes with significantly higher start-up costs and a longer installation period. And, of course, the more working parts involved in a system, the more chances there are for something to break in rough waters.
Floating Bags and Cages
Traditional off-bottom mariculture methods use floating bags and cages. Unlike ALS, floating systems can be set up in nearly any depth of water, so for farmers with deep-water leases, floating bags or cages may be the only options. Both systems come with lower start-up costs and less infrastructure installation than ALS operations, although farmers will need a boat big enough to carry gear but still maneuver between the bags/cages. If you prefer to work your lines from a boat, a floating system may be your preferred option.
The downsides to floating systems are what prompted the ALS’s inventors to come up with their alternative. Floating bags and cages are more labor intensive to maneuver, whether raising or lowering due to a storm or for routine maintenance and harvesting. They are also more prone to collecting floating debris.
Deciding between bags or cages
When choosing between floating bags or cages, each has its advantages. Bags are significantly less expensive and are smaller and easier to work with. However, cages can be a great option for a small lease because they can be layered vertically, allowing farmers to raise more oysters in the same amount of surface area; farmers should consider whether the potentially greater yield might make up for the higher start-up costs. In Texas’s choppy coastal waters, desiccation is also easier with cages, which, unlike bags, can be raised all the way out of the water and dried completely.
Ultimately, oyster farmers will find that location is the biggest factor when choosing a system and laying out the farm. Consider depth, debris, wave and tide patterns, and the most convenient way to access your lease. Keep in mind that the system you choose dictates farm orientation: ALS lines should be arranged perpendicular to the prevailing winds to maximize cage movement, whereas floating systems should be parallel to prevailing winds to minimize both debris collection and tension on the lines.
Permitting and Oversight for Mariculture in Texas
Cultivated mariculture operations in Texas are overseen by the Texas Parks & Wildlife Department (TPWD) The Texas Department of State Health Services (DSHS) governs shellfish sanitation rules. Oyster sales are regulated under both federal and state law.
Individuals planning to begin a mariculture operation must first get a permit from TPWD. The department offers two permit types, depending on type of operation: A Cultivated Oyster Mariculture Permit (COMP) is required for a nursery or grow-out facility, whereas a Broodstock Permit is required to set up a hatchery that will breed native oysters to produce seed to sell to nursery or grow-out facilities.
Additional permits are required to sell oysters from your permitted area: a Wholesale Fish Dealer’s License from TPWD and shellfish certification from DSHS.
See our permitting page for a step-by-step guide to the permitting process.
