At Water Street Oyster Bar in downtown Corpus Christi, oyster-loving diners encounter a variety of mouth-watering choices on the menu: oysters Rockefeller topped with greens and Parmesan cheese, grilled oysters filled with smoky paprika butter, and fried oysters dusted in cornmeal.

For many diners, even with all these delicious choices, nothing beats oysters in their purest form: on the half-shell. When the plate arrives, with shells arranged on a bed of ice, it's time to dig in. Loosen the oyster with the fork provided, bring the shell to your lips and let the oyster slide into your mouth.

You may not know it, but you're not just consuming a coastal food favorite — you're eating an ecosystem engineer. Oysters play an essential role along the Texas coast, filtering and cleaning water, providing habitat for other sea creatures and preventing erosion of the ocean floor.

These are tough times for oysters, which have faced declines over past decades because of hurricanes, flooding, droughts and high harvest levels. Last year, only eight out of Texas' 28 shellfish harvest areas were open. With the flooding seen this past spring, this year's Nov. 1 season opening will likely offer fewer wild oysters to harvest than industry, conservationists and consumers would like.

Essential Oysters

Oysters live in both salty and brackish waters in bays, clustering on older shells, rock, piers or any hard submerged surface. As they grow, they fuse together and create rock-like formations called oyster reefs, which are nestled on the bottom of the bay. As more oysters reproduce and settle on top of each other, the reefs continue to increase in size and change shape.

Oysters are highly resilient creatures, able to withstand harsh conditions for extended periods of time. But they are not invincible. Oysters represent one of the most imperiled estuarine habitats in the world. In the last century, the global oyster population has declined by 85 percent, and the population of the Gulf of Mexico by at least 50 percent.

Healthy oyster reefs and sustainable oyster populations are vital to the health and prosperity of the Gulf Coast. Oyster reefs are considered one of the most important habitats for improving resilience in bay ecosystems, and they provide myriad ecological services.

“Oysters are filter-feeders, which means they pump water into their bodies and filter out any particles they find,” says Lindsey Savage, restoration and artificial reef team lead for the Texas Parks and Wildlife Department's Coastal Fisheries Division, “This allows for the removal of sediment, excess organic matter and other pollutants from the water column, cleaning our bays. A single adult oyster can filter about 50 gallons of water a day!” In addition to oysters being experts at cleaning massive volumes of water, oyster reefs provide essential foraging and nursery habitat for numerous fish and marine species such as red drum, spotted seatrout, black drum and blue crabs.

Pressure on the Reefs

In recent times, oysters have been hammered, year after year, by water quality degradation, coastal development, destructive fishing practices, overfishing and storms. Our crown jewel, Galveston Bay, has been tarnished.

“In general, oyster abundances are highly variable from year to year, and impacted primarily by salinity, fishing pressure and disease,” says Zach Olsen, director of the Ecosystem Resources Program in TPWD's Coastal Fisheries Division. “Our routine oyster sampling data shows decreasing oyster trends in Galveston Bay over the last 20 years.”

Galveston Bay has been a national leader in oyster production in the United States. According to Olsen, the decline in oyster abundance in Galveston Bay has resulted in a shift in oyster fishing pressure to several mid-coast bays, including Aransas Bay and San Antonio Bay, which now, too, are feeling the effects.

“We have started to observe localized depletion in some of these mid-coast bays, which is exacerbated by heavy rainfall and flooding events, since flooding equals low salinity, which can result in large-scale oyster mortality,” Olsen explains.

With all these pressures on wild oyster reefs, TPWD periodically shuts down certain oyster harvest areas throughout the year to allow them to naturally recover. When wild oysters are fished, or harvested, both the shell and the oyster are removed from the water via a dredge, which is basically a big rake pulled behind a boat. Dredging can reduce the size and structural complexity of oyster reefs. Closing certain oyster harvest areas allows wild oysters time to repopulate and grow without fishing pressure.

TPWD carefully monitors wild oyster populations and closes reefs when market-sized oyster abundance drops below a threshold. This protects the vulnerable reef from damage and leaves more oysters in the water to grow to market size. Last year, 20 out of 28 shellfish harvest areas along the Texas coast were closed at the start of the public oyster season. Sack limits that once allowed 120 bags of oysters harvested per day have now been reduced to 30 bags per day.

Some areas identified as sensitive and valuable habitat, such as the Mesquite Bay Complex and Christmas Bay, have been closed on a long-term basis, Olsen says, to protect existing oyster reef habitat, supply juvenile oysters to adjacent areas and provide resilience to stressors such as disease and environmental extremes.

Farming Oysters

While the November oyster season may offer less-than-ideal wild oyster fishing prospects, a 2019 law has created a new industry for Texas oysters: cultivated oyster mariculture, or oyster farming. The Texas Legislature approved oyster farming in 2019, and TPWD adopted rules establishing the practice in 2020.

In Copano Bay, a northwestern extension of Aransas Bay west of Rockport, harvest practices, natural disasters and rises in sea level have depleted the wild oyster beds and all but eliminated the oyster fishing industry. That's why Lauren Dunlap, a resident of the area, founded Copano Oyster Company. Dunlap was among the first licensed oyster farmers in Texas.

Cultivated oyster mariculture offers an alternative oyster harvest method that does not rely on taking oysters from wild oyster reefs. Instead, oyster mariculture grows oysters in floating cages that are suspended near the water's surface. The “seed” oysters used in mariculture are produced in a hatchery. During this process, each oyster is set on an individual grain of sand. These baby oysters are then placed in the floating cages on oyster farms to grow to harvestable size; each farm can house thousands of oysters.

“There's a deep satisfaction in growing oysters from seed to harvest and knowing that my work supports healthier marine ecosystems,” Dunlap says. “Oyster farming is not only growing oysters; it's also about fostering a deeper connection to our environment. By choosing cultivated oysters, consumers can support sustainable practices and contribute to the health of our bays.”

According to Savage, “Oyster mariculture provides Texas oysters to consumers without harvesting from natural reefs and increases the overall number of oysters in our bays, which [also] gives us the water filtration benefits we know and love about oysters.”

Apart from playing a vital role in maintaining a healthy and thriving ecosystem, oysters are considered a delicacy around the world because of their distinct texture and taste. Since oysters are filter feeders, each oyster carries a unique flavor, reflecting the waters in which it was grown.

Variations in location, water column position, salinity and available nutrients all contribute to how an oyster tastes. For oyster enthusiasts, farmed oysters can provide a unique culinary experience, as distinct flavor profiles can be curated through specific cultivation techniques. Since cultivated oysters are grown in cages that are suspended closer to the water's surface, where more sunlight penetrates the water, there's more phytoplankton for oysters to eat, which produces a sweeter, more delicate taste.

“They have a great meat-to-shell ratio, the smell of the ocean, a buttery, rich texture and a nice savory salt tang but also undertones of green sweetness from the different types of phytoplankton they filter in the upper water column,” says Lindsay Glass Campbell, a biologist in the Coastal Fisheries Division, who oversees the permitting of commercial oyster mariculture in Texas.

Restoring the Wild Reefs

Despite the tough year for wild oysters, hope is not lost for our Texas reefs. TPWD is working hard to help restore Gulf oyster populations. In addition to closing off certain harvesting locations, the agency is also involved in restoring oyster reefs in areas that have become degraded to the point that there's no longer any hard substrate — live oysters, shell or otherwise — left to support larval oyster settlement.

Oyster restoration involves placing clean cultch material (recycled oyster shell, river rock, crushed limestone) into Texas bays to provide oyster larvae a hard surface to settle and grow upon. The cultch material is typically placed in degraded areas located near living reefs, giving the existing reef a “jump start” and allowing the reef building process to begin anew.

“To date, TPWD has restored more than 550 acres of oyster habitat in Texas bays,” Zach Olsen says. “We rely on historic and current maps of oyster reefs, oyster monitoring data as well as input from the oyster industry, academia and other stakeholders to inform our decisions on where to conduct oyster restoration.”

In addition, TPWD will also serve as the lead agency on a soon-to-be-awarded $8.2 million funded project for a large-scale, cutting-edge oyster restoration that aims to restore 20 to 50 acres of oyster reefs within the next six years. The project involves constructing new oyster reefs with large boulders that cannot be fished with dredges in areas that are conditionally open to harvest.

Through TPWD's implementation of the cultivated oyster mariculture program, management of wild oyster harvest and involvement in restoring oyster habitat, there's no denying that oysters are loved and respected by the Texas Parks and Wildlife Department, whose original name was the Texas Fish and Oyster Commission. With all that they do for the environment and its inhabitants, what's not to love about oysters?

Oyster Shell Recycling is Habitat Forming

15 Years of Sink Your Shucks

By Megan Radke

On an early summer evening, a coastal breeze cuts through the humid air at the dockside tables at Virginia's on the Bay in Port Aransas. Boats cruise in to the marina to dock after long days offshore as waiters deliver tray after tray of oysters on the half-shell.

But what happens once the shells have left the tables? In the Texas Coastal Bend, those shells aren't going to waste, thanks to the Sink Your Shucks Oyster Recycling Program, led by the Coastal Conservation and Restoration lab at the Harte Research Institute for Gulf of Mexico Studies (HRI) at Texas A&M University-Corpus Christi.

“The program founders recognized there was a resource out of place by putting oyster shells into the landfill, and they wanted to make a change,” says Natasha Breaux, a program manager in HRI's Coastal Conservation and Restoration lab. “By recycling the shell, we're able to eventually put them back in the bay, creating structure for baby oysters to settle upon and grow.”

Sink Your Shucks was started by HRI professor Jennifer Pollack and Corpus Christi restaurateur and oyster farmer Brad Lomax, among others. The program takes oyster shells that would have been thrown away and, after a quarantine period, bags the shells and strategically places them in local bays to create new habitat.

Now in its 15th year, Sink Your Shucks was the first in Texas to reclaim shells from restaurants and return them to local waters. In those years, more than 3 million pounds of shell have been collected, and more than 45 acres of oyster reef habitat have been restored throughout the Mission-Aransas Estuary in Copano, Aransas and St. Charles bays.

In May, 250 community volunteers — including local Rockport residents and a group of Coast Guard personnel from Sector Corpus Christi — helped to shovel, bag and build new habitat near the Goose Island State Park fishing pier.

“At first glance, we're an oyster recycling program, but that's not all we are,” says Mike Osier, HRI's Sink Your Shucks coordinator. “We spend the majority of our time doing outreach in the community and trying to get the word out about the need for this type of program, and about the loss of our oyster reefs. That work is something we can be proud of.”

Restaurants can learn how to partner with Sink Your Shucks, at no cost to them, by visiting SinkYourShucks.org.

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