How volunteer gardeners along the bay are helping to revive oyster beds
Bayfront property owners are growing more than vegetables and flowers at home. Many have become oyster gardeners, helping to replenish diminishing and endangered oyster beds in Galveston Bay.
Last year, 83 oyster gardens — some with up to 20 “plots” — in San Leon, Kemah, Bayou Vista, Tiki Island and Galveston were part of the program.
Hurricane Harvey, which struck in late August last year, severely damaged the program’s efforts because of all the fresh water infiltrating the bays, according to the Galveston Bay Foundation, which has sponsored the program since 2011. Still, gardeners were able to see the potential for success, said Michael Niebuhr, program director at the foundation.
Each spring, volunteers are trained to create their oyster gardens by filling mesh bags with recycled oyster shells. They suspend the bags from piers and docks and drop them into the bay waters, where they are meant to attract oyster larvae during spawning season. The larvae, which is drawn to the shells, is called “spat.”
“All of the spat recruited by our gardens come naturally from the bay,” Niebuhr said. “During the spawning season, the amount of mature oysters in a given area will affect how much reproduction occurs and, therefore, how much free floating oyster larvae there is in the water, looking for a hard substrate to attach to — hopefully our shell bags.”
The home gardeners clean, measure and document information about the contents of the bags weekly. Shells must be rinsed off to eliminate any fouling algae and invading predators, such as crabs and oyster drills, which are snails that prey on new oyster growth.
Maureen Nolan-Wilde and her husband, Alan Wilde, both Master Naturalists, got involved in the program after working for several years focusing on the conservation of nesting bird habitat. They agreed to try five bags of shells to “grow” at their Tiki Island home, monitoring the growth of spat and other interesting predators in the bags. One of their bags was swept away during Harvey, but the other four produced a weight gain of 70 percent, from oyster spat as well as predatory mussels and other shellfish.
“For us, the experience was fun, educational and rewarding,” Nolan-Wilde said. “We were able to share the joy of gardening with our neighbors, as well as learning more about the plight of our oyster populations.”
Noland-Wilde set up a Facebook page to track her garden. She noted one neighbor was disappointed when she thought she had failed. But after a friendly “spat intervention party,” it was discovered that, in fact, she was successful and the oysters were busily growing.
“Fridays were the days we oyster gardened, and each week, we were always rewarded as we brought up our bags hanging off our dock,” she said. “It is amazing how oyster gardening can also bring a neighborhood together.”
In the fall and at the end of the spawning season, the bags are collected and taken to nearby restoration reefs and transplanted under the direction of the Texas Department of Parks & Wildlife, Niebuhr said.
“We keep all the new oysters in the same sub-bay system that they spawned,” Niebuhr said. “Currently, we use the reefs off the Kemah and San Leon shorelines and at Galveston Bay Foundation’s Sweetwater Nature Preserve in Galveston.” Because oysters are a colonial species, they rely on the accumulation of many to provide a stable environment for new growth.
The oysters, which reach adulthood in two years and can live up to 20 years, are collected and transplanted for restoration purposes only and not for consumption. However, in time, as the oysters mature in the reefs and begin to spawn, new oysters throughout the bay travel and repopulate other reefs, Niebuhr said.
Although oysters appear to be hardy creatures, they’re very sensitive to changes in temperatures as well as salinity of the waters. Until Harvey, the 2017 season looked to be on track for a record year.
“The enormous amount of freshwater sent into the bay almost resulted in 100 percent kill to some gardens,” Niebuhr said, adding that ultimately only about 1,000 new oysters were returned to the bay at the reefs.
Visit www.galvbay.org to learn about becoming a volunteer oyster gardener.