In just two hours on a Saturday afternoon, about 50 volunteers created roughly 200 oyster mats to be placed in Florida’s Indian River Lagoon as part of a restoration project that’s been ongoing for more than six years. The oyster reef restoration effort is led by Dr. Linda Walters, a biology professor at the University of Central Florida, located in Orlando. Walters and her colleagues created the program to help rebuild the oyster beds that were dying off at an alarming rate, having declined by more than 85 percent.
Oysters act as nature’s water filters, removing things like algae, bacteria and heavy metals from the water, improving the quality of the ecosystem. Oysters also help fight erosion and provide nourishment for a wide range of species.
According to Walters, the oysters were mostly dying off near the channels that transverse the watershed. Because Mosquito Lagoon and the Indian River Lagoon are microtidal areas, there is very little depth fluctuation. So, repeated boat wakes will cause clumps of oysters to break off and usually roll up on top of the oyster bed. These piles of broken-off oysters will pile up above the water line, causing the oysters to die. The reef can be lost completely over time, leaving nothing but mud where previously oysters and some 150 species thrived.
Natural factors have also contributed to the decline of the oysters. Things like storms, pollution, invasive species and disease will kill off oysters, but it’s the boat wakes that have been the one largest factor.
To repair the situation, Walters and her students rake down any oyster clumps they find and get them back under the surface. When they can, they also bring in an excavator to level out vast areas of oyster reefs. They also collect the dead oyster shells and put them to good use. Volunteers drill holes in the oyster shells and then connect them to a mat using a cable tie. There are 79 oysters placed on each mat. Once the volunteers build enough mats, they bring them back out to the lagoon and place them in areas where oysters were once located. Larval oysters, which float in the water, will attach themselves to the shells on the mats and begin to create new clusters.
The oyster mats are also being used to help fight erosion, especially around the Native American shell mounds. The oysters are placed below the tide line while grass is planted on the edge of the shore, as well as mangroves. Elementary students in nearby schools cultivate the grass and mangroves. Once the plants are large enough, the same youngsters will take a field trip out to the lagoon and plant them. According to Walters, the program has been a huge success. “We’re helping preserve the shell mounds and we’re also introducing a lot of young people to the local marine environment,” she said.
Since the program began, volunteers have made 26,000 oyster mats, each one with 79 oyster shells attached to it. Walters says that in 2.5 years there will be as many live oysters on the mat as shells. That’s more than 2 million new oysters!
So my wife, my mom and myself spent two hours on a Saturday helping out at the UCF Field House. There were students, volunteers and several members of the Coastal Conservation Association, who told me about the program. It was fun to do something to help preserve one of my favorite local fisheries.
For more information on the oyster reef restoration program and volunteering, contact Dr. Linda Walters at [email protected].