How new ideas could shape the future for oysters in the Bay

The University of Maryland Center for Environmental Science recognizes the value of oysters in the Bay and has a team of experts that focus their research on the benefits, health, and future of oysters in Chesapeake Bay. Keep reading below to learn about some of the key players in oyster research and their discoveries.

Removing nitrogen from the water

Jeff Cornwell

In 2013, Jeff Cornwell and a team of scientists discovered how much nitrogen is removed from the water by restored oyster reefs.

“Back when we had vastly more oysters in the 1970s, the Bay had ways to remove nitrogen that no longer exist,” said Cornwell, a research professor at Horn Point Laboratory. “We were able to determine that a square meter of restored oyster reef does 30 times as much as an unrestored area in terms of taking nitrogen out of the Bay.”

Restoring oyster reefs is critical to helping the Chesapeake Bay partners Total Maximum Daily Load (TMDL) requirements, a pollution diet set by the U.S. Environmental Protection Agency in 2010 to restore clean water in the Bay and its watershed.

Melanie Jackson

Graduate Research Assistant Melanie Jackson is working Cornwell to get a better understanding of just how much pollution oysters can remove.

Usually, she needs help from a team of divers that fills trays with sediment and oysters and places them on a restoration site for a month, and then retrieves them. That process takes a lot of time and people however, Jackson said.

“I’ve created a water sampling device where we have over 40 feet of tubing attached to a tripod that sits on the oyster reef. We can see how the water quality changes as the water flushes over the oysters, and we can see that there is nitrogen being removed over the reef.”

Listen as Jackson discusses her research on WHCP 101.5.

Rebuilding an empire of oysters

Hatchery Director Donald “Mutt” Meritt was working as a commercial waterman before he came to the University of Maryland Center for Environmental Science.

“The thing that I tell people is when I first got hired in 1973, I was very good at talking to oysters. Then after a while I realized they were talking back to me, and after a little bit more I started to understand what they were saying,” he said. “Oysters, like most animals or plants, will tell you when they’re happy, and they’ll tell you when they’re not.”

Meritt first came to the lab to work on a grant-funded project in the wake of Hurricane Agnes, which inundated the Mid-Atlantic region with heavy rainfall in the summer of 1972. With salinities at record lows, the Bay suffered major losses of oysters and soft clams. Over the years, the oyster culture facility and Meritt’s role there have grown.

As director, Meritt encourages his staff with a mantra: “Do it better this year than we did it last year, do it better next year than we do this year.”

Learn more about the oyster culture facility and read some of its success stories under Meritt’s leadership.

Unlocking new secrets through oyster genetics

Louis Plough

Louis Plough is a geneticist whose research is focused on marine animals, such as oysters and blue crabs, at Horn Point Laboratory. Recently, he has been working to develop a line of oysters that excels in low-salinity waters to support the growing aquaculture industry in Maryland.

Oysters typically grow well in high-salinity waters, but they are more prone to diseases that also thrive in higher salinities. Growing an oyster that excels in low salinity could lessen the potential impact of disease.

“I like to say we’re breeding around disease, spatially,” Plough said. “This is also a way to think differently about disease, not just do experiments people are already doing.”

His first step, is to measure the heritability of low-salinity tolerance and make sure he can reach his goal. Then he will identify genetic markers (e.g. genes) of low-salinity tolerance that can aid or accelerate breeding of a low-salinity line with his partners at the Virginia Institute of Marine Science’s Aquaculture Genetics and Breeding Technology Center. In the end, he hopes to provide for Maryland aquaculture farmers something they don’t readily have: more options.

Read more about Plough’s aquaculture project.

Graduate student Katie Hornick, who is working toward her Ph.D. under Plough’s guidance, is studying the population genetics of Eastern oyster restoration in Chesapeake Bay, with a specific focus on the Harris Creek sanctuary in the Choptank River.

Hatchery-produced oysters used for restoration may alter the genetic diversity of wild populations, but no one has monitored this at restoration sites in Chesapeake Bay. Hornick is using cutting-edge genetic tools to monitor potential changes to genetic diversity during the hatchery production cycle, and the diversity of the planted oysters in the years following planting.  

“If the genetic diversity is low, then they are not necessarily unhealthy, but if the oysters that we are planting, or the oyster populations in general, have a very high genetic diversity, then they will have better ability to withstand various environmental stressors that may come their way in the future,” Hornick said.

“It [diversity] is an important parameter to monitor because if you are stocking a population in the hopes of restoring it, it is important to make sure that it is healthy and will be there for generations to come,” she added. “It is a measure of population health.”

Imagining oysters' future in the Bay

Elizabeth North
Oyster restoration is a long-term project, and two scientists from the University of Maryland Center for Environmental Science, Elizabeth North of Horn Point Laboratory in Cambridge, and Michael Wilberg of Chesapeake Biological Laboratory in Solomons, have been focused on finding solutions that will enhance the shellfish resource and fishery going forward.
This effort is a five-year undertaking, called OysterFutures, and it pairs the scientists with watermen and other stakeholders with the hope of reaching a consensus on strategies for oyster fishing practices and restoration in the Choptank and Little Choptank rivers on Maryland’s Eastern Shore.
“The goal is to see if we can get this group of people with divers
e backgrounds and interests together on what should be done with oysters,” Wilberg said. “That’s what we’re trying to identify and short of that, we’re trying to identify things that can be done to make the situation better in everyone’s eyes.”
The oyster population that fell to less than 1 percent of population levels in the early 1800s due to overfishing, disease, and habitat loss.
“OysterFutures is trying to look at the fishery and figure out what kind of new approaches could be taken that integrate the fishing with restoration in a way that ensures the long-term health of the fishery as well as the resource, and hopefully bring less confrontation between the different communities that are surrounding the oyster,” North said.

Learn more about OysterFutures.

Measuring conditions for maximum benefits

Oysters have several ecological and commercial benefits, and increasing populations could maximize oysters’ impact in their local environment.

Matt Gray, an ecophysiologist at Horn Point Laboratory, has spent several years researching the ecological outcomes of restoration and aquaculture to better predict the valuable services provided by oyster species throughout the U.S.

“As these populations grow, so do their effects, which may eventually improve the entire ecosystem,” he said.

Gray’s research seeks to understanding the physiological responses of oyster to current environmental conditions and those predicted for the future and provide relevant information to help inform policy on restoration, fisheries, and the aquaculture industry in Maryland.