“We have not recorded this extent of oyster spat recruitment in the fall survey in a generation,” Natural Resources Secretary Josh Kurtz said in a statement. “Both the quantity and the wide distribution of spat throughout the Bay, including several areas where our biologists have rarely observed spat in nearly 40 years of results, are outstanding.”
A number of factors are driving growth, the agency said, including higher-than-average salinity levels last year because of below-average rainfall in the watershed, making conditions better for oyster survival and spread. The agency also credited ongoing management efforts aimed at boosting the oyster population.
Less than 150 years ago, the Chesapeake Bay was laden with oysters, crabs and fish. By the end of the 19th century, an estimated 15 million bushels of oysters were harvested annually from the Maryland portion of the Chesapeake, according to the University of Maryland Center for Environmental Science. At roughly 100 oysters per bushel, that came to about 1.5 billion oysters each year.
But water pollution, disease and overharvesting in the 20th century savaged the once thriving ecosystem and the Free State’s oyster population collapsed. Oyster populations have suffered elsewhere as well. A team of global scientists estimated in a study published in the journal BioScience in 2011 that 85 percent of the world’s oyster reefs had been lost typically due to overharvesting, disease and environmental degradation.
It was not until the 1990s that state and federal governments in partnership with nonprofit environmental groups began concerted efforts to repopulate oysters in the Chesapeake.
The going, though, has been slow. Oysters remain at historically low levels and water quality remains a problem. A May report by the federal Chesapeake Bay Program found that in 2020 the share of the bay that met water quality standards was in the mid-30 percent range, not that much better than it was in the mid-1980s.
But there has been progress. The 2022-2023 season’s harvest was about 620,000 bushels of oysters — the highest total recorded in 35 years. And oyster repopulation efforts are flourishing in sanctuary areas in an attempt to build up oyster habitats and make the mollusks more resilient. Approximately 24 percent of oyster habitat in Maryland’s portion of the Chesapeake Bay is protected from harvesting.
The greater numbers and the growth of oyster reefs is a promising sign for bay health, officials said.
“Oysters are unique in that they are environmental engineers, meaning they create their own essential shell habitat as they grow,” said Christopher Judy, shellfish division director at the Department of Natural Resources. “This large influx of young oysters will help build a foundation for more oysters in the future.”
Oyster restoration is considered an essential part of returning the Chesapeake to health. Individual mature oysters filter gallons of water each day and consume algae, helping to remove excess nutrients from the bay. And it is important to the state’s economy as well, as oyster harvesting is second only to crabbing as an income generator for Maryland watermen.
Olivia Caretti, coastal restoration program manager for the Oyster Recovery Partnership, a Maryland nonprofit that works in partnership with state and federal agencies to help oversee oyster restoration projects in the Chesapeake Bay and its tributaries, said the results in the oyster survey are encouraging.
“It’s a really good sign for oysters,” Caretti said in an interview Wednesday. “Because there’s a lot of spat out there and because they’re distributed so broadly, that’s pretty significant. And hopefully that’s a good indication that the environmental conditions are really good for oysters right now.”
According to the 2023 survey, juvenile oysters were found in areas where they are rarely observed, including parts of Chesapeake Bay tributaries that in the past have been considered too brackish or otherwise not suited to significant oyster reproduction.
The department said the distribution of juvenile oysters far exceeded prior years and that findings in the Potomac River and two of its tributaries, the Wicomico River and Breton Bay, were at once-in-a-generation levels.
This year, the department reported finding spat at 50 of 53 key sampling sites for the survey, something that had not happened since 1985.
Maryland’s oyster restoration program is the biggest of its kind in the world, Caretti told The Post last year. Since it began its work in 1994, the Oyster Recovery Partnership has worked with Horn Point Lab at the University of Maryland Center for Environmental Science and the Maryland Department of Natural Resources to plant more than 10 billion oysters in reefs in the Chesapeake. By the end of last year, the total was expected to eclipse 12 billion.