Benefits of Restoring Oyster Habitat

Oysters are hailed as “keystone” species vital to the ecological health of the Chesapeake Bay. The three-dimensional structure of restored oyster reefs supports hundreds of aquatic species and can dampen wave action along shorelines. Individual oysters filter 10 gallons of water per day, offering hope for cleaner water as the oyster population grows. Here is some background on ways restoring oyster habitat could affect Herring Bay.

Will restoring oysters in the sanctuary increase oyster populations?

Surveys of the oyster reefs being restored in Maryland’s sanctuaries, including Herring Bay, are showing promising results. The 2021 Oyster Monitoring Report on the sanctuaries in five major “tributaries” being restored in Maryland found that 100 percent of the reefs met or exceeded the minimum goals for oyster density after three years. Achieving those density goals correlated with an increase in oyster biomass.

Will restoring oysters in the sanctuary help local fisheries?

Oyster reefs that are off-limits to harvesting develop three-dimensional structures that provide food and refuge for other aquatic species. Studies of restored sanctuary reefs report increases in the abundance of crabs, perch-like fishes, toadfish, and other species of recreational and commercial interest. A 2022 study also found that there can be detectable increases in swimming fish and invertebrates in less than 10 years after restoration.

Will restoring oysters improve water quality in Herring Bay?

Oysters are known to remove nitrogen and phosphate pollution from the water. According to a recent report by the Chesapeake Bay Foundation, researchers estimate that “successfully restored reefs remove seven-times as much nitrogen—a primary water pollutant—each day when compared to unrestored areas.” While oysters’ filtration capacity improves the health of the Chesapeake Bay, it may be difficult to detect changes in the quality of the water in Herring Bay because of the effects of tides and currents and the scale of restored oyster beds relative to the size of Herring Bay as a whole.

Will restoring oysters adversely affect navigation?

No. DNR considers potential effects on navigation before approving a restoration site. To date, all restoration sites are in water that is at least 9 feet deep and an appropriate distance from dredged channels.

Can you anchor a boat on an oyster reef?

There are no restrictions on anchoring a boat on an oyster reef. Hitting the oysters with an anchor isn’t great for them, but apparently it’s not fatal.