Virginia has made significant investments in the restoration of oyster reefs in the Chesapeake Bay, and now a study led by the College of William & Mary’s Batten School and Virginia Institute of Marine Science suggests those management practices are literally paying off in the Rappahannock River.

The study, recently published in the “Journal of Environmental Management,” was led by W&M’s Batten School of Coastal & Marine Sciences Ph.D. student Alexandria Marquardt, who presented the results to the Virginia Marine Resources Commission’s Shellfish Management Advisory Committee last Wednesday, Feb. 19.

According to VIMS, in addition to supporting local economies, oysters filter the surrounding water removing algae and excess nutrients while clumping together to form large reefs that serve as habitat for many fish and marine animals. Though once abundant, oyster populations in the Chesapeake Bay collapsed in the mid-1980s due to a combination of overfishing and disease.

While VIMS has endeavored to increase wild oysters’ resistance to virulent pathogens, the VMRC regulates the fishery in Virginia and oversees efforts to restore oyster reefs.

The study showed that the density of juvenile oysters, known as spat, increased immediately following shell replenishment while the density of market-sized oysters peaked three years after, reinforcing the VMRC’s current three-year rotational harvest protocol.

Spat density, though highly variable, was highest in years coinciding with higher brown shell volumes, a measurement of reef health that refers to the number of oysters and shell above the bottom sediment layer. Marine protected areas were shown to have higher market oyster densities and offer protection from commercial fishing for larger oysters, which may provide a valuable spawning function for the fishery.

VMRC began its shell replenishment program in 2000 and implemented rotational harvests in 2007. These practices have resulted in steady increases in brown shell volume throughout the Rappa-hannock River and increased the likelihood of watermen meeting daily harvest limits.

Overall, the study showed that oyster harvests steadily increased with the improvement of the oyster reefs, with market oyster densities increasing substantially since 2018.

Since the 2007-2008 harvest season, more than 500,000 bushels of oysters valued at more than $24 million were harvested from the Rappahannock River. VMRC has invested more than $14 million toward replenishment in the river since 2000.