Restricting Fishing at Chesapeake Bay could Help Restore Oyster Population, Researchers Say

Limiting fishing at upper Chesapeake along with other methods to help oysters survive could bring back the oyster population in a short span of time, according to a new study.

The population of oysters in Chesapeake Bay has shrunk to just 1 percent of its original population, mostly due to decades of damage to the reefs, along with reduction in water salinity and diseases.

In the new study, researchers from University of Maryland Center looked at various oyster restoration strategies to see which ones could have a positive impact on oyster population.

"This new model we developed suggests that oysters should be able to come back if we help them out by reducing fishing pressure and improving their habitat," said Michael Wilberg of the University of Maryland Center for Environmental Science's Chesapeake Biological Laboratory, lead author of the study.

Restrictions on fishing along with leaving oysters in their natural habitat could help the oyster population bounce back. The study found that under favorable conditions, with a complete ban of fishing in the area, it would take about 50 to 100 years for the oyster population to reach its highest-ever record in the Bay. Cutting down fishing by 50 percent could take 200 to 500 years to restore the oyster population.

Oysters build their own habitat and support other organisms as well. Human activities such as chipping and breaking oyster shells leave the reef prone to damage. The new generation of oysters are thus scattered on the floor of the bay, which impairs their growth. Fishing removes adults from the population, and in turn removes the oysters' habitat. Researchers said that leaving oysters undisturbed in their natural environment could help them survive.

"The fishery as it has been practiced hasn't been sustainable, and our model helps explain why," said Wilberg in a news release. "Oysters just can't replace the shell that has been removed fast enough to keep up."

"Oysters should be able to rebuild their reefs if we leave them alone. It's an experiment that hasn't been tried yet," Wilberg concluded.

The study, "Sustainable exploitation and management of autogenic ecosystem engineers: application to oysters in Chesapeake Bay", is published in the journal Ecological Applications and can be read here.