The American Littoral Society hung bags of recycled oyster shells from docks on the Navesink and Shrewsbury rivers in June to see if they would attract oyster larvae. (Photo by John T. Ward. Click to enlarge)


After nearly three months, an effort to restore a once-thriving oyster ecosystem in the Navesink and Shrewsbury rivers has yet to detect the bivalve mollusk in the waterways, according to an update by the American Littoral Society.

“So far, the oyster wranglers have not identified any wild oysters on any of the shell bags” hung from local docks in an effort to attract free-floating larvae, the Sandy Hook-based organization  told its members in an email sent Monday.

“However, they have found an enormous variety of marine life inside and on the outside of the bags, such as fish, crabs, shrimp, and snails. This is giving us valuable insight into what is inhabiting our waters below the surface, including oyster predators.”

Among them: a host of foot-long American eels found as far up the Navesink as the Oyster Point Hotel.

“Very little is known about the migration patterns of that mysterious fish,” the society said in the email. “In our second round of sampling, we found a great many smaller specimens of that species.”

Starting in June, the society hung 195 nylon bags packed with recycled oyster shells off the docks of the hotel and riverfront homes whose owners had volunteered to participate in the project. The aim was to to attract oyster larvae, in the hopes that they would adhere to the shells and begin growing there.

From the email:

The bag checks did lead to identification of a number of oyster predators. Among them: oyster drills, oyster toad fish and mud crabs. Obviously we would rather find oysters than oyster predators, but it will be helpful to know what is in the river that might prey on oysters.
We cannot draw conclusions from the information gained so far, but as we continue to monitor into 2018 we should get a better picture of what now lives in the rivers and how that might affect the ongoing project.

Next month, the society plans to install a spat tank at the Rumson boat ramp so people from the community can learn more about the oyster life cycle. Next June, its members plan to seed the tank with oyster larvae, then hang bags carrying oyster spat in the river in order to monitor their growth.

“Eventually, if all goes well and we can get the appropriate permissions, we hope this work will lead to installation of an oyster reef,” the email said.

The waterways once teemed with oysters, providing nutritious food and a strong economic engine for the region for more than two centuries. Each bivalve is also capable of removing nutrients from 50 gallons of water a day.