If the bay scallop fishery can be restored to places like Cape Cod and Long Island, the Vineyard may be able to take credit for it.
The Wampanoag Tribe of Gay Head (Aquinnah) is in the midst of a multi-year scientific experiment in Menemsha Pond that could have a wide-ranging impact on the future of bay scallops in the region.
The tribe is trying to find reasonable and attainable ways by which small communities can promote the raising of the bay scallop, a critically important local fishery. The Wampanoags are doing it with the help of a three-year $240,500 grant from the U.S. Fish and Wildlife Service.
Recently Bret Stearns, director of the tribe’s natural resource department, was out on the pond with Jessie Kanozak, coordinator of the bay scallop enhancement project. The two, who are overseeing the project, on this cold morning were dressed for underwater diving.
Their mission was to do a bottom survey of bay scallops in a closed area, a one-acre underwater garden. From April through October, Ms. Kanozak went below at least once a week to see how well the bivalves were doing.
Menemsha Pond is a perfect place to raise bay scallops. It is enclosed, has a good exchange of clean water from the ocean and plenty of food available in the water for shellfish. The history of the bay scallop fishery goes back centuries.
But in the last twenty years, the bay scallop fishery at Menemsha hasn’t been consistent. There have been years when the commercial fishermen did well and there were years when they didn’t bother to put their drags in the water.
Baby bay scallops have been spawned in the tribe’s hatchery and at the Martha’s Vineyard Shellfish Group.
The bay scallops, the size of a grain of sand, eventually are released into the pond.
“Last year we released over 150,000 baby bay scallops on the Aquinnah side of Menemsha Pond,” Mr. Stearns said.
“The smallest we’ve received have measured from 2 millimeters. And the largest we’ve released have been 30 millimeters in size,” Mr. Stearns said.
The bottom, an underwater meadow of bay scallop habitat, is protected from fishing and it is partly covered by large, vibrant eelgrass. The underwater grass offers the shellfish protection and a place to grow. On the surface are floating buoys that identify the area as closed to shellfishing.
Over the course of the past year, Ms. Kanozak has watched the scallops and monitored how well they survive and how well they cope with the changing seasons. She said she is just as interested in the health of the eelgrass bed. Next spring, she and Mr. Stearns plan to experiment on ways to transplant eelgrass from successful to not-so- productive areas.
Eelgrass is crucial to the survival of bay scallops. In their formative weeks of a bay scallop’s life, it needs a place to cling to just above the bottom.
On this sunny morning, both Ms. Kanozak and Mr. Stearns are underwater with clipboards. Wax pencils allow them to take notes below the surface. They count the frequency of animals in a given space. In the overall project, they are looking for changes in the population, survival rates for the different sizes, the impact of predators and other indicators of health.
At present, more New England bay scallops are raised successfully in China than in New England. Shellfish constables and fishermen on Cape Cod and Long Island are stymied on what needs to be done to jump-start their troubled bay scallop fisheries.
Two and a half million dollars have been spent on the eastern end of Long Island over the years to restore the fishery with only minimal success, according to Rick Karney, director of the Martha’s Vineyard Shellfish Group.
Mr. Karney’s hatchery helps provide juvenile bay scallops to Island towns that participate in the group.
There are plenty of reasons why the scientific experiment at Menemsha is important.
The bay scallop fishery is an income producer for communities where it is successful. It is a low-impact industry, with fishermen principally doing their harvesting in the off season in the fall and winter, and doesn’t conflict with the summer recreational season. A healthy bay scallop fishery also is a signature of a healthy coastal embayment. If bay scallops are doing well in a pond, Mr. Stearns said, then so is everything else.
Even more than bay scallops, “eelgrass is really the indicator of the health of a pond,” Mr. Stearns said.
Some nutrients in a pond can be helpful to the growing of plants and shellfish. But too many nutrients can be deadly, causing algae blooms.
“When you get nitrogen loading you get an algae mat over the eelgrass. Or the eelgrass can get covered in slime,” Mr. Stearns said. If the eelgrass disappears, so too does a lot of the life in a pond.
The science involved taking juvenile shellfish that are raised at either the tribe’s hatchery or the Martha’s Vineyard Shellfish Group’s hatchery in Vineyard Haven, putting them out in the water in the spring and hoping to harvest them 15 months later.
In the experiment, the shellfish are monitored from the time they are spawned and released. And they are released in different sizes.
Scientists already know the largest bay scallops released from a hatchery have the best chance of survival, but Mr. Stearns said the Menemsha study looks at putting together survival rates for those different sizes.
It gets costly holding onto the little bivalves for long periods before release. The study is looking to see if that expense is warranted and what are those benefits.
As part of the experiment, water temperature in the pond and outside of the pond is monitored. Further, Mr. Stearns said, “The water quality in the pond and in the Sound is monitored weekly and tested at the tribe’s laboratory.”
The study involves monitoring the native predators that feed on the bay scallops such as spider crabs, conch and even a few blue crabs. The study includes monitoring the more recent invasion of the green crab, a creature that arrived in these waters a century ago from the Orient and has had the most harmful impact on the survival of shellfish in the juvenile stage.
Just this summer, the team found an even newer predator, the Asian shore crab.
One of the key ingredients to survival of bay scallops is an aggressive program to catch crabs.
“In a 13-week summer season, we have caught 21,000 crabs each year for the last three years,” Mr. Stearns said. “I was surprised at how large the population of green crabs and spider crabs are in the pond.”
Support for the project goes beyond help from the Martha’s Vineyard Shellfish Group. Mr. Stearns said they are getting help from Brian (Chip) Vanderhoop, the Aquinnah harbor master and shellfish constable. They’ve received help and advice from Isaiah Scheffer, the Chilmark shellfish propagation officer. “We’ve also worked with Woods Hole Oceanographic Institution on bay scallop genetics,” Mr. Stearns said.
As for the tribe, he said, “We are using everyone in the natural resource department, hatchery staff and equipment.”
Next spring the tribe is getting a $30,000 device that can measure and monitor microscopic creatures in the water column from a boat. The device, called a Larval Identification and Hydrographic Data Telemetry Instrument, can quickly identify a whole host of larvae and zooplankton in real time.
“This will help us quickly and accurately identifiy bay scallop spawning events and the spawning events of their predators,” Mr. Stearns said. “That capability will significantly improve our understanding of bay scallop population dynamics.”
“The ultimate goal of this program is to identify processes, which are reproducible through the East Coast for the successful restoration of this important fishery,” Mr. Stearns said.
A report, a possible prescription for saving the bay scallop fishery, will be printed a year from now.
Aquinnah has yet to open the commercial bay scallop season, but the study is already having an impact on the waters of the town. The science is working. When the commercial bay scallop season opens next month, the tribal team expects an outstanding season.