Creating sanctuaries and aggressively managing the protection of juveniles are two of the low-cost ways towns can jump-start their bay scallop fishery, according to the results of a five-year study into how to promote the growth of bay scallops in local coastal ponds.
The federally funded study was conducted by the Wampanoag Tribe of Gay Head (Aquinnah). Bret Stearns, natural resource director for the tribe, said this week the $392,000 U.S. Fish and Wildlife study has produced results that coastal communities can use and many of the suggestions aren’t expensive.
The bay scallop fishery has been troubled throughout the region for many years. More than 20 years ago, communities on Cape Cod and out on Long Island depended on the fall and winter fishery for income. Yet Nantucket and Martha’s Vineyard seem to be the only communities in the region that have consistently produced bay scallops in harvestable numbers.
Up-Island waters were once highly productive. The tribe and the towns of Aquinnah and Chilmark have the records: Menemsha Pond once produced as much as 10,000 bushels of bay scallops in a season. Landings dropped from year to year; there is less consistency now. Invasive species such as green crabs were blamed for part of the decline. Water quality was also a factor. In the winter of 2004, only a handful of fishermen could find any bay scallops.
Using Menemsha Pond as a petri dish, the Wampanoag Tribe’s natural resource department has worked since 2005 to discover what can be done to restore the bay scallop fishery for the benefit of their community and others.
The resource department at the tribe started the study looking at water quality in Menemsha Pond, making an assessment of the bay scallop’s habitat and looked for ways to improve it. Working with the towns, the tribe set up a one-acre sanctuary in the pond where no fishing was permitted. It was marked by buoys and brought under the microscope. Juvenile bay scallops, not much bigger than a grain of sand, from the Martha’s Vineyard Shellfish Group and the tribe’s own hatchery were released in the sanctuary and watched closely.
Predators, including green crabs, were harvested and removed from the area to give the baby bivalves a better than lucky chance of surviving. Over three years the tribe harvested 21,000 green crabs a year from the pond using crab pots. Eelgrass, which is known as an essential part of the lifecycle of the bay scallop, was also monitored and managed in the area. In some places eelgrass was transplanted.
They found no genetic difference between bay scallops growing up on Martha’s Vineyard and elsewhere in the region and could surmise that the only reason Martha’s Vineyard bay scallops seem to do better is tied entirely to a better environment.
In just two years of doing the study, there was a huge benefit. Mr. Stearns said the harvest of bay scallops in Aquinnah went from 600 bushels in one season upwards to 4,000 bushels.
But the success of the study wasn’t just about buying large amounts of juvenile bay scallops and putting them into the pond, keeping the predators away and letting fishermen harvest them. It involved the shellfish constables from the two towns. It involved closing off a small area of the pond so that the bottom could be watched, often using scuba divers. As part of its results, Mr. Stearns said, the study came up with a number of low cost ways that towns can jump-start their bay scallop fishery.
“One of the most effective measures a town can take for a successful yield is to create protected areas. We call them sanctuaries,” Mr. Stearns said. These are places on the bottom that are closed to all shellfishermen. They are areas of aggressive attention. In that small area, there needs to be an active effort to remove all predators: green crabs, conch and starfish. A small town may not be able to clean up a whole pond, but they can make a difference taking care of one spot.
“Put your stock into these protected areas and it costs nothing,” Mr. Stearns said. The next year, the bay scallops that were protected become the spawners for future shellfish.
The next year, choose another place to be the sanctuary.
A bay scallops lives for about 18 months. They start their lives in the summer, become spawners the next summer and then are adult for harvest in the fall. By setting up sanctuaries, Mr. Stearns said, a community is not just protecting juveniles, it is protecting future spawners. That sanctuary can help start the bay scallops in other area.
The study also calls for a far more aggressive and active effort to protect the resource. Mr. Stearns said shellfish constables should not hesitate to shut down the fishery to harvesting if there is a concern about the risk of harming juvenile animals. This past winter is a case in point.
Last fall, Mr. Stearns said it looked as if Aquinnah were going to have a small bay scallop season, if any. Had they opened the season, the fishermen would have harmed a huge spread of juvenile bay scallops in the pond.
Mr. Stearns said the town chose instead to be proactive and protect the juveniles. “Much to our surprise there was not a large adult population of bay scallops in the pond, but the amount of seed was amazing. So, you have to take the right steps to manage, which includes, at times, a closed season,” Mr. Stearns said, adding:
“Fishermen want to make money, so it was a tough decision.”
In the months ahead, Mr. Stearns said, the results of the scallop restoration project will be posted at the tribe’s Web site for the benefit of other communities.
Meanwhile the work on the study will continue with a new piece of technology that was added to the natural resource department’s tool box just last summer. Last year, the tribe purchased a device capable of watching and identifying shellfish in the larval stage. It is a critical part of the bay scallop restoration story for it brings the science down to that stretch of a few weeks when the pond is filled with billions of floating bay scallop larvae.
During that time each summer, all adult bay scallops spawn and the spat are vulnerable. The spat floats for a short time before settling. Mr. Stearns said their electronic device, a Larval Identification and Hydrographic Data Telemetry (LIHDAT) system, can identify and count the tiny shellfish while they are in the water column. From there they can extrapolate a lot of data about how the larvae are doing.
“The unit takes in water, samples, identifies and counts the bay scallops in larvae,” Mr. Stearns said, adding:
“Software in the equipment can distinguish the different species of bivalves in a microscopic image.”
Andrew Jacobs, the bay scallop project coordinator, will be running the device.
Mr. Stearns said they already know pretty much when the bay scallops spawn. They already know the critical time when the larvae are floating. But this device will help the researchers come up with a better understanding of ways to increase the survival of that spat.
It is already understood that the larvae can be adversely impacted by weather events, storms, rain and wind and harmful pollution. Mr. Stearns said they want to put more science behind that critical period in the life of the animal.
“Spat comes to us free every year,” Mr. Stearns said. “We want to know what it is we can do to improve their survival. We want to know where the larvae set, when they go to the bottom. We want to know where the places are that they survive and where they do not,” he said.
The work is not over. From there, Mr. Stearns said the tribe will continue to have a dialogue with the two towns about other attainable goals for helping the bay scallop fishery. “I would like to have an open discussion about the management of the pond,” Mr. Stearns said. It might down the road include protecting the water quality, and it might include dredging.
The one single principle that has arisen from the study is the understanding that the bay scallop fishery is not one that will take care of itself. Today communities must work actively to restore their bay scallops. It is not enough just to wait for the bay scallop fishery to come back; it is a fishery that needs help.
“The tribe’s goal here is to have a future sustainable yield,” Mr. Stearns said. “Fishing and shellfishing are important to the tribe. It isn’t just about having a key species, it is about having a resource continue into the future. It is about sustenance food. This is about feeding the family.”