NANTUCKET - Matt Herr had a good day out on the harbor.
It took five hours of towing and unloading dredges, then sifting through seaweed, crabs, and muck, but he had made his five-bushel daily limit of bay scallops.
Now, with a cold breeze beginning to bite through layers of clothing and gale-force winds on the way, he was pushing to get back in before noon.
"It can get nasty in a hurry," said Herr, 41, who has been scalloping on Nantucket for 20 years.
If New England's fickle weather were the only uncertainty in Nantucket's commercial bay scallop season, which runs from Nov. 1 to March 31, this 6-mile-long harbor might be more jammed than Route 128. But Nantucket scallopers, whose haul has accounted for more than half of the state's bay scallop harvest over the past decade, face boom-and-bust cycles that can drive less hardy souls to despair.
This season has been going strong, but over the past three decades the world-famous Nantucket bay scallop fishery's catches have dwindled and fewer young people are getting involved.
No one knows exactly what has caused the decline in harvests or what drives the occasional spikes. But Nantucket's catches were at a record low last season, raising a red flag over what, even in reduced years, is generally the most robust bay scallop population in the Northeast.
"We're pretty much the Alamo here," said Sarah Oktay, managing director of a Nantucket field station operated by the University of Massachusetts at Boston. "We're trying to be the last group that survives, that doesn't have to depend 100 percent on things like aquaculture."
Among possible causes cited by specialists for the ebbing bay scallop population off Nantucket, where summer and year-round human populations have soared and real estate values have skyrocketed, are the proliferation of invasive predators such as the green crab and the reduction of eelgrass.
Eelgrass, a crucial component of scallop habitat, has thinned for a variety of reasons, including the blooming of algae that are nourished by nutrients from fertilizers, septic systems, and boats. Eelgrass, which is shaded out by the algae, can also be ripped up by anchors, mooring chains, and fishermen's dredges.
And in some parts of Nantucket's main harbor, where about 75 percent of the bay scallop fleet fishes, an invasive seaweed known as Codium, or dead man's fingers, is crowding out eelgrass.
The bay scallops' short lifespan, two to three years at most, makes the shellfish hypersensitive to environmental changes but also enables stocks to rebound quickly.
"The scallop, they have said, is like the canary in the coalmine," said Herr, a member of the town's Shellfish and Harbor Advisory Board. "If you start to see a decline in your scallop populations, you know that there's something going on with your water."
Nantucket's catches, measured in plastic bushel boxes that each hold about 400 scallops and about 8 pounds of shellfish for market, rose to 117,000 bushels in 1980-81. The harvests dropped from there, falling last year to 3,800 bushels.
"I guess disturbing is the best word for that," said Dave Fronzuto, the town's marine superintendent, who emphasized his concern for the scallopers' welfare.
About 60 boats were out on opening day last season. By the end of March, scalloper Neil Cocker said: "I think there were five of us. It was pretty quiet out there."
But this season, with catches back up, the harbor has been bustling. Heading into this week, about 15,500 bushels had been landed, according to Fronzuto, who added that about 30 bay scallop boats have been working on a daily basis.
Nantucket's scallopers are not alone in suffering meager harvests. "Generally, they have fared better than anybody else, but they are definitely following the statewide trend, and the state is following the coastwide trend," said Michael Hickey, chief shellfish biologist for the state's Division of Marine Fisheries.
Last year, Nantucket's Marine and Coastal Resources Department sent 100 adult scallops from Nantucket to a state-certified hatchery on Cape Cod, which returned a million seeds, each the size of a grain of sand. In October, they were placed in a seed sanctuary in the harbor, in an effort to bolster the fishery by using a form of aquaculture. The town has sent scallops off-island to be spawned about a half-dozen times and plans to do so again this year, Fronzuto said.
In August, Nantucket hired a new shellfish biologist, Jeff Mercer, in part to allow the Marine and Coastal Resources Department to more closely monitor the town's bay scallop fishery.
Mercer set out to enlist scallopers to collect data on the shellfish, such as location and ages. "There are 70 or 80 of them and only one of me, and they're out there all day, so it's a good source of information," Mercer said.
Herr sees Mercer's effort to reach out to the fishermen as an opportunity to improve cooperation and hasten progress. The town's fishermen and marine department have had disagreements, including over the complicated issue of harvesting so-called nub scallops, which are born late in the spring-to-fall breeding season. For the time being, the town is allowing the harvesting.
The bay scallop, smaller, sweeter, and more expensive than the sea scallop harvested offshore, is Nantucket's largest commercial fishery and a crucial source of income for many of the 11,100 year-round residents on this island 30 miles south of Cape Cod.
At Whole Foods at Charles River Plaza in Boston on Friday, the tiny, ivory-colored Nantucket delicacies were priced at $27.99 a pound, alongside sea scallops for $15.99.
Scalloping is part of the island's culture, said Whitey Willauer, chairman of the Nantucket Board of Selectmen. "This is historically what the Nantucketers did during winter to tide themselves over," he said.
For most scallopers, it supplements income. "These are not commercial fishermen," Fronzuto said. "These are not the guys from Gloucester. These are not the guys from New Bedford. These are carpenters, masons, builders, painters, chefs. I have very few who fish year-round."
But scalloping is a way of living that might be dying. The number of scallop licenses sold in Nantucket has dropped from a peak of 440 in 1990 to 147. "You don't see young people getting into the fishery," Fronzuto said.
Marina Finch, the Nantucket bay scallop fleet's only female captain and a member of the Shellfish and Harbor Advisory Board, said scalloping can be difficult to break into because of the high cost of getting started, and it's tough to stick with due to the cycles. "It's hard work, and it's not always dependable," she said.
Days are lost occasionally when fishing is shut down due to severe cold or icy conditions. When the ice thaws, it can be dangerous. "It's scary to fish in the ice," Finch said. "You have to be really careful because it moves around with the current and tide. The ice can actually climb up your lines and pull the back of the boat under."
But there are rewards. The average price per pound paid to scallopers has climbed from just over $5 in 1978 to about $14. One recent day, Finch made $440, after shelling out $120 for workers to open her scallops, and estimated that this year she would earn close to $30,000 scalloping. Finch plans to fish for conch in the summer and work in a wine store.
Some benefits extend beyond the monetary.
"You're outdoors, breathing fresh air," Herr said after a day of fishing at the beginning of the season. "You're looking for something. It's like a scavenger hunt, a treasure hunt. The possibility of success is always there.
"But it's very difficult to hang on. You've got to have some perseverance. It's tough."
