Commercial scalloping has been a dicey proposition since the East Coast scallop population inexplicably crashed between 1984 and 1987. No one has been able to explain why the scallop fishery collapsed or why, in a given year, like 2009, the scallop harvest rebounds to glut the market.
Achieving a consistent harvest from year to year is the goal for fisheries managers.
The Island and Nantucket have fared better than most East Coast scallop shell fisheries. Long-time Island managers of the persnickety shellfish believe management practices they’ve had to learn over the past 25 years help the Island to avoid the peaks and valleys.
“We’ll have 1,000 bushels maybe 1,200 bushels, in Oak Bluffs this year, about the same as last year,” Oak Bluffs shellfish constable David Grunden estimated in a recent interview. “We’ve evened out the bouncing around of ten years ago where harvests could fluctuate from 500 to 1,500 bushels from year to year,” he said.
Paul Bagnall, Edgartown shellfish constable, had a similar, though slightly lower, harvest prognosis last week. “Early on, guys were able to make the (three-bushel daily) limit pretty quickly, now it’s taking a little longer or they may just get two bushels, but with prices up, it’s still a day’s pay,” he said.
Expected harvests vary by degree around the Island. In Aquinnah, for example, where the commercial season began November 15, fishing has been good through the first four weeks despite early concerns that predators feeding on seed last winter would limit the harvest.
Scalloper Giles Welch reported last week that he was able to harvest his daily limit in just a few hours early in the season and views the harvest as solid this year.
“It’s beginning to slow down now. There was plenty of seed in there but the eider (ducks) have been feasting on it,” he said.
Island shellfish managers spend a lot of time and trial and error attempting to understand the balance required to produce a healthy scallop population.
Scallops are sensitive animals. Shellfish are sensitive animals, normally live for just two years, are difficult to raise to adulthood in captivity and require a specific natural environment with clean water, current, and lots of eel grass to flourish.
“We used to just fish Edgartown Harbor, no one ever went to (Cape) Pogue. You could get what you needed right in the harbor. Same thing on the Cape and Buzzard’s Bay. Towns like Westport, Chatham and Falmouth all had strong shell fisheries,” Mr. Bagnall said recently
Veteran fishery managers like Mr. Bagnall, Mr. Grunden, and Rick Karney, director of the shellfish hatchery in Oak Bluffs, are relying on technology, 25 years of accumulated knowledge, and a growing bank of data, and the commercial fishing community to enhance the Island scallop fishery and to avoid surprises.
The 2010 season was a prime example of the unpredictability inherent in the scallop business. Island and Nantucket harvests were strong, and for some reason, both Chatham and Long Island, minor players in recent history, had a scallop boom. Over-supply early in the season drove wholesale prices as low as $6 and retail prices to $12 and $13, forcing many Island fishermen to look for other work until prices rebounded.
This year, the Island and Nantucket harvests are solid, but Cape and Long Island scallops are not present to glut the market. Result?
“We’re paying $15 wholesale and getting $18-19 retail,” Dan Larsen, owner of Edgartown Seafood, said last Sunday. Early season prices last year were as low as $8 wholesale and $13 a pound retail.
While natural predators like blue crabs and birds are a fact of life, their impact varies by season. This year, eider ducks are most discussed. “We had a warm winter, the ponds didn’t freeze so the ducks were able to get at the seed,” Mr. Bagnall reported.
On the Island, largely as a result of research at the shellfish hatchery in Oak Bluffs, Island shellfish managers have learned that two to three million seeds a year are needed in Island waters to achieve a consistent harvest. They also know what size and age the scallop seeds must be for optimum results. Success over the past four seasons has attracted attention. Nantucket has adopted the hatchery model and Westport is planning one, Mr. Bagnall said.
On the technology side, Oak Bluffs will soon deploy an underwater laser scanning system with GPS to aid in monitoring scallop, an upgrade from an underwater photography system unveiled by the Woods Hole Oceanographic Institute just four years ago.
Scallops require healthy stands of eel grass for protection and for sustenance while they grow to maturity. The eel grass cover has been shrinking on the Island.
Dredging, the harvesting method used here, involves dragging a smooth bar across the surface of the bed, raising the scallops and allowing them to fall into a trailing net.
Shellfish managers believe their controlled dredging methods and regulated monitoring are the keys. “Some southern fisheries allow bars with teeth which can tear up the bottom and the eel grass-roots. We don’t allow that,” Mr. Karney noted this week.
“Dredging has been around since the outboard motor,” Mr. Karney said.
While eel grass is affected by dredging, the key is to leave the roots undisturbed, Mr. Bagnall said. “Think about it. It’s just like thatching your lawn once a year. New grass grows more easily,” Mr. Bagnall said. “If dredging destroyed eel grass beds, we’d have done it 30 years ago in Edgartown when we landed 150 limits a day,” the former scalloper said.
What threatens the scallop environment the most? “Humans,” said Mr. Bagnall. “Technology has been a boon and an evil. It did promote overfishing but technology has also given us tools to enhance the fishery.
Development, the arrival of more people, has had the greatest impact by diminishing water quality through nitrogen loading. That’s a major threat to the scallop environment,” he said.
One question, not the subject of formal study on the Vineyard, is the effect dredging has on the health of the scallop fishery and eelgrass.
A team of researchers at the University of North Carolina at Chapel Hill studied that question. The researchers published their findings (available at mvtimes.com) in an October 2005 study, “Effects of harvesting methods on sustainability of a bay scallop fishery: dredging uproots seagrass and displaces recruits.”
The study looked at two methods of harvesting scallops: toothless dredges and hand-harvest using nets and rakes in a controlled area.
The study concluded that dredging had only a short-term impact on seagrass growth and appeared to stimulate new growth. However, repeated dredging caused scallops to migrate from areas of seagrass and is likely detrimental to seagrass habitat and, “as an indirect result, the abundance of bay scallops that make up the next generation,” the study said.
“The results of our study raise doubt about the sustainability of a bay scallop fishery in which the harvest method is dredging,” the study said. “Because this species, which lives only 12-24 months, is recruitment-limited, reductions in densities of juvenile bay scallops by dredging will only diminish that year’s harvest but also presumably result in less spawning-stock biomass.”
The study said gear restrictions on dredgers in shallow areas where hand-harvest is practical may pay big dividends.