Slow going for island scallop seed production at Dennis hatchery
BY PETER B. BRACE INDEPENDENT WRITER
Propagation of one million seed scallops at a hatchery on Cape Cod is taking longer than expected.

"They're scallops; they're touchy; they're difficult to spawn and grow out." - Keith Conant, Nantucket Town Biologist

Late last winter, Town Biologist Keith Conant contracted with the Aquaculture Research Corporation of Dennis to spawn and grow out one million seed scallop (juvenile scallops) to one to three millimeters in size for $6,500.

But spawning bay scallops anywhere other than in the wild is proving to be much tougher than anticipated, according to Conant.

"They had some procedural failures in the hatchery that caused one hundred percent mortality of the larvae in the first batch," said Conant. "They tried again, and I'm not sure if they had the same problem as they did the first time, but the larvae had 70 percent mortality the second time.

"They're scallops; they're touch; they're difficult to spawn and grow out."

Nantucket's own attempts to spawn and grow out large quantities of scallops over the last decade-and-a-half by several entities in the Brant Point Boathouse marine lab were spotty at best. The town's last attempt at seeding Nantucket Harbor yielded no results at all. The Marine & Coastal Resources Department put 300,000, 50mm scallops that were spawned off island in waters off Second Bend, but they were never seen again.

Bay scallops are more of a special order for ARC, Conant said, as the Dennis hatchery's primary spawning work comes from coastal towns needing quahogs, soft-shell clams and oysters.

"Anything could have gone wrong," said Conant of ARC's first two failures this year. "They don't know. It could have been the wrong type of food, not enough food, mishandling, maybe too many male gametes clogging the filters."

With much hesitation, the Shellfish & Harbor Advisory Board voted last winter to send adult scallops off island to the hatchery to get seed that could be grown out in floating cages in Nantucket Harbor to release size, around 50 millimeters, or about the size of a quarter, to help save steadily dwindling populations of bay scallops in Nantucket waters.

The 2006/2007 scallop season netted just 3,850 bushels of scallops and the season before that, commercial scallopers dredged 5,500 bushels. Island scallopers, Conant and SHAB hope to revive the scallop industry with these one million seed. Conant said that ARC would keep spawning adult scallops until they produce enough seed to meet their contract with Conant.

"It doesn't mean that we won't get them," he said. "We'll probably get the seed from them around the same time our local scallops have spat and be around the same size."

What Conant is unsure of is whether ARC will grow out the 300,000 seed it produced. They may want to scrap that batch in order to keep operating at capacity. The most likely scenario for Nantucket is that its scallops will cooperate around the time of the first spawn in the harbors; when harbor water temperatures reach 68 degrees Fahrenheit, a biological that causes bay scallops to spawn.

"We'll probably get them in the middle of July and hopefully this time around they won't have as many problems,"

said Conant. I