STONINIGTON – Last month, lobstermen Marsden Brewer and his son, Bobby, joined a delegation of Maine fishermen and aquaculturists on a visit to Aomori on the northern coast of Japan’s major island to learn about the latest techniques for cultivating scallops.
Among their hosts was Hiroaki Sugiyama, an inventor and manufacturer of high-tech machinery used in Japan’s enormous scallop aquaculture industry.
On Monday, the Brewers returned the favor.
Sugiyama arrived in the U.S. Sunday night for a four-day visit to learn about what is happening in Maine’s nascent scallop aquaculture industry. After a stop at a newly-formed aquaculture cooperative in Spruce Head, and a boat ride to visit an experimental scallop growing operation, Sugiyama and his Maine hosts traveled to Stonington for more talk about scallop aquaculture, and a terrific lunch, hosted by Marsden and Donna Brewer at their Red Barn Farm.
Brewer first travelled to Aomori in 1999 as a member of a study mission organized by the Maine Department of Marine Resources and the Maine Aquaculture Innovation Center. Including fishermen, scientists and representatives of the University of Maine Sea Grant program, the group visited Mutsu Bay in Aomori Prefecture where the Japanese scallop is intensively cultivated both on longlines and on the seabed.
Even before that trip, Brewer was experimenting with collecting scallop spat (juvenile scallops) from the wild — determining which areas and conditions were most productive — and growing scallops in wire cages.
“The 1999 trip was really an introduction to spat collection and a little bit of growout,” said Dana Morse, a member of the Sea Grant Marine Extension Team who travelled to Aomori on that trip and again last month.
The recent trip, though, focused on methods of growing juvenile scallops to marketable size. Of primarily interest to the travelers was the technique known as “ear-hanging” in which thousands of pairs of small scallops are hung on hanging ropes using tiny plastic pins inserted in holes drilled through the flat “ears” that form part of the scallop shell hinge.
The technique allows scallops to reach market size more rapidly than the other technique common in Japan — growing large numbers of scallops in hanging “lantern nets” or pearl nets and reducing the number of scallops in each net as the scallops grow.
One problem with the ear-hanging technique was that — as practiced in 1999 — it was extremely labor intensive and, accordingly, expensive. Drilling every hole, inserting every pin, attaching every scallop to the hanging line — each action was done by hand by a skilled fisherman.
Machinery invented by Sugiyama and manufactured by his Mutsu Kaden Tokki Co. Ltd. has solved that problem. His machine precisely drills each scallop ear, automatically inserts the hanging pin then attaches the pinned scallop to the rope that will be used for the suspended line.
The primary goal of this year’s trip to Aomori, Morse said, was to learn about ear-hanging and “understanding the machinery involved.” According to Brewer, that goal was met.
“The trip was good,” Brewer said Monday. He was impressed with the way the ear-hanging methods have evolved to require the use of a single machine.
“Now you load in the rope, load in the pins, load in the scallops and it all comes out the other end,” he said.
It may not be too long before Brewer and other interested growers get a chance to see how those machines might work in Maine.
Sated by a lunch that featured Donna Brewer’s cooking and raw scallops grown by her husband, Marsden, and son, Bobby, Sugiyama said he might bring one of his machines to Maine for a demonstration next year.
Ear hanging scallop aquaculture has “a lot of potential for Maine,” Brewer said, but it is not without risk. The Sugiyama machine is expensive, and it takes three years for a scallop to grow to marketable size. That’s a long time for grower to wait before realizing any income from his operation.
The market in Japan is different from the market here in Maine. For one thing, Brewer said, 70 percent of the scallops grown around Aomori are harvested for their meats when they are “less than mature,” about two inches in size. In Maine, the effort has been aimed at marketing a larger, whole scallop.
Another difference is the scale of the scallop aquaculture business in Japan. According to Brewer, Japanese growers harvest about 100,000 metric tons (about 220 million pounds) of scallops. Of that, about 70 percent of the harvest is sold at the less than mature stage and processed into a variety of scallop products.
By comparison, the 2015 wild scallop harvest in Maine was about 453,000 pounds and there was virtually no commercial harvest of cultured scallops.