June 21, 2018
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Machias professor makes lobster aquaculture breakthrough

By Bill Trotter, BDN Staff

GREAT WASS ISLAND, Maine — Though there is no shortage of lobsters in the Gulf of Maine, some scientists and lobster fishery officials have been trying to learn how to reproduce the crustaceans in captivity.

As other commercial fisheries in Maine have dwindled or nearly vanished, the amount of lobster caught in the gulf each year has shot up dramatically over the past two decades. Last year, for the first time ever, more than 100 million pounds of lobster were brought ashore by Maine fishermen, who earned an estimated total of more than $330 million for their catch.

But as the lobster industry has come to dominate commercial fishing in the state, some scientists have expressed concern about what might happen to Maine’s coastal economy if the gulf’s lobster population were to collapse. As a precautionary measure, some fishermen, scientists and industry officials have tried hatching millions of tiny juvenile lobsters and then letting them loose in the ocean.

But according to Brian Beal, there have been some serious scientific shortcomings to those efforts. Producing millions of tiny lobsters, each as long as a dime is wide, and setting them afloat in the gulf is well and good, but what happens to them after that? Have any of them ever grown big enough to be legally sold in Maine? Do they ever settle to the bottom? Are they all eaten by fish as they swim around in the water column?

In short, is there any indication that hatching millions of tiny lobsters and dumping them in the gulf does any good? Beal, a University of Maine at Machias professor and director of research at Downeast Institute, says officials just don’t know.

But Beal says he has come up with a better way to grow lobsters in captivity. Through trial and error over several years, he has learned how to grow lobsters in a protected environment until they are several inches long — not big enough to be sold, but big enough to settle to the bottom when they are released and possibly to improve their survival rate.

And, he said, he has a way to put identifying tags on them that will last through several sheddings, though likely not until they are big enough for fishermen to keep. Still, if tagged undersized lobsters show up in traps after being released, it will help officials keep track of how many of them are surviving in the wild, he said.

“The larger the animal you put back in the ocean, the better its chance of survival,” Beal said during an interview at Downeast Institute. The full name of the nonprofit research lab, located at a former indoor lobster pound on Great Wass Island in the Washington County town of Beals, is Downeast Institute for Applied Marine Research and Education.

Beal started his research into how to grow lobsters in the mid-1980s when he established a hatchery with lobster fishermen in Cutler. By the early 1990s, he began developing theories about how to grow them to a benthic, or bottom-dwelling, stage. In 2000, he got the chance to put some of those theories to the test as a Fulbright scholar at the University of Ireland in Galway.

His idea was to put small lobsters in artificial shelters submerged in the ocean and to let the natural currents provide food to the captive crustaceans, each kept in a separate container. If the container held up and enough food in the form of tiny creatures washed into it, the lobster inside would grow over a period of several months with no additional active assistance from people, he theorized.

“From an aquaculture standpoint, you don’t have to feed these things,” Beal said.

Beal said he tried all types of containers to house his tiny lobsters, first in Ireland and then back at Downeast Institute. He tried using pouches of mesh material he stitched together by hand. He tried large plastic petri dishes, one inch deep and six inches wide, with holes drilled into the lids. He tried plastic beverage bottles, wooden trays with partitions and milk jugs, each with holes drilled in them to let water flow through.

He got different success rates. Lobsters placed in the mesh pouches had a survival rate of about 30-40 percent. The assorted plastic bottles had varying rates, including one deployment which resulted in 1,000 bottles filling with mud and only one lobster surviving.

The plastic petri dishes with multiple small holes, however, had a success rate of 75 percent. When he took plastic petri dishes the same size, cut one large doorknob-sized hole in the top and then glued a piece of mesh over the hole, he said, his success rate went to over 90 percent.

“Determining the flow is critical,” Beal said about what size aperture is ideal for letting food flow in and sediment flow out. “There weren’t enough holes in these [beverage] bottles. Essentially, they became sediment traps.”

The most surprising thing Beal has found, he said, relates to the lobsters’ growth rate. Juvenile lobsters the same age and from the same female, he said, can grow at different rates depending on how large a container they are kept in. A one-inch lobster can double in size over several months in a relatively small container. An identical lobster placed in a container the size of a shoebox, he added, can grow to six inches in the same time period.

“The lobsters grew to the size of the container,” Beal said. “The larger the container, the larger the lobster. … None of this has ever been done before.”

Beal and George Protopopescu, assistant director and supervisor of the institute’s shellfish hatchery, recently published their findings in the Journal of Shellfish Research.

Bob Bayer, professor of animal science at University of Maine and executive director of the university’s Lobster Institute, said Thursday the journal is a respected scientific publication produced by the National Shellfisheries Association, which has promoted shellfish research for more than 100 years.

There might not be much immediate demand or practical use for Beal’s findings in Maine, Bayer said, but there might be in southern New England, where lobster stocks have declined dramatically in recent years.

“That would be the place to test it,” Bayer said about breeding lobsters for stock enhancement at a commercial scale. “It’s good to know you can do it.”

Beal agreed that his research might bode well for rebuilding stocks south of Cape Cod, but said the ability to raise lobsters in captivity also raises other economic possibilities.

The concept of a minimum harvestable size in Maine long has been strictly adhered to by officials and fishermen alike as a way to help ensure the species’ ability to reproduce at a healthy rate and to keep the fishery sustainable, he said.

The purpose of his research was to find ways to help boost the stock of wild lobsters, Beals said, but if lobsters can be raised in captivity with a significant success rate, why not allow those lobsters to be sold at a smaller size? If a captive broodstock can be maintained without any long-term impact on the wild population, he said, there would be no environmental or economic reason against selling lobsters raised in captivity that are only six to eight inches long.

There could be different markets for smaller lobsters, Beal said. Many types of fish are bred as ornamental species for people who keep fish tanks and there might be a demand for small lobsters that people would keep basically as pets — at least for as long as they are small enough for household aquariums, he said.

Or they could be sold as a separate kind of delicacy, he said. No doubt some people would prefer to eat a single 1.5-pound lobster as a meal, he said, but some may opt to eat several smaller lobsters at once, the way people might eat a plate full of crayfish. He estimated that small lobsters could be raised at an expense of 25-30 cents each, but still could fetch a premium price from high-end diners.

“Those are examples of using the industry to make other economic opportunities,” Beal said. “It could be a concept that dies on the vine. All I’m saying is ‘Here’s what is possible.’”

Bayer said the prospects of commercially breeding what are considered undersized lobsters could “open a can of worms” from a law enforcement perspective because Maine Marine Patrol officers would need a way to know that the lobsters have been bred in captivity rather than caught in the wild.

Special tags could be one way of identifying such lobsters, he said. Alternatively, such lobsters could be selectively bred to have a special appearance that is rare in the wild and could not be caught in traps at rates that breeders could produce. An unusual shell color such as blue or calico would identify a shipment of small lobsters as aquaculture products, according to Bayer.

“I think it’s pretty neat,” Bayer said of Beal’s research. “I think he’s onto something.”

Follow BDN reporter Bill Trotter on Twitter at @billtrotter.

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