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Feature Articles
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Maine's experimental fishery leads to first Atlantic halibut spawning
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This article is reprinted with permission of Commercial Fisheries News, the Northeast's fishing newspaper for over 30 years, ©2003 Compass Publications Inc. Commercial Fisheries News is published monthly; annual subscriptions are $21.95. To subscribe or request a sample issue: call (877) 263-4496; fax (207) 367-2490; e-mail (cfoster@fish-news.com); or click on the hot link.
FRANKLIN, ME - Spawn Atlantic halibut for wild stock restoration or even growout? Sounds incredible, but efforts started a few years ago to do just that started paying off this spring.
Working with wild-caught broodstock, scientists at the University of Maine's Center for Cooperative Aquaculture Research (CCAR) successfully spawned an Atlantic halibut this spring. It was the first time a halibut has been spawned in captivity in the United States.
The broodstock was captured by Maine commercial fishermen who were working under a federal Experimental Fishery Permit for a Gulf of Maine halibut fishery.
CCAR operations manager Nick Brown said that the eggs stripped from the young female fish informally christened "Eve" were unlikely to survive in significant number. That is to be expected, he said, the first time a wild fish is spawned in a hatchery. Still, late in May, the hatchery held a small number of the larvae resulting from the happy event.
Brown's team also successfully hatched a number of halibut eggs purchased from the Canadian Department of Fisheries and Oceans in New Brunswick. Those eggs were fertilized with sperm from male halibut held at CCAR.
Initially, the larvae were kept in total darkness in temperature-controlled, covered tanks that simulated the deep ocean environment where halibut larvae spend the yolk-sac stage of their lives.
By late spring, several hundred of the tiny juvenile halibut had been moved to brightly lit tanks and switched to a live feed diet of Artemia, also raised at the Franklin site.
Events have moved swiftly at the applied research facility. The university purchased the derelict salmon hatchery at a mortgage foreclosure sale late in 1999 and began cleanup and maintenance of the property.
By the summer of 2000, the hatchery had received 31 wild halibut caught by Maine fishermen participating in the exempted fishery. Brown joined CCAR in April of 2001 and, since then, the fishermen have furnished the facility with another 76 wild halibut. In all, CCAR has about 60 surviving adult halibut in its tanks, which it hopes will form the basis of a population broodstock.
The three-year experimental fishery has involved up to six Downeast boats fishing during a limited spring/summer season. The boats were permitted to fish for halibut in federal waters with longline gear and sell their catch while complying with biological sampling protocols and tagging undersized halibut.
The Maine Department of Marine Resources (DMR), in conjunction with the National Marine Fisheries Service and Maine Sea Grant, has administered the experimental fishery. A special permit was needed because federal rules currently allow the possession of only one halibut per day in federal waters.
The purpose of the experimental fishery was to tag and release fish and collect biological data about the stock that could be used develop a sustainable management plan for the fishery. The first tag returns were received last winter from the 2000 fishery.
In March, rules were implemented for a state waters fishery that closely parallel the experimental program.
For more info, contact DMR's Kohl Kanwit at (207) 633-9535 or e-mail kohl.kanwit@state.me.us.
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