Wednesday, September 7, 2011

Crustacean Science

By Doug Schneider

University of Alaska, Fairbanks (UAF) scientists are working with fishermen, the seafood industry, state and federal researchers and coastal communities to raise king crab in hope of rebuilding once-lucrative fisheries.

Inside the Alutiiq Pride Shellfish Hatchery, an otherwise nondescript warehouse on the south end of the fishing and tourism town of Seward, Alaska, thousands of recently hatched red and blue king crab larvae have started to look like crab.

Just a few weeks earlier these king crabs were embryos within eggs tucked neatly beneath their mothers’ abdominal flap.

The baby crab have so far grown through the major steps of larval development, collectively called the zoeae stage. At the moment, they are well into the next stage, called glaucothoe, during which they take on features common to all crab. They brandish tiny claws on their front legs. Large, beady black eyes sit atop their heads. In a few more weeks, these crabs will have armored shells and be instantly recognized as Alaska’s biggest crab.

“They start out small,” says biologist Jim Swingle, a crab research biologist with Alaska Sea Grant. “It’s amazing to see them develop.”

For each of the past five years, Swingle and fellow Sea Grant biologist and UAF graduate student Ben Daly have carefully cared for and watched over the adult female king crab and the growth of their numerous offspring.

The efforts are part of a UAF partnership with fishermen and trade associations, coastal communities, and state and federal scientists, to develop the biological understanding and technology to hatch and raise large numbers of king crab from wild broodstock. The project also seeks to learn more about the ecology and biology of wild crab and how hatchery crab might fare if released into the ocean.

“Overall, the research is aimed at learning whether raising red and blue king crab in hatcheries is feasible to help low numbers of wild king crab stocks recover in places like Kodiak Island and the Pribilof Islands,” said Dr. David Christie, director of Alaska Sea Grant.

Like many large scientific research programs, this one has a catchy name – the Alaska King Crab Research, Rehabilitation and Biology, or AKCRRAB, program.

King Crab Boom, Then Bust
For decades, Alaska crab fishermen from Southeast to the Bering Sea happily rode what seemed to be a tidal wave of king crab. Beginning in the late 1950s, Alaska crabbers hauled in seemingly bottomless boatloads of red king crab. At the peak of the fishery in 1965, fishermen caught 94 million pounds of the colossal crustacean, valued then at $12.2 million. At today’s price paid to fishermen, the value would be $500 million.

Scenes of huge crab catches played out in Bristol Bay, too, where fishermen in 1980 hauled in 130 million pounds of red king crab, worth $115 million. (That’s $650 million for fishermen in today’s dollars.)

Fishermen eagerly hunted blue king crab as well. At the peak in 1981, fishermen in the frigid Bering Sea around the Pribilof Islands and St. Matthew Island filled their boats with 14 million pounds of blue king crab.

But the boom was not to last. In 1983, after years of plummeting harvests, Kodiak fisheries managers finally pulled the plug. The closure was a huge economic blow to the island’s economy. And even though commercial red king crab fishing has been closed around Kodiak for more than 30 years, the stock has not recovered. Around the Pribilof Islands, blue king crab have not fared well either. After years of erratic catches, the blue king crab fishery closed in 1999. Officially, the blues there are classified as overfished.

Grassroots Call Spurs UAF Research
In the decades following the collapse, fishermen called for a hatchery program to rebuild king crab stocks around Kodiak and the Pribilof Islands. In 1992, Kodiak residents convened a workshop on Kodiak crab crash and what might be done to help the stocks recover.

The hatchery idea came up again in early 2006 during conversations between Arni Thompson (then with the Alaska Crab Coalition), Heather McCarty of the Central Bering Sea Fishermen’s Association, and Gale Vick with the Gulf of Alaska Coastal Communities Coalition.

“We were all talking and I asked some totally naive questions about the possibilities of enhancing the wild king crab stocks, and from there Arni arranged for us to meet with several scientists,” says Vick. “From there, it picked up steam with the communities and other fishermen’s groups. The beginnings were truly grassroots.”

Soon after, the group asked UAF’s Alaska Sea Grant College Program to examine the hatchery idea. In March 2006, Alaska Sea Grant hosted a workshop with fishermen, state and federal biologists, community leaders, seafood processing companies, and fishing organizations, to discuss the status of red and blue king crabs and the prospect for hatcheries to help rebuild the stocks. Former Alaska Sea Grant Director Brian Allee recalls the mood of the people in the workshop.

“The consensus was that enough time had passed, that nature needed a little help,” says Allee, who now works for NOAA helping rebuild salmon stocks in the Pacific Northwest. “The fishing industry wanted a research and development program to test the feasibility of hatcheries as a way to rebuild the crab stocks.”

Taking cues from this meeting, Alaska Sea Grant pulled together university and federal biologists, fishermen, Alaska coastal community leaders, and the Alutiiq Pride Shellfish Hatchery to form the AKCRRAB program, and begin research.

That was five years ago. The rest, as they say, is history.

Hatchery Research Progress
In 2007, hatchery research began in earnest, thanks to fishermen who provided scientists with 36 adult female king crab whose abdominal flaps were stuffed with eggs.

“The exact number of eggs varies with the species and size of the female crab but it is usually between 150,000 and 200,000 eggs for each red king crab, and fewer for the blues we have this year,” says Alaska Sea Grant’s Swingle.

Scientists at the Alutiiq Pride hatchery monitored the expectant female crabs, making sure water temperatures, salinity, flow rates, and other factors in the hatchery’s seawater tanks were just right.

Then, around the end of March and early April, the eggs reached the hatch-stage, and the larvae began to wiggle free from their eggs. In all, some four million red and blue king crab larvae hatched in that first year.

“Getting the first hatch back in 2007 completed was great, but at that time, we didn’t know that much about how to take care of the larvae; what they ate, the exact combination of water temperature, light, food, and other critical needs,” Brian Allee, the Alaska Sea Grant director at the time. “We were learning as we went along.”

The early problems resulted in the loss of nearly all the larvae that first year. Although a setback, no one expected a flawless first year.

“No one had tried this before with Alaska crab,” said Allee. “We learned a lot and we made adjustments.”

With new equipment that enabled researchers to maintain optimum water temperatures, and having learned valuable lessons about how to handle and feed the crab larvae, researchers made steady progress during the following years.

“The key to being successful in the hatchery has been trying to get all the different elements dialed in,” explained Swingle. “You have to get the feed, seawater flow rate, aeration, temperature, and other factors just right. A lot of things have to come together to be successful. So over the years we have improved these things.”

The improvements paid off. In 2008, Swingle and Daly and the staff of the Alutiiq Pride Shellfish Hatchery were able to get 31 percent of newly hatched larvae to the glaucothoe stage. Of these glaucothoe-stage crabs, 10 percent survived to the first juvenile stage – the animal has fully formed legs, shell, mouth and internal organs, and has settled out of the water column to the bottom of the tank. Most importantly, the crabs looked like a crab – albeit miniature ones.

“In 2009 and 2010, our methods allowed us to increase glaucothoe survival to 50 percent, and juvenile survival to 20 percent” says Daly. “In all, some 100,000 crab reached the juvenile stage in each of these years. We consider that to be reasonably good, but there is always room to improve.”

This year’s egg-bearing female crabs included 20 red king crab from Bristol Bay, 20 red king crab from Southeast waters, and 19 blue king crab from the Bering Sea around Saint Matthew Island. Local fishermen and the Alaska Department of Fish and Game collected the crab for the research program.

While Daly and Swingle continue to perfect techniques for hatching and raising red and blue king crab in the Seward hatchery, UAF scientists and graduate students in Seward and Juneau, and federal researchers in Kodiak and Newport, Oregon, have begun studies aimed at learning how hatchery crab might fare in the wild. Such studies include understanding the roles of habitat, crab body size, prey density, predator density, water conditions, and predator types on the survival of juvenile crab. Lab experiments are being done at the Hatfield Marine Science Center in Newport, Oregon, and the NOAA Fisheries Lab in Kodiak. Small scale field experiments are being conducted in Yankee Cove, near Juneau, Alaska.

And while a combination of state and federal grants have paid for most of the research to date, there is growing interest by industry in supporting the program.

“Fishermen and fishing organizations have supported this effort all along with substantial financial contributions, and by helping collect broodstock animals,” says McCarty.

In 2010, Santa Monica Seafood, one of the largest west coast seafood distribution companies, donated $10,000 to the research effort as part of their commitment to sustainable Alaska seafood.

And this year, a group of fishing industry interests donated $25,000 to the AKCRRAB program. They include the Bering Sea Fisheries Research Foundation; the Central Bering Sea Fishermen’s Association; the Aleutian Pribilof Island Community Development Association and the Groundfish Forum.

“The industry funds are especially important right now as we complete efforts to raise the king crab born this past spring to the first juvenile stage,” said David Christie, Director of Alaska Sea Grant. “This is the point at which the crab are shipped to various researchers for their experiments to learn more about crab habitat preferences, predator relationships and avoidance, and genetics, among other things.”

“These donations are all significant because these groups are key players in the Bering Sea crab fishery,” says Arni Thomson, who for years was the executive director of the Alaska Crab Coalition, but recently signed on as president of the United Fishermen of Alaska (UFA). UFA is the umbrella group that represents 37 commercial fishing associations that engage in fisheries harvests in Alaska’s state and federal waters.

There remains a great deal of research to be done before state and federal fisheries managers might consider a pilot program to release hatchery born crab into the wild.

Alaska Sea Grant Director David Christie said three key components of the research program must show progress before responsible management decisions can be made about launching a large-scale hatchery effort.

“Hatchery scientists need to continue work to expand the limited production techniques they use now to successfully and economically produce very large numbers of crab that would be needed to enhance the low wild populations,” explains Christie.

Christie also said research is needed to answer questions about when, where, and how best to release hatchery crabs. Such research has already begun, he says, but it needs to grow and to gradually expand from the lab into the field. Also underway is research to answer questions about the genetics and distribution of wild crab stocks to ensure that any breeding program will not adversely affect the viability of wild stocks.

They are questions for which university and federal biologists in Fairbanks, Seward, Juneau, Newport, and Kodiak, are eager to find answers.
To learn more about the Alaska King Crab Research, Rehabilitation and Biology program, please visit:

Doug Schneider is the Science Writer and Information Officer with the Alaska Sea Grant College Program at the UAF School of Fisheries and Ocean Sciences.

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