Md. firm aims to keep salmon in the pink New pigment tested for captivity-bred fish


CAMBRIDGE -- Make-it-pretty maven Martha Stewart would love this: scientific research aimed at making salmon pink.

Salmon raised in captivity aren't pink. They're white.

"In nature, salmon eat a lot of crustaceans that have a lot of pigment," explains Reginal M. Harrell, a marine biologist at the Center for Environmental and Estuarine Studies at Horn Point. "The consumer's not going to want to buy a salmon that's white."

Without the crustaceans, captive salmon are getting the pigment -- called astaxanthin -- from a synthetic additive made in Germany and added to fish food.

Harrell and a small Columbia-based company called IGENE Biotechnology Inc. would like to change that method. So Harrell this week began a yearlong test of a natural form of astaxanthin mixed with yeast, which the company has registered under the trade name of Astaxin.

On Tuesday, he and three other researchers at CEES set up a dozen tanks in a hatchery at Horn Point. Each tank houses 34 captive-bred Atlantic salmon, each one about 14 months old and weighing a quarter of a pound. "This is the salmon that you find in the grocery store," Harrell said. Behind him, two graduate students were filling the tanks with the fish, then pulling nets over the tanks to keep the salmon from jumping out. "Market size is usually about 1 1/2 pounds and up."

His fish should be about that size when the experiment ends early next year. Three tanks will be fed regular fish food with no pigment additive. Three will get the minimum amount of Astaxin required to produce the desired pink result. Three will get five times the minimum, and the final three will get 10 times the minimum.

But these little salmon won't go to market. Instead, they will be sent to fish pathologist Renate Reimschussel at the University of Maryland at Baltimore. She will analyze tissues from each fish, checking to see what effect, if any, normal and increased Astaxin levels have on fish size, health and pathology.

Pathology tests

Pathology tests will also be run on sample fish as the study progresses, to check for any cumulative effects from Astaxin. "We already know the fish will be pigmented," says Harrell.

Will the fish with the most pigment added be the pinkest?

No, they'll all be about the same color, no matter how much pigment they had, says Harrell. "It won't be like a blush-colored wine vs. a blood-red heart," she said.

The yearlong fish study will cost $96,584, Harrell says. About two-thirds came from a state grant; the balance from IGENE. The fish food with Astaxin added was produced and donated by Perdue Feeds Inc.

After the results are evaluated and recorded, IGENE plans to seek approval for Astaxin from the Food and Drug Administration.

"The pigment itself is already approved," says Stephen Hiu, IGENE's president. "We're trying to get the yeast approved."

IGENE, which specializes in fermentation research, began developing Astaxin a decade ago, he says, and has put millions of dollars into it.

If it is approved, there will be plenty of fish to eat it. In 1994, according to Scott Smullen at the National Marine Fisheries Service in Silver Spring, farm or pen-raised salmon accounted for 24.7 million pounds of the harvest. (By contrast, wild salmon of all varieties weighed in at 901.1 million pounds, he says.)

VTC Hiu hopes that his company can successfully market Astaxin for the salmon market. But he sees even broader applications for it down the road.

'Natural aspects'

"We would emphasize the natural aspects of it," he says, contrasting his product with the German synthetic additive now used for farm-raised salmon. Ultimately, he hopes, it could find its way into food colorings and cosmetics.

Although Maryland's aquaculture industry is unlikely to expand into salmon, which require colder weather, Astaxin could still benefit the state, says Brad Powers, assistant secretary of the Department of Agriculture.

Salmon are not the only fish where pink is preferred, he says: Red-meat trout fetch higher market prices than regular trout. Astaxin could be fed to trout, which are raised in Maryland.

"They like that pink color," Powers says of fish-buyers.

Pub Date: 2/14/97

Baltimore Sun Articles
Please note the green-lined linked article text has been applied commercially without any involvement from our newsroom editors, reporters or any other editorial staff.