April 10, 2007
Tuesday

NOAA researchers have turned their eyes, experience and microscopes on a rare specimen: a huge female shortraker rockfish, Sebastes borealis, donated for science by Michael Myers, a factory manager on Trident Seafood's catcher-processor Kodiak Enterprise.

Dr. Chris Wilson of NOAA's Alaska Fisheries Science Center holds a 38-inch ruler up to a giant shortraker rockfish caught in the Bering Sea near the Pribilof Islands. Photo: Karna McKinney/NOAA Fisheries

The huge rockfish was one of about ten rockfish accidentally scooped up by fishermen in a net that brought in around 75 tons of pollock, Myers explained.

They caught the rockfish in mid-March when the Kodiak Enterprise was trawling at about 350 fathoms in the Pribilof Canyon at night just south of the Pribilof Islands in the Bering Sea. Catcher-processors in the Bering Sea are allowed to retain a small percentage of their targeted pollock catch weight in shortraker and rougheye rockfish which are sometimes caught accidentally in the large mid-water trawls.

Myers explained that the crew alerted him about the huge creature. He told them to freeze the big rockfish whole.

The shortraker rockfish Myers had frozen is 112 centimeters (about 44 inches) long and weights almost 27 kilos (almost 60 pounds). While that's a truly huge shortraker rockfish, it's not a record. The book 'Fishes of Alaska' (Mecklenberg) cites a maximum known size of 120 centimeters (about 47 inches), and another at 116 centimeters (about 46 inches) reported caught off eastern Kamchatka in the early 1990's.

"We're grateful to Mike Myers and Trident Seafoods for giving this huge specimen for research," said Alaska Fisheries Science Center Director Doug DeMaster. "We are gathering scientific information from her."

But the NOAA scientists aren't the first non-fishermen to get a look at the frozen rockfish. Myers first took the fish to his sons' grade school, Immaculate Conception Our Lady of Perpetual Help School in Everett, Washington. Myers said that while the students were fascinated (and one younger student was frightened) by the rockfish, the students "didn't go quite as crazy over it as the researchers" at the Alaska Fisheries Science Center in Seattle.

Researchers have carefully measured, photographed and documented the specimen. They have removed an otolith (ear bone) from the giant rockfish and from the otolith have estimated the fish's age between 90 and 115 years. Otoliths contain growth rings--similar to the growth rings on the trunks of trees--which allow scientists a method for estimating age.

Researchers are also taking tissue samples to study the fecundity of the rockfish, and are analyzing the stomach contents.

Source of News & Photograph:

NOAA's National Marine Fisheries Service (NOAA Fisheries)
www.afsc.noaa.gov

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