Ever caught an arrowtooth flounder when you were hoping for halibut? Ever had to face the prospect of tossing back your long-awaited catch or cutting your losses and using the flounder for bait?
Cheryl Barnes, a PhD student at the University of Alaska Fairbanks, wants to put the fish to good use — and figure out why flounder are gaining on halibut in the first place.
She wants their carcasses. Specifically, their stomachs.
Posters reading “Stomachs Wanted” have been popping up around Juneau. They request both Pacific halibut and arrowtooth flounder stomachs, either fresh or frozen. Donators are asked to record the fish’s capture date, location and depth, as well as its total length and body weight.
Barnes sat down with the Empire at Gonzo’s, overlooking Statter Harbor in Auke Bay, to explain why she is making the unusual request: for a study to determine the cause of the shrinking population of Pacific halibut and the increase in arrowtooth flounder.
“In the late 80s, an average 20-year-old female halibut weighed about 120 pounds, and now-a-days, that same 20-year-old female on average is weighing 45 pounds,” Barnes said from across the table. “There is a huge reduction in spawning size biomass. This is a concern for the fishery.”
As for the reason, currently, “people think it’s either removing those larger faster growing fish from the population… Another is environmental variation, so potentially because of changes in temperature, in prey availability, we’ve seen reduced growth rates of halibut. Another thought is this idea of competition either within the species with other halibut in the Gulf of Alaska or with species like arrowtooth flounder, which has skyrocketed in abundance in the past few decades, increasing 500 percent in the number of arrowtooth in the Gulf. People think that because of their increased abundance, maybe they’re competing with halibut for either space and/or prey — reducing growth rates in halibut.”
Barnes said the flounders’ biomass has surpassed that of pollock in the Gulf of Alaska, which concerns fishery scientists. People fish for halibut often, but not arrowtooth, which are considered unmarketable.
“(Arrowtooth flounder) have really soft flesh that when you heat them up they just turn into a fish smoothie, so nobody wants this fish. Everyone avoids them like the plague – but they’re everywhere!” she said.
Barnes plans on using both data previously collected in the gulf and information from her study to find the reasons for the decline of halibut.
“We’re collecting stomachs from halibut and arrowtooth to see if they’re eating different things, and we’re also interested in collecting information about where these fish are caught,” she said. The location can help them figure out if halibut are eating different things where they’re more abundant than arrowtooth, versus where arrowtooth are more abundant than halibut.
Barnes said she and her assistants collected about a thousand stomachs last summer and hope to get a similar amount this year. If someone is interested in donating a stomach or a stomach within the fish, all they have to do is contact Barnes and either she or one of her assistants will go collect the fish.
She said besides the different texture of the meat, arrowtooth and halibut can be differentiated by the flounder’s larger mouth to body size ratio along with its “gnarly” looking teeth.
“A stomach isn’t really useful unless we know the species and the length of the fish,” Barnes said, emphasizing the need for these two details to be recorded over all else.
Barnes said she doesn’t expect people to start donating until June and July. Donations will conclude in September.
Barnes’ study is funded by the Pollock Conservation Cooperative Research Center.
Barnes can be contacted at (907) 957-4893 and cheryl.barnes@alaska.edu.
• Contact Clara Miller at 523-2243 or at clara.miller@juneauempire.com.
