Saltwater fishery officials are reporting a resurgence of a mysterious condition that's bound to turn the stomachs of fishers -- mushy halibut syndrome.
Although the condition that turns the normally firm, good tasting and pricey meat of halibut into mushy pulp isn't new, Alaska Department of Fish and Game's Barbi Failor said the department is receiving more reports of mushy fish caught by sport fishermen "with pretty regular occurrence" all over Cook Inlet.
The reports have prompted officials to conduct a round of tests to determine what might be causing the condition and to see if it's spreading.
"The reports seem to be coming from just about everywhere," she said.
Although Failor said mushy halibut meat is safe to eat and tastes no different than regular halibut fillets, it has a "jelly like" consistency and when it is cooked falls apart into an "oatmeal."
However, Failor said Fish and Game still isn't sure why.
"That's part of the problem -- we're not sure what's causing it," she said.
Officials started receiving complaints about the condition again this year when the lower Peninsula halibut fishery started gearing up in late May. The reports are mostly limited to Cook Inlet waters -- reports aren't coming in from other halibut fishing grounds like the reefs near Montague Island, Prince William Sound or Nuka Bay located on the southern tip of the Kenai Peninsula. Failor said a few reports have come in from Kodiak fishermen, but nothing to the scale of Cook Inlet.
Failor wouldn't venture a guess as to the rate at which the syndrome is affecting halibut. However, symptoms appear most often in small halibut between 15 and 20 pounds, she said.
As a result of the concerns, Fish and Game has taken several samples to a pathology lab and officials suspect the problem is a nutritional myopathy, which is a breaking down of muscle fibers and tissue.
Ted Meyers, Fish and Game's chief fish pathologist, said no evidence has been found to indicate the condition is infectious from halibut to halibut, but he didn't completely rule it out.
"There's no protozoa, no bacteria, no apparent infectious agent," he said. "... But again, we don't know."
Meyers said Fish and Game hasn't received many reports of the condition from commercial fish processors -- just sport fishing.
"It makes me think that it might be fairly localized and may be a smaller number of fish that are just being more noticed because they are on a charter boat and people would like to keep those fish and can't or don't want to," he said. "I would certainly think that if it were a major problem then the commercial processors would raise a red flag."
More nutritional studies are planned this summer and Failor said staff hopes to have more of an answer by the fall.
"If we don't have a better idea, at least we will be able to rule some things out," she said. "It is a big ocean out there so narrowing it down could be challenging."
Meyers said the condition looks like a vitamin E and selenium deficiency based on pathologies in other animals where that deficiency has occurred.
Beyond disappointed fishermen, Failor said the condition could affect how halibut behave because the fish is essentially a "big muscle."
"That's how they move around, that's how they get their prey, that's how they function, essentially," she said. "If you can think about it as the muscle fibers breaking apart and breaking down that means they are not able to swim and that means they're not able to get prey."
Meyers said the condition might also be caused or inflamed by interspecies competition for food, most likely with the arrowtooth flounder.
"So conceivably this could be connected somehow to a nutritional deficiency if there's a tremendous amount of competition going on between these two species, especially in the earlier life stages, although we see mushy halibut in older fish as well as younger fish and there doesn't seem to be a difference between male or female," he said.
Meyers said fishermen have been finding more crustaceans in the stomachs of the mushy halibut than their usual diet of forage fish.
"One would always think crab would be pretty nutritious but maybe it is not for halibut -- I don't know," he said.
If the cause of mushy halibut syndrome is indeed nutritional, it would not be an easy fix, Meyers said.
"Right now we are definitely aware of the issue," Failor said. "If people feel like they need to report it then I am not going to discourage them from doing that, but we know it is going on and it is something that we're looking into."
Brian Smith can be reached at firstname.lastname@example.org.