The International Pacific Halibut Commission, which regulates halibut fisheries in U.S. and Canadian waters, is set to take a fresh look at the minimum size limit for commercial fisheries during its meeting cycle this winter. The current limit allows commercial fishermen to retain fish larger than 32 inches, but the size of mature halibut has been shrinking over the years, which has some wondering whether the limit should be reduced or removed altogether.
Since the 1990s the size of mature halibut has been falling.
“Now their average size at age for halibut is approximately what it was in the 1920s and 1930s,” Steve Keith said, assistant director of the International Halibut Commission, or IPHC.
Keith adds this is not the first time the commission revisited the size limit, which was set at its current level in 1974. The IPHC analyzed the possibility of reducing or eliminating the size limit back in 2015, but ultimately decided against making any changes.
The limit is supposed to be a safeguard for spawning fish. The idea is that if halibut are larger than 32 inches, they’re likely to have spawned, keeping future fish stocks healthy.
“So, the question now is could you reduce the size limit and still have the same protection of the spawning biomass, but get some more yield out of the fishery?” Keith questioned.
The commission released a new paper on the topic in August. The analysis estimates that if the commission ditched the current size limit and fishing behaviors remained the same, the total catch across all districts would see a small 4-percent bump.
“The amount of the retained catch doesn’t change very much, but the makeup of the catch would change,” Keith explained. “About a quarter of it would be fish under 32 inches.”
He adds that any changes in fishing behavior depends on what’s happening in each district.
The Gulf of Alaska has seen the largest reduction in the size of mature fish compared to other regions, which may make targeting smaller fish more advantageous, but fishermen in the western Aleutian Islands are continuing to pull in larger fish. So, it may not be economical to target halibut under 32 inches in those districts.
Homer-based commercial fisherman and President of the North Pacific Fisheries Association Malcolm Milne currently fishes in the Gulf and has fished in the Aleutians in the past. Milne says despite catching smaller fish over the past two decades, he’s been in favor of keeping the current size limit.
“At the time, I came away with the idea that it wasn’t a good idea, that we would save more keeping those fish in the water and letting them grow,” Milne said.
He also says he’s been landing more fish above the 32-inch threshold over the past few years, but he adds that size isn’t the only consideration.
There’s plenty of concern over what processors would pay for smaller halibut.
“The marketability of the fish has always been a question too. Would that mean there would be a decrease in the value of a fishery if you started harvesting the fish?” Milne wondered. “But that’s obviously a secondary concern to the overall health of the biomass and what we’re removing from the water.”
The new analysis also estimates the mortality of undersized fish that are tossed overboard.
Mortality rates are measured in pounds. The analysis estimates that about 1 million pounds of undersized fish die in the Gulf of Alaska and Aleutian districts, and it estimates another 5 million pounds survive after being caught.
“Always a tricky one to decide what happens to a fish when you throw it overboard. Certainly the way we release them, I don’t run a bunch a gear,” Milne explained. “They seem very lively when we release them, but I think maybe bigger operations might be a little different. It’s a hard number to ever pin down.”
Milne notes that he will keep a close eye on the conversation as it progresses into the winter, but he says the idea is worth a fresh look.
The commission is set to examine the new analysis at its interim meeting in November and could have a decision on whether to make changes at its annual meeting in January.