Scientists made progress last week on a model that will help estimate the population of Aleutian Islands golden king crab.

When it’s finished, the model will let fisheries managers decide each year how much crab can be harvested sustainably.  That could translate into millions of dollars of additional revenue or cuts for the fishery, depending on what the model shows.

Right now, the State Board of Fisheries sets the golden king crab harvest in regulation, as opposed to annually.  It's hovered around 6 million pounds for the last decade.

Doug Pengilly is a biologist with the Alaska Department of Fish and Game.  He’s working on the model, which has been in development for a while.

“The Aleutian Islands golden king crab stock assessment model is a pretty tough challenge.”

Pengilly says that’s because most of their data comes from fishermen, so it isn’t standardized.  For example, one of the datasets they’re using is catch rate – the number of crab pulled up in each pot.  It seems like that would be a pretty good measure of abundance – the more crab in each pot, the more crab in the ocean - but of course, it’s not that simple. 

Different fishermen let their pots ‘soak’ for different amounts of time.  The ones who soak their pots for longer might get more crab per pull simply because their pots have been in the water for more days.

Pengilly says the workshop helped them figure out how to better incorporate that kind of data, but the model still has a ways to go before it’s completed. 

Pengilly and his colleagues will present an updated data analysis to the North Pacific Fishery Management Council’s Crab Plan Team in May.  In July, Fish and Game will do their tri-annual pot survey of Aleutian Islands golden king crab.  Pengilly says he’s hoping they can take advantage of some new technology to make the survey more accurate.

“It’s certainly improved in the last… well since it started in ’97, in terms of knowing exactly or at least a pretty good idea of where we’re setting these pots, the depths we’re at.  It’s pretty hard to do this in the Aleutians because you’re doing it on these mountain slopes basically.  But we have more equipment now than in ’97.”

Until the model is completed the Board of Fisheries will continue to set the harvest level.  There’s a proposal on the agenda for their March meeting to raise the golden king crab quota for 2012-13 based on fishermen’s observations of recent high catch rates.