Fishing crews have started to head back to the ocean to catch opilio crab.

All of the rationalized crab fisheries, except one, opened Oct. 15. The traditional Bering Sea snow crab season however, opens in early to mid January.

So far, only a few fishermen have started fishing for snow crab.

“We’re just now starting to see people gearing up and going fishing,” Bering Sea/Aleutian Islands area management biologist Forrest Bowers said. “Right now, there are 12 that are fishing, and potentially about 84 more that could fish.”

There were a total of 96 preseason registrations before the September deadline, but Bowers said normally about 70 boats participate. He expects most of the fishing to be finished in April.

“Most of the fishing will be wrapped up by the end of March, middle of April, provided that weather conditions and sea ice don’t cause too much of a problem,” Bowers said.

The 48-million pound quota for fishermen this year is down from last year’s 58.5 million pound limit. The community development quota was allocated 4.8 million pounds, and the remaining 43.2 million makes up the individual fishing quota for the bulk of the fleet.

To determine quota an annual stock assessment process is conducted each year using surveys and population dynamic models to measure abundance of stock.

“It is a quite extensive federal and state stock assessment process,” Bowers said.

Since stock assessments decreased, the total allowable catch had to be lowered. Bowers said this isn’t an uncommon trend.

“Snow crab stock fluctuates quite dramatically from one year to the next,” he said. “It’s not unusual to see changes even larger than this. A change in 10 million pounds would almost be considered stability.”

There are a number of factors that can cause populations to drop including variations between surveys. Even if the measured population stayed the same two years in a row, the survey may be different.

Environmental factors like predation, water temperature and prey availability may also affect population size.

“It’s hard to pinpoint one thing or the other,” Bowers said.

Mirror writer Louis Garcia can be reached via e-mail at lgarcia@kodiakdailymirror.com.