With one of the world's valuable fisheries in a state of flux and fishermen at war, the International Pacific Halibut Commission convenes in Anchorage Tuesday to start a week of discussions on the fate of the big flatfish of the North Pacific.

At root, the problem facing the commission -- not to mention commercial, sport and subsistence halibut fishermen from the Bering Sea south all the way to California -- is simple: Not enough big fish to meet everyone's desires.

By and large, the halibut managed by the joint U.S.-Canada treaty organization are doing fine. There are plenty of fish, but most of them are now under 32 inches in length. Too small for the commercial halibut fishery, and even too small for many anglers.

Most want halibut 15 pounds and up. The average 32-incher weighs a little less than that. More important, though, those 32-inch-plus fish constitute what the commission calls the "exploitable biomass" estimated at 317 million pounds last year. It is now believed to be down to 260 million pounds, a drop of 18 percent in a single year.

This would not be alarming except for the fact that halibut from 32 inches up constitute the spawning population. The smaller, more plentiful halibut are sexually immature and incapable of reproducing. The commission needs to keep fishermen from catching too many of the adult fish until the younger fish mature, or the halibut population could crash.

Everyone agrees that would be a bad thing, but with the commission talking of drastic harvest cuts, there is plenty of fear about jobs. Commission scientists have suggested a 20 percent reduction in the catch may be necessary. That could force new restrictions on anglers and further reduce the halibut fleet and the shore-based processors that service the commercial fishermen. For years, the industry has been reeling from a slow but steady decline in halibut numbers and a big increase in consolidation of individual fishing quotas.

One commission report notes that when the North Pacific Fisheries Management Council led the National Oceanic and Atmospheric Administration into privatizing the fishery back in 1995, there were 2,206 boats actively fishing in Alaska, and 4,831 fishermen were given quota shares based on their past participation in the halibut fishery.

Many of those fishermen promptly cashed out of the fishery by privately selling their shares in what is still considered a publicly owned resource. According to the commission report, there are now only 2,740 quota holders -- a drop of 43 percent. Meanwhile, the number of boats fishing fell to 1,286 this year -- a decrease of 42 percent since 1995.

How this affects jobs is hard to say for certain. Individual, small-boat fishermen have been fading away, replaced by skippers with bigger boats and crews. The crews take up some of the jobs that once went to independent fishermen, but between the consolidation and reductions in harvest everyone agrees jobs have been leaking away in the commercial fishery.

The response has been for commercial fishermen to try to get the North Pacific Council, a body controlled by commercial fishing interests, to take fish away from charter boat operators to give to the commercial fishery. The commercial fishermen contend it isn't fair that the charter boats continue to operate under a fixed, guideline harvest while the catch limit for the commercial fishery keeps falling along with the shrinking halibut stock.

The commission reports an Alaska commercial catch for 2011 at 31.6 million pounds, still much more than the 5.9-million-pound sport catch. Charter anglers landed about 60 percent of that. And the sport catch was significantly less than the estimated 10 million pounds of halibut the commission says was caught and discarded dead by trawlers mining the Bering Sea and the Gulf of Alaska for Pollock and perch.

It was noted in commission reports, however, that the bycatch was "a 6 percent decrease from 2010 and the lowest since 1986."