Just when the demand for sashimi escalates in the holiday season, the supply is likely to shrink, thanks to a new international fishing quota that will kick in next month.

The limit on bigeye tuna, a premium ahi source, is set at 10 percent less than the 2004 catch under a decision by a 16-nation commission seeking to control overfishing of the species in the central and western Pacific.

The 125 Hawaii-based longline fishing vessels are limited to a total of 3,763 metric tons — 8.3 million pounds — for the year ending Dec. 31 under the action of the Western and Central Pacific Fisheries Commission. That quota may be reached “;near the middle or end of December,”; said Charles Karnella, international fisheries administrator with the National Marine Fisheries Service, Pacific Island Regional Office.

It will send fishermen farther afield to seek the prized catch, which, according to a fresh-fish retailer, raises concern about not only price but the quality of fish sold days after it is caught.

It is not goodbye to ahi sashimi, said Sean Martin, president of the Hawaii Longline Association and president of Pacific Ocean Producers. Yellowfin tuna is also ahi, and it is not covered by the quota.

He said local fishing boats can fish for bigeye tuna by sailing about 150 miles east of Hilo to cross the eastern boundary of the western and central Pacific fishery zone at 150 degrees west longitude. “;It is a common area for us to fish — about 35 percent of the fleet is there today anyway,”; Martin said. The eastern Pacific fishery is administered by a different agency and “;that area quota is nowhere approaching closure. So there will be fish available during the holidays. The fleet is working on strategies so the supply will be consistent.”;

Brad Pulice, president of Fort Ruger Market, said he expects the quota “;will have a huge impact on fish availability and quality,”; adding, “;What it means is that by the time fish gets to the auction block, it will have been sitting in their boats for a longer time. I suspect we will see a lower-quality fish at a higher price. The unfortunate reality is that we can try to control costs but most of the cost will be passed on to the consumer.”;

Pulice said bigeye tuna sashimi now sells for $22 to $26 a pound, depending on the quality.

The fish market owner said, “;It's unfortunate the quota has to be enforced for the calendar year. If they did it for the fiscal year, the impact would be in the summer when it doesn't matter as much to consumers.”;

Karnella said the final draft of the administrative rule setting the longliners' quota won't clear the hurdle of legal review in Washington, D.C., and go into effect until about the same time as the maximum catch is reached.

He said tuna fishing vessels are required to keep logs of their catch and the fisheries service has contracted observers aboard about 20 percent of the vessels at any time.

The population of bigeye tuna in the Pacific is being reduced at a rate that threatens replenishment of the stock, said Paul Dalzell, senior scientist with the Western Pacific Regional Fishery Management Council.

Overfishing is partly the fault of purse-seine fishing vessels targeting skipjack tuna for the canned tuna industry. The United States has the largest fleet of ships that use devices that attract juvenile bigeye tuna and other species besides skipjack.

“;The situation got so bad, the catches are about twice the level of maximum sustainable yield,”; Dalzell said.

The multination commission set different quotas for different countries and various arrangements are made to offset the quotas. For example, China makes arrangements with South Pacific islanders to share their quotas.

“;Of course, it's not fair,”; Dalzell said. “;The American fisherman ... does not operate on a level playing field. The Hawaii fishermen are environmental heroes. They have done so much to assist in the science of ecosystems based on management and collaboration with scientists. The Hawaii fishery is the exemplar for environmentally responsible fishing. Other fisheries are trying to emulate it.”;

Martin said that “;a fair amount of fish imported into Hawaii was caught by foreign fleets fishing in the same area who are not under the same quota restrictions. There are imports sold here every day.”;

Island longliners will face bigeye tuna quotas for the next two years that are 10 percent below the 2004 benchmark harvest.