The half-inch-long krill may not appear on restaurant menus nor stir much talk of special protections like, say, salmon or rockfish. But federal regulators think restricting the catch of the shrimp-like crustacean may be just as important.

The National Marine Fisheries Service, which has recently enacted restrictions on chinook salmon and several species of groundfish, is now considering an outright ban on krill fishing off the coasts of California, Oregon and Washington.

Currently, no large-scale krill fisheries operate on the West Coast of the U.S., and there's little immediate concern about krill numbers. But regulators are heeding warnings from researchers in Santa Cruz who say a future dip in the krill population could have dire consequences for the wide array of marine life that feeds on krill -- from seabirds to migratory whales to popular commercial fish.

"Regulation seems like a good, proactive way to help current stocks [of other fish]," said Mike Burner, with the Pacific Fishery Management Council, which advises the National Marine Fisheries Service. "And by preserving this forage you might have the opportunity to prevent some of the deviations seen in stocks like salmon."

Public comments on the proposed ban are under review, and with few concerns to address, Burner expects the prohibition to be in place by the end of the year.

The call for krill protections is fueled by a growing international krill industry. In places like the Monterey Bay National Marine Sanctuary, researchers have been pushing for restrictions since the beginning of the decade.

"Krill is being fished in other areas, and the possibility for a fishery to develop [here] is real," said Baldo Marinovic, a research biologist at UC Santa Cruz who studies krill. "Of course, the best way to regulate a fishery is establishing regulations before there are any stakeholders."

Though krill is found all over the globe, large fisheries exist only off the coasts of Japan and Antarctica. Krill is fished for food in some countries, but is more commonly used for bait and increasingly aquaculture, where demand is expected to grow as fisheries worldwide struggle.

In recent decades, smaller krill harvesting operations have begun as close as British Colombia.

While California law bans krill fishing up to three miles off the coast and prohibits off-loading of krill in state ports, it doesn't safeguard open waters from fishing.

That's what led Monterey Bay Sanctuary officials, along with Marinovic and UCSC colleagues Don Croll and Bernie Tershy, to press the Pacific Fishery Management Council for more extensive regulations in 2004.

In 2005, the Pacific Fishery Management Council responded by drawing up a proposal to ban krill fishing three to 200 miles off the entire western seaboard. The plan was initially held up by the federal Office of Management and Budget to work out details, but returned to the table late last year.

Marinovic and his colleagues say during normal years, the planet's large krill population is not likely to suffer from continued fishing. But a severe change in ocean conditions, like with temperature or currents, they say, could unravel a complex chain of marine life that starts with krill.

Krill feed on phytoplankton, and in doing so, pass key nutrients to their predators which, in turn, pass them on to their predators.

"If there were krill boats harvesting during a stressful time, they'd have a huge impact on other animals," Marinovic said.

The UCSC researchers estimate that West Coast commercial fisheries relying on krill, which include salmon, squid and hake, are worth more than $5 billion annually. In addition, eight species of endangered marine mammals, including the blue whale, and two species of endangered seabirds are supported by krill, according to the researchers.

"This [proposal] is an all-too-rare example of getting out in front of marine issues before there's a crisis," said Kaitilin Gaffney, a program director with the Ocean Conservancy and member of an advisory committee to the Monterey Bay Sanctuary. "You can't wait for a crisis before you take action."

Contact Kurtis Alexander at 706-3267 or kalexander@santacruzsentinel.com.