With a new halibut season cranking up in Southcentral, anglers pursuing the big, tasty flatfish should keep one word in mind.
Small.
While halibut will never be confused with hooligan, the average weight of a sport-caught flatfish has slipped 26 percent over the last dozen years to just 15 pounds, according to the Alaska Department of Fish and Game.
Even the state's richest fishing tournament, the Homer Jackpot Halibut Derby, which began Sunday, saw the third smallest winner of its 25 years last summer, a 278-pound flatfish caught by Jesse Olvera of Fairbanks.
Shrinking too is the size of the halibut charter fleet in the wake of a new National Marine Fisheries Service rule that will scuttle 154 Alaska boats who don't qualify for the new federal permit.
But so far at least, Southcentral anglers' bag limits have avoided shrinkage problems that have plagued their Southeast angling brethren who are restricted to just one halibut per day.
"There has been a long-term decline in the growth rate of halibut," said Homer biologist Scott Meyer, a halibut expert with the Alaska Department of Fish and Game. "Fish are smaller because they are growing more slowly."
Similar stunted growth happened back in the 1920s and 1930s, he noted.
"There are plenty of big halibut out there, but this is different because they've documented a change in the growth rate -- and there has been quite a bit of speculation about what is causing the decline. The jury is still out."
There's no shortage of suspects, according the Steven Hare of the International Pacific Halibut Commission, who noted that today's 15-year-old female halibut averages about 30 pounds, less than a third of what a female of the same age weighed in 1975.
His leading theories include:
• Removal of some of the larger and typically fastest-growing halibut by commercial and sport fishermen, called size-selective fishing, reduces those traits in the population over time.
• Anglers repeatedly tossing back smaller halibut searching for a tophy kills some flatfish. About 18 percent of the released halibut don't survive, Hare said.
• There are more halibut in the seas than there were in the 1960s or 1970s. At the same time, the population of the rarely fished arrowtooth flounder, which occupies similar terrain, has exploded. The result is crowding and severe competition for food.
• Some unknown problem has harmed the quality or quantity of halibut food.
"Arrowtooth flounder are now the most abundant fish in the Gulf of Alaska in number of fish and biomass -- and they not targeted by the commercial fishery," said Jon Warrenchuk, the Juneau-based senior marine scientist at Oceana, the international ocean conservation organization.
Unfortunately, arrowtooth flounder flesh is the opposite of firm and tasty halibut, difficult to make into surimi, the popular imitation crab-flavored sticks common in grocers.
But on Homer Spit on Sunday, a new derby was starting and before nightfall happy anglers were lugging fresh fish filets.
Happiest, perhaps, was Jean Manson. By landing a 90-pound halibut aboard Pete Wedin's Alaska Experience boat, the California woman got to see her name atop the derby leader board for 24 hours.
And that's just how long it lasted before Shane Brooks of Homer brought in a 121-pounder on Monday to bump Manson.
Already, a big three-digit fish was on the board -- a fish that may be on contention to win monthly prize of $1,000 for May's biggest fish. Even if Brooks had tossed the fish back, he could have wound up with a $1,000, the prize delivered after a month-end drawing among anglers returning 60-pound-plus halibut, mostly females, to the sea.
With the sport fishery taking only about 15 percent of the total halibut harvest, it's a small step, but a step towards preserving a popular fishery.
"They're the apex predator of the sea floor," Warrenchuk said. "We can't afford to see them decline."
Reach reporter Mike Campbell at mcampbell@adn.com or 257-4329.
Shrinking halibut
The average weight of Alaska halibut caught by sportfishermen:
Year Number Pounds
1995 233,049 19.4
1996 251,769 18.8
1997 272,366 20.2
1998 249,244 18.9
1999 231,224 18.3
2000 288,036 18.4
2001 253,598 18.4
2002 242,848 17.3
2003 281,633 19.3
2004 332,168 16.9
2005 333,988 17.0
2006 319,002 16.7
2007 402,471 15.6
2008 343,394 15.5
2009 317,804 15.0
Source: Alaska Department of Fish and Game
By MIKE CAMPBELL
mcampbell@adn.com