[env-trinity] Chinook Runs in Central Valley Down- Krill Absent

Tom Stokely tstokely at trinityalps.net
Thu Nov 1 10:42:35 PDT 2007

Chinook salmon shortfall puzzles anglers, experts; The numbers of fish returning are far below expectations
Sacramento Bee – 11/1/07
By Matt Weiser, staff writer

For fishermen and biologists, fall has become a season for fretting in California.


For the second year in a row, spawning fall-run chinook salmon are not returning to the Central Valley's rivers in the numbers that anglers and experts anticipated, touching off what may be a record year for nail-biting and hand-wringing.


"Horrible. Slowest year in their lifetime. Never seen salmon fishing this bad," said Ron Howe, summing up the feelings of many salmon fishermen this fall. He has pursued the mighty chinook, also known as king salmon, in the American River for 17 years. 


"Everybody's saying the same exact things. This is just unbelievable that the fishing's so poor," he said.


Hard numbers on the American River are difficult to come by until the run is over at the end of the year, said Terry West, manager of the state fish hatchery at Nimbus Dam. That's because there is no way to count natural spawners in the river.


But the 11th Annual American River Salmon Festival, held Oct. 13 and 14, offered one sad indicator. There were no salmon climbing the hatchery's fish ladder that weekend, normally the festival's star attraction.


West managed to collect just 22 fish in five hours – compared to 120 in prior years – just to put some salmon in a big tank as a display for festival-goers.


He said he has never seen so few salmon in the river at festival time.


"We're kinda lucky we caught enough," he said. "I try to always have a positive outlook on Mother Nature. So I'm going to continue that until I get all the figures in."


The most reliable running tally of spawning chinook in the Central Valley comes from the Coleman National Fish Hatchery on Battle Creek, a Sacramento River tributary in Shasta County.


Through Oct. 24, about 20,700 chinook returned to Battle Creek to spawn. That's only about 20 percent of average for that date compared to the previous four years, according to state Department of Fish and Game records.


The numbers baffle experts and laymen alike, because all indicators are that this fall should produce a vigorous salmon run.


"We just don't understand why there aren't more fish around," said Roger Thomas, who has run salmon fishing charters out of Sausalito since 1968. "We had some lean years in the 1970s, but this kinda looks like the leanest in a long, long time. All of us are seeing the same conditions and share the same concerns."


Regulations limited the commercial salmon fishing in the ocean the past two years, which should have left more fish to return upriver.


A strong, cold upwelling in the Pacific Ocean this summer also produced ample food along the California coast, resulting in a bumper crop of herring, sardine and anchovy, said Frank Schwing, director of environmental research at the Southwest Fisheries Science Center in Santa Cruz, a division of the National Marine Fisheries Service.


But there's a gaping hole in that news: Schwing said the population of krill has mysteriously crashed in the ocean. This zooplankton, which resembles a tiny shrimp, is a key salmon food.


Several bird species that depend on krill have also crashed, Schwing said, such as the Cassin's auklet, a seabird that nests on the Farallone Islands. Also, whales that normally gorge on krill shifted to eating fish.


"Historically there's a strong relationship between abundance of krill and the amount of upwelling that occurs," said Schwing.


"But this year that model has broken down for some reason."


Everyone recognizes it's still early in the fall run, said Allen Grover, a biologist who monitors the ocean salmon fishery for Fish and Game. The run normally continues through December and even into January, and it's normal for the run's peak to shift each year.


"I'm concerned, but it's too early to say 'Sell your boat,' " said Grover. "Trying to correlate oceanographic events to fish survival is pretty hard to do."


A combination of plumbing problems in the Central Valley may also be hurting the run this year. State and federal water managers had to slash water exports from the Sacramento-San Joaquin Delta early this summer to protect the Delta smelt, a threatened fingerling.


This put water deliveries to cities and farms behind schedule, forcing water officials to ramp up reservoir releases for most of the summer.


This, combined with a drought year, left many of the state's reservoirs with below-normal storage, including Folsom Reservoir, which feeds the American River.


A question lingers as to whether the water left behind the dam is still cold enough to trigger the salmon run. The fish need water at 60 degrees or colder to start migrating. This week, those flows are leaving Nimbus Dam at around 63 degrees, said West.


For now, anglers are hoping the best of the run is still to come. Veterans say anglers can still find salmon in the ocean and rivers: Howe hooked three and caught two in two days on the American River this week, both over 20 pounds.


But they'll need to balance their worries with fistfuls of those other fishermen's friends: luck and patience.


"Normally I would hook over 50 fish in the last two days, and I hooked three," said Howe. "And I was lucky to do that, because other guys were out there not hooking any." #



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