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Sinking number of Chinook salmon concerns biologists

The large blue-green and silvery Chinook salmon that fishermen hoped would pack the Merced River in fall and winter are doing just the opposite.

Their numbers appear to be dwindling at an alarming rate, say fishery biologists.

The count doesn't officially end until late December, and there's a chance the number of these fall-run salmon could improve, said Tim Heyne, senior biologist with the California Department of Fish and Game. But there's enough information now to give scientists reason for concern. "We've been concerned for years," he said.

Fewer than 500 salmon are expected in the Merced River this year. Last year that number was 1,200, Heyne said.

At a Merced Stakeholders Meeting on Monday evening, fisheries biologists David Hu from the U.S. Fish and Wildlife Service and John Montgomery from Cramer Fish Sciences gave a presentation about the salmon's disturbing decline.

Hu described the situation as at "crisis level."

The problem isn't just in the Merced River. Numbers are also low in the Tuolumne and Stanislaus rivers. "Something's going on," Hu said. "The fish aren't doing well."

What exactly is going on is debatable. Researchers are exploring a number of explanations. Loss of habitat and murky water conditions often come to the forefront of the conversation.

Low water flows, high temperatures and toxic algae threaten the fishes' health, Hu said. "There's water quality issues -- some nasty things in the water," he explained.

Predatory striped and black bass can also take a bite out of the baby chinook salmon population. "The reality is, while everyone wants to point to one thing, it's usually a whole lot of reasons," Heyne said. "Clearly, it's become a more hostile environment, which leads to a decline."

Citizens at the stakeholders' meeting were worried by the information and asked what they could do to help.

The answer: not much.

Some past river restoration projects have been known to hurt the habitat rather than help. "Gravel is being taken out during projects, and what's being put back isn't necessarily right," Hu said.

Salmon use gravel to spawn. And they must lay their eggs in the proper sizes of fresh, clean gravel. If there isn't enough gravel, there won't be as much spawning.

And not as much spawning leads to lower numbers of fish in the future.

"The irony is, the farmers who want to help by putting gravel back found out it would cost $14,000 for permits for a half-hour of work," said Pat Ferrigno, who owns land by the river. Fines were threatened if they did not get these permits before they did the work, she added. "We'll do it without people giving us anything -- we just don't want to be fined."

Nettie Drake, who led the meeting on Monday evening, agreed that there was a laundry list of government agencies to go through before citizens could try to help. Hu called the situation "bureaucracy at its finest.

"The intentions are good," he said in reference to the permits and the restoration projects. But, unfortunately for the fish, the outcome isn't always productive.

Meanwhile, biologists are crossing their fingers that there's more to the story. Heyne said there's a possibility the fish are just staying in the ocean longer than usual: "There are weird things that happen with fish. Just when you think you have it figured out, they do something late."

Chinook salmon spend can one to eight years -- although the average is three to four -- at sea before returning to streams to spawn, according to the Pacific States Marine Fisheries Commission.

But the San Joaquin River Delta has notoriously bad water, Heyne said. He listed problems with oxygen and ammonia. "There are so many factors negatively impacting them," he said. "They are stuck in a world where everything is turning hostile on them."

While more accurate counts of the fish won't bring them back, they can give scientists a better idea of the salmons' situation, Hu said. Salmon are recorded in the Merced River by tagging, release and carcass counting, which provide a sound estimate. "Chinook salmon tend to die after they spawn," he said. "It's sad, but good if you want to count them."

There is a lot of subjectivity to this method. Another method now happening on the Stanislaus River involves the use of a weir. The weir goes across the river, and fish swim through it as a camera shoots their pictures. "It counts fish by fish ... it's a great tool," Montgomery told stakeholders at the Monday evening meeting. "The Merced River needs a weir."

And more fish.

Reporter Dhyana Levey can be reached at 209 385-2472 or dlevey@mercedsun-star.com

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