Chinooks take biologists' bait
Fish passage plans seem to be working, but just how well remains to be seen
Alex Breitler
Record Net
11/14/2011
King salmon have returned to the Calaveras River, swimming through the heart of Stockton for the first time in four years.
And on this visit, they're finding the accommodations more to their liking.
Just east of Highway 99, crews have finished knocking out one of four major barriers which have often prevented the chinook from completing their voyage from the ocean.
Meanwhile, last year's heavy rainfall allowed officials at New Hogan Dam to release a special pulse of water earlier this month. The extra flow - nearly 10 times what would normally be in the river - alerted fish in the Delta that it was time to journey upstream.
Journey they did, swimming right under Pershing Avenue and past the University of the Pacific, all the way through urban Stockton.
It'll be weeks before experts know how many of the perhaps 3-foot-long fish made the trip. Kari Burr, a senior biologist with the Fishery Foundation of California, said this is the most salmon she's seen on the Calaveras since 2005.
"I just want Stockton to know they have chinook in their river," Burr said Wednesday.
How many of those fish will successfully spawn is another story.
The Calaveras is still a bit of a dead end as fish approach the foothill country. Many salmon are unable to flop over the top of Bellota Weir, east of Linden. That's a problem because the best places to spawn are above the weir.
Long-awaited plans to build a permanent $7 million fish ladder there are still on hold.
"It's really frustrating," Burr said. "Until that gets fixed, they're not going to get upstream."
What's more, extra flows to guide the fish aren't always a guarantee. During the recent drought that water would not have been available, says the Stockton East Water District, which diverts much of the river for farms and drinking water.
Regardless, when it comes to the often overlooked Calaveras, you have to celebrate the small victories.
"I think everybody's thrilled," said Kevin Kauffman, general manager of the water district. "The pulse flows we're putting down seem to be doing their job in attracting the fish."
Stacy Luthy, an assistant professor of biology at Pacific, had never seen a chinook in the Calaveras. She arrived at the university in 2007.
Last week Luthy deployed special sonar equipment just west of the university footbridge, and spotted the profile of what appeared to be a large salmon.
"It was amazing," Luthy said.
She and Burr then headed upstream to Budiselich Dam near Highway 99, where only a few weeks earlier crews finished building a rock ramp to help fish upstream. (In the past, salmon had to climb a steep pitch of about 7 vertical feet - a tall task, even for chinook.)
The biologists saw no fish, but it was clear salmon would be able to wriggle up the ramp.
So they went farther upstream, to Bellota, where they watched as salmon flopped their way onto the dam's concrete apron in what appeared to be futile attempts to get over the top.
Burr said she counted 45 attempts by fish to get over the weir in the span of about one hour. Two temporary fish ladders were placed there, but most of the fish didn't appear to be using them, she said.
Donnie Ratcliff, a Lodi-based biologist with the U.S. Fish and Wildlife Service, said there is some chance that the frustrated fish will reproduce even below Bellota. But there might be too many fish competing for a limited amount of quality habitat.
Stockton East has committed to improve passage at Bellota as part of a years-overdue habitat conservation plan. The plan has been sitting in the offices of federal wildlife regulators who have been busy with bigger rivers and bigger problems - like the deteriorating Delta.
Ratcliff said resolving the problem at Budiselich Dam is, at least, a first step.
