Environment

‘Wild’ fish make a comeback in Putah Creek

Putah Creek, an often-muddy stream that meanders through Yolo County, has been through a lot in the past 150 years.

In 1871, settlers literally moved the stream by digging a new course to prevent flooding in the town of Davis. In the 1940s, the U.S. Army Corps of Engineers built levees along that course. In the 1950s, the U.S. Bureau of Reclamation blocked the creek with a 304-foot-high wall of concrete – the seventh-largest dam in California – to create Lake Berryessa.

Then in 1969, Creedence Clearwater Revival memorialized the creek in “Green River,” now a rock ’n’ roll classic.

Through it all, giant rainbow trout have somehow managed to thrive in Putah Creek. And earlier this month, the California Fish and Game Commission recognized that feat by designating the creek a “Wild Trout Water,” a distinction meant to ensure the creek always remains healthy for self-sustaining trout.

“It’s a big deal,” said Steve Karr, chairman of Putah Creek Trout, a nonprofit that has worked for years to protect and research the creek’s fishery. “We’re happy because we can catch more fish. But we’re also happy because this could also have some very positive economic advantages for the community in the area.”

The recognition was approved at the commission’s meeting on Dec. 3 in Van Nuys after more than six years of research and monitoring of the fishery in Putah Creek. The research was necessary to ensure the population of coastal rainbow trout is truly self-sustaining.

Putah Creek thus becomes the only designated “wild trout” stream in the California Department of Fish and Wildlife Bay-Delta region, which includes 13 counties in the Bay Area and Sacramento metro area.

The designation includes Lake Solano and 4.5 miles of creek stretching upstream to Monticello Dam at Lake Berryessa. It also requires the department to prepare a management plan for the trout within two years.

The commission also named Putah Creek a “Trophy Trout Water,” meaning its fish often exceed 18 inches long and are numerous enough to be catchable by anglers on a regular basis.

That’s why Karr predicts there will be economic benefit: Thousands of anglers from two huge metropolitan areas will be drawn by the opportunity to catch monster rainbow trout. A bonus is that Putah Creek already offers many other public amenities, including fishing access sites, campgrounds, picnic areas and hiking trails nearby.

“We have caught fish that are 30 inches long. They are just huge – larger than some salmon,” Karr said. “Those fish are caught all year round in that size range.”

One reason the fish are so large, is that, ironically, they benefit from cold water flowing from the base of Monticello Dam. The creek itself, and its streamside habitat, also produce lots of natural fish food.

“Putah has both a really good catch rate and it has large fish, which is kind of rare in California,” said Roger Bloom, inland fisheries program manager at the Department of Fish and Wildlife. “It’s got good water quality, good temperature. It often produces very large fish because of those conditions.”

For decades, the Department of Fish and Wildlife stocked hatchery-raised rainbow trout in the creek. But in 2008, the Center for Biological Diversity filed a lawsuit to stop the planting statewide, largely to protect native amphibians in the Sierra Nevada, where rainbow trout are not native.

A settlement eliminated fish stocking in many waters of the state, and led to an unexpected benefit for Putah Creek. At first, fish abundance declined after stocking stopped, because anglers were still allowed to take home as many as five trout a day. But in 2010, the Fish and Game Commission changed the rules to allow only catch-and-release fishing in Putah Creek, which is still the case.

As a result, the trout grew larger and began to breed into a self-sustaining population.

Karr confessed that he and other anglers initially weren’t pleased when trout stocking stopped in the creek. But in hindsight, he said, it was a good thing.

“Since then, the fishery is on a tremendous rebound in terms of its quality,” he said.

The creek also benefited from a number of restoration projects over the past 20 years to improve habitat and water flow. In 2000, nonprofit groups signed an agreement with the Solano County Water Agency requiring more water flow – and improved timing of those flows – to benefit fish. The agency operates Monticello Dam and the dam at Lake Solano, known as the Putah Diversion Dam.

The improved flows provided enough water for trout to thrive year-round in the creek. Certain minimum flows in some months also helped lure fall-run Chinook salmon back to the creek, although in small numbers.

Historically, Putah Creek was among hundreds in the Sacramento Valley that hosted large salmon runs. It is a tributary of the Sacramento River and the Sacramento-San Joaquin Delta, which salmon traverse on their upstream run from the Pacific Ocean.

For about a century, the creek’s only connection to the Sacramento River is an agricultural drainage ditch that empties into the Sacramento Deep Water Ship Channel. Even so, with enough flow in the creek at the right times, salmon can find their way upstream.

They’ve done so this year in record numbers. There are about 100 fall-run Chinook salmon spawning in the creek this year, said Steve Marovich, the Putah Creek streamkeeper, a position funded by the agreement with the Solano County Water Agency. That compares to one or two dozen salmon in recent years.

“It’s shaping up to be a record year, at least in modern times,” Marovich said. “It’s enough that we’re hopeful we’ll get a proportion of these (salmon) returning to spawn again. That’s really the ultimate goal. Because the ones that spawn in natural creeks seem to survive better in the wild.”

The salmon live exclusively in lower reaches of the creek, below Lake Solano, because they cannot surmount the Putah Diversion Dam.

A lingering issue, Karr said, is to find out just how native the rainbow trout in Putah Creek really are. Although they are officially classified as coastal rainbow trout, a native species, it is possible – after decades of artificial trout planting – that they are a mix of related species. This may include a genetic connection with Central Valley steelhead, a large trout relative that migrates to the ocean, like salmon.

Many steelhead runs became landlocked with the construction of major dams, and that may help explain the very large trout in Putah Creek.

“That is the question we haven’t got answered or even addressed at this point,” Karr said. “But they are definitely wild, they are reproducing, and they are beautiful fish. They have hues of red and green and gold – especially in the larger fish – that is just outstanding.”

Call The Bee’s Matt Weiser at (916) 321-1264. Follow him on Twitter @matt_weiser.

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