Oroville lifts mussel inspections; will others follow suit:?

The California Department of Water Resources decided unexpectedly to lift golden mussel restrictions on Lake Oroville. According to a press release, as of April 29, "Watercraft inspections, decontamination services and seal checking at Oroville facilities are no longer required." Which sparked the inevitable question: Will other area reservoirs follow suit? Short answer? Don't get your hopes up. Golden mussels first became a real problem in California waters in November 2024. The invasive species was discovered at the Port of Stockton and likely came from an overseas ship illegally dumping ballast water. The mussels, which can lay up to a million eggs at one time, are truly harmful to water conveyance infrastructure and just about anything else they attach to. And, because they are filter feeders that eat the same plankton as baitfish, they can out-compete those species, which could collapse entire food chains. They're bad news, and they've already become a problem in the delta southward (all the way to, believe it or not, San Diego, according to a regularly updated golden mussel map on the website for California Department of Fish and Wildlife). Because their appearance was relatively sudden and unexpected, the various water agencies overseeing our region's reservoirs each had to make quick decisions of how to best mitigate the risk for their respective lakes. Some went all in: East Bay Municipal Water District completely banned outside watercraft on lakes like Camanche and Pardee in 2025. Others opted for inspection programs that offered choices like free watercraft quarantining or a fee-based vessel decontamination. Meanwhile, some smaller cash-strapped agencies haven't even gone that far, relying instead on visual inspections of watercraft and an honor system of "clean, drain and dry." This somewhat patchwork approach has been confusing at best and at worst, occasionally outright baffling. Now, a year and a half in, adjustments are being made. While Pardee is still off limits to all outside watercraft, Camanche is now allowing them after a 30-day quarantine. But, those watercraft are allowed only on Camanche; otherwise, they will be subject to another 30-day quarantine. At the same time, other agencies are staying with inspection and decontamination practices established last year. And at still other lakes, that honor system of clean, drain and dry continues, sometimes with a visual inspection, sometimes not. Oroville, with 3.8 million acre-feet of storage, is now the largest of those lakes. After more than a year of vessel inspection practices similar to Folsom and Berryessa, the decision by DWR to fully lift them altogether at Oroville came as a surprise. In its press release, the bureau explained, "During the last year, DWR performed a vulnerability review of Lake Oroville, the Upper Feather River Lakes, the Feather River Fish Hatchery and Oroville-Thermalito Complex infrastructure to golden mussel colonization." Based on a water temperature study from 2017 that determined optimal breeding conditions for golden mussels, it was found that "for golden mussel maturation and reproduction to occur, water temperatures greater than 61.7°F for about 150 days are necessary for successful spawning and the formation of veligers, the larval stage of mussels. For veligers to complete their development and settle into a hard-shell mussel, water temperatures must be nearly 70°F for approximately 70 days." And so it was concluded that while the mussels could survive for a time in the lake's upper 60 feet, seasonal changes in water temperatures, along with regular changes in the lake's water levels, would make long-term establishment of the mussels unlikely. However, that decision is not one that will likely be made anytime soon at other lakes, including Folsom and Berryessa. Drew Ganter, the manager for water resources with the Solano County Water Agency, says Lake Berryessa is "very different from Lake Oroville in many ways, including water quality, seasonal fluctuations and the ecology of the lake." Those factors, he said in an email, make Berryessa a "far more favorable" habitat for golden mussel colonization and as such the "watercraft inspection, banding and decontamination program will remain in place, without modification." The managers of Folsom Lake seem similarly inclined. While the state parks department operates the inspection program there, the ultimate decision of whether it continues belongs to the Bureau of Reclamation, which oversees not only Folsom but other major California reservoirs like Shasta, Trinity and New Melones. In a succinct email reply regarding Folsom Lake specifically, a public information officer with the bureau, Mary Lee Knecht, said, "No changes are planned (for) existing Golden Mussel protocols." It's probably safe to say that statement also includes those other lakes under the bureau's jurisdiction. Protocols and practices will likely continue to be adjusted as more is learned about golden mussels. And, as noted in previous columns here, groups like the Northern California Guide's Association and state agencies like the California Department of Fish and Wildlife will continue working with water agencies to see if cooperative inspection protocols can be created between at least some of them. But, those of us hoping for a return to the smooth sailing we used to have between lakes are likely going to have to treat this like visiting a launch ramp at any lake on a busy weekend: Pack a lunch and your patience. FISHING REPORT Lower American River: This is the peak season for shad, which look like either very small tarpon or very large herring (a species they are actually related to). When a school moves through, the action can be fast, furious and fun. The fish move into the river to spawn and are aggressive toward small, brightly colored jigs if you're spincasting or brightly colored flies and/or "shad darts" if you're using a fly rod. Access the river at several locations, including River Bend Park, Sailor Bar and the Sunrise Recreation Area. Collins Lake This usually dependable lake has been confounding several veteran anglers this year, with one day being wide open and other days challenging even the most experienced. I spoke with Cal Kellogg, a longtime Collins guide and regional fishing guru, and he thinks the trout, which are stocked throughout fall and winter, have keyed in to feeding on plankton rather than the lake's threadfin shad population. To that end, if you'restruggling with traditional presentations, try going small with your lures. Or, see if you can "match" phytoplankton colors: I was there recently and, based on Cal's observations, included a dark green trout trix minnow with my offerings. It was literally the only thing that got bit all day. Folsom Lake That red-hot trout bite seems to be slowing a bit, but at the same time, there are still some beautiful rainbows being caught. Last week, I managed trout of 20, 23 and 24 inches using spoons and small flashers with white hoochies tipped with anchovies anywhere from 30 to 19 feet. Also encouraging: Landlocked king salmon seem to be showing up. On consecutive trips last week we boated kings of 4.5 and 6.5 pounds. One came on a 3" "wonderbread" Speedy Shiner at 36 feet and the other on a brass/red Speedy, also at 36 feet. Fish the river channel off the western shoreline of Granite Bay Recreation Area, or troll along the peninsula up the north fork.