It was a winter day that seemed like spring. The sky was cloudless. The temperature was balmy. The trout were hungry. The casts were perfect — well, most of them were, anyway. The day was ideal for wading in the river section of half-mile-long Baum Lake, which is located 10 miles northeast of Burney in Shasta County.
But all was not so perfect under the water in this section of the lake near the dam. The rocks were covered with what looked like nonnative New Zealand mudsnails (NZMS) that are found in a growing list of streams, including my home water, Putah Creek, which flows out of Lake Berryessa and past the city of Davis. Baum Lake — elevation 2,976 feet — is a popular fly-fishing destination, mostly because gas-powered motors are not allowed. It can be fished easily from a float tube or a pram with an electric motor and supports wild rainbows, browns, and brook trout, as well as hatchery-raised trout. Its neighboring campgrounds and proximity to designated Wild Trout waters make Baum a favorite destination for fly-fishing club outings. The lake, actually a section of Hat Creek between PG&E Powerhouses 1 and 2, is named for Frank Baum, a hydroelectric pioneer who lived from 1870 to 1932.
Because of its rural location, one doesn’t expect to find the invasive snails. But the rocks in the stream were covered with thousands of tiny black, coneshaped mollusks. A staff member at the Crystal Lake Fish Hatchery near the lake said these were not in fact New Zealand mudsnails, but instead were Ahjumawa pebblesnails, which are native to California and are common in the area’s waters. But to be sure of the identification, the staffer asked that he be sent a photograph of the snail-covered rock.
That conversation with a hatchery staffer showed that identifying the New Zealand mudsnails can be tricky for the average angler and that the California Department of Fish and Wildlife (CDFW) is trying to document exact locations of invasive snails.
According to the CDFW’s Web site, New Zealand mudsnails have been found “in many lakes and river systems, including, but not limited to, the Owens, Klamath, Russian, Lower American, Stanislaus, Merced, San Joaquin and Sacramento rivers and in many of their tributaries. In February 2016, NZMS were discovered in the lower Yuba and lower Feather rivers.”
According to the University of California New Zealand Mudsnail Research and Extension Web site (http://ucanr.edu/sites/uccenzms), New Zealand mudsnails were first found in the United States in Idaho in 1987. They appeared in California in the late 1990s in the Owens River and were discovered in Southern California in Malibu Creek in 2005 and in Piru Creek in the Santa Clara River watershed in 2006. Since their discovery in Malibu Creek, they have spread to several streams in the Santa Monica Mountains.
New Zealand mudsnails are breeding machines. They reproduce in colonies and bear live young. Broods of up to 120 can be produced three times per year in warm climates, and a single female and her offspring are capable of yielding 40 million individuals in a year.
Because of public education campaigns by the CDFW, fly fishers are fairly familiar with the proliferation of New Zealand mudsnails and their impact on a wide range of rivers and streams. New Zealand mudsnails can hitch a ride on fishing gear, water sampling equipment, shoes (in the treads and under the laces), and clothes, as well as on the fur of dogs and the hair of horses.
The UC research site notes: “We know of no way to get rid of them once they invade a river system, other than drastic dewatering or poisoning. Researchers are investigating options for biological control.”
Fly fishers are probably less familiar with other aquatic invasive species, including the extensive list of aquatic invasive plants that are choking off sloughs and marinas, particularly in the Sacramento–San Joaquin Delta. According to the CDFW, the state has 1,100 species, subspecies, and varieties of plants that do not occur naturally in California. According to the California Invasive Plant Council, “Invasive plants reduce habitat for game species. This stress on wildlife reduces fishing resources. Invasive aquatic plants form dense mats that restrict boat access and kill fish by reducing oxygen in the water. Invasive plants can significantly degrade wildlife habitat. Nationally, invasive species [of plants] are the second greatest threat to endangered species, after habitat destruction.”
Invasive aquatic plants have been clogging marinas to such an extent that the plants must be chemically treated to keep water open for boats. Many of these invasive plants were introduced by people emptying aquariums into waterways. “Brazilian waterweed is a major problem in the Delta,” said Peter Moyle, a UC Davis fisheries biologist who has worked on the Delta for many years. “This is a plant used in aquariums that got dumped. So is water hyacinth. We spend millions of dollars per year trying to control them.”
These weeds grow in many Delta sloughs, Moyle added, but the upside for anglers is that they provide good habitat for warm water fish species. “The plants are great for bluegills and bass — that’s why we have such a great fishery for those species in the Delta,” he said. “But the plants are very bad for native fish.”
The warming climate and its resulting increased water temperatures in streams is causing a shift in fish species. “Nonnative species are getting more abundant and natives are on the decline,” Moyle said. “Carp, largemouth bass, bluegills, sunfish, catfish species, and especially bullheads — they are all doing great.”
Other prominent invasives in California’s waters include the quagga and zebra mussels. According to the CDFW, as of 2011, quagga mussels had been found in 39 counties, with concentrations in the San Francisco Bay Area and Los Angeles. They are also now invading the waters in rural areas of Mono and Inyo Counties in the eastern Sierra and coastal Del Norte County, which borders Oregon. One quagga mussel was recently found on a boat trailer at an inspection station at Lake Tahoe, which is free of invasive snails and mussels.
Quaggas and the somewhat similar zebra mussels range from solid light brown to dark brown, depending on their life stages, and are from microscopic to two inches in length. Quaggas were first discovered on January 6, 2007, on the Colorado River in Lake Mead, according to the CDFW, and zebras were first found on January 10, 2008, in San Justo Reservoir in San Benito County, the only area where they currently are known to live in California.
What are the environmental impacts of quagga/zebra mussels? “The mussels are filter feeders that can consume large quantities of the microscopic plants and animals that other species depend on,” says the CDFW. “As a result the ecological balance of an entire water body can be disturbed, displacing native species and sport fish.”
According to the CDFW, adult quagga and zebra mussels can survive out of the water for a week or longer, and are spread by attaching themselves to boats and boat trailers. The CDFW reports that eradication of the mussels is possible if the density is low, but “eradication can be very expensive. Preventing their spread is the best course of action. However, since their larvae are free drifting, preventing their spread downstream from known infestations may not be possible.” The snails have no known predators. Monitoring has shown that some species of ducks and fish eat them, but not in large enough numbers to be an effective control.
The best way to prevent the spread of invasive snails and mussels is to keep all watercraft, including kayaks and inflatables, as well as all fishing gear that comes in contact with water, clean and dry between outings, and boats with bilges need to be clean and dry, too. The CDFW has recommended ways for anglers to prevent invasives from being spread on waders and boots. An excellent brochure on treatment of gear to prevent spread of snails is available at http://www.dfw.state.or.us/conservationstrategy/invasive_species/docs/NZ_Mudsnails_10-page.pdf.
Snails, mussels, and plants are not the only invasives in California’s waters. The CDFW has embarked on an effort to eradicate the northern watersnake, which has been found near Roseville, and it is also targeting the Florida/southern watersnake, which has been found near Folsom. The CDFW is seeking volunteers to help with the snake-trapping project.
“Prevention is the most effective strategy in managing invasive species,” the CDFW says. “However, hundreds of invasive plants and animals have already established in California and are rapidly spreading each year. These invaders are negatively impacting our waters, our native plants and animals — some of them rare, threatened or endangered.”
For more information on the mussels, use the CDFW’s Frequently Asked Questions link at https://www.wildlife. ca.gov/Conservation/ Invasives/Quagga-Mussels. For a map of snail locations, go to https://nrm.dfg.ca.gov/FileHandler. DocumentID=140819&inline. Information on invasive plant species is available from the California Invasive Plant Council at www.cal-ipc.org. For more information on invasives, call the CDFW hotline at (866) 440-9530 or go to www.wildlife.ca.gov/mussels.
Marijuana Water Demands
Fish-and-wildlife officials are documenting the enormous impact of illegal marijuana growing sites on trout, steelhead, and salmon streams. “In California, between 2001 and 2015, more than 8,000 grow sites were detected and eradicated,” states an article written by Jane Hendron, public affairs officer of the CDFW’s Carlsbad office. She noted that most of these eradicated sites were located on federal land. “Grow sites are especially common in the ‘Emerald Triangle’ — an area encompassing Humboldt, Mendocino, and Trinity Counties. They have been found on the Bureau of Land Management’s Beauty Mountain Wilderness Study Area in Riverside County, in Shasta-Trinity National Forest, and in a designated wilderness area of Sequoia National Park.” The impact of these grow sites on rivers is nothing short of staggering. In the article, Hendron quotes Mike Higley, a biologist for the Hoopa tribe, saying: “There were more than 26,000 plants spread among six different patches along a mile of stream. To grow that many plants, they need enough water to fill about 27 Olympic-size swimming pools. And that’s just one site.” Illegal marijuana cultivation requires water — and lots of it. Scientists estimate a single marijuana plant requires up to six gallons of water per day.
Officials working to restore the grow sites find large amounts of trash and toxic chemicals. “While there is no research to quantify how these chemicals are affecting the aquatic environment,” said Darren Mierau, North Coast director for California Trout, “the illegal marijuana cultivation sites are adding to the already serious issue. It’s nearly impossible to track impacts from these illegal sites on native fish populations, but we are currently at 5 to 10 percent of historic population levels.”
Big Bear Lake to Build Hatchery
Responding to a drop in CDFW-raised planter trout, the Big Bear Municipal Water District approved building a fish hatchery. The $3.5 million hatchery will produce 150,000 pounds of rainbow trout per year, according to the district, and also house educational programs and projects devoted to rearing rare and endangered fish and host tours of the facility. “We plan to be making fish within a year,” Mike Stephenson, the district’s lake manager, told the Los Angeles Times. Big Bear is a popular lake and resort area in the San Bernardino Mountains.
Senate Approves Fishing License Reform Bill
California’s State Senate unanimously approved Senate Bill 187, which would change the state’s calendar-based fishing license to one that is valid for a full 12 months from the date of purchase. “This bill would not only improve access to recreational fishing, it will protect California jobs dependent on outdoor tourism,” said Senator Tom Berryhill, R-Twain Harte, who sponsored the bill. “Labor unions, state and local chambers of commerce, anglers, tourism groups, and everyday Californians recognize that California’s antiquated fishing licensing program has proven to be a barrier to participation.” A similar bill failed to reach the Senate floor in 2015. The bill is under review by a State Assembly committee.
Boaters Will Soon Need Safety Card
Some Californians who use boats to fish will be required to have a boating safety card next year. The California Boater Card will be issued by the California State Parks Division of Boating and Waterways (DBW), which will begin issuing the cards on January 1, 2018, but they can be applied for earlier.
The card will show that its holder has successfully taken and passed a state-approved boater safety education examination. The new requirement will begin on January 1, 2018 for all persons 20 years of age and younger who operate a motorized vessel on state waterways. On that date, these boaters will be required to carry a boater card issued by the DBW.
Each year after January 2018, an older age group will be added to those who are required to possess a valid card. By 2025, all persons who operate a motorized vessel on California waters will be required to have one. Once issued, the card remains valid for a boat operator’s lifetime. The California Harbors and Navigation Code Section 678.11(b) contains the following phase-in schedule based on operator age.
Persons 20 years of age or younger: January 1, 2018
Persons 25 years of age or younger: January 1, 2019
Persons 35 years of age or younger: January 1, 2020
Persons 40 years of age or younger: January 1, 2021
Persons 45 years of age or younger: January 1, 2022
Persons 50 years of age or younger: January 1, 2023
Persons 60 years of age or younger: January 1, 2024
All persons regardless of age: January 1, 2025
The DBW’s Boater Card Technical Advisory Group anticipates that the cost of the card will be no more than $10. For more information on the card, go to see http://dbw.parks.ca.gov/?page_id=29373.
