Category Archives: Invasive Species

Nutria Discovered in San Joaquin Valley; CDFW Seeks to Prevent Further Spread and Infestation

The California Department of Fish and Wildlife (CDFW) has become aware of a population of invasive nutria (Myocastor coypus) reproducing within the San Joaquin Valley. Given the severity of potential impacts and the impacts realized in other infested states, CDFW believes early intervention actions could be successful in eradicating nutria from the area and is asking the public’s help in looking for and reporting nutria sightings in order to determine the extent of the infestation.

To date, nutria have been found in wetlands, rivers, canals and other freshwater habitat in Merced, Fresno and Stanislaus counties. If allowed to establish, nutria will severely impact California’s resources, causing the loss of wetlands, severe soil erosion, damage to agricultural crops and levees and reduced stability of banks, dikes and roadbeds, as they have done in Louisiana, Chesapeake Bay and the Pacific Northwest. Nutria also degrade water quality and contaminate drinking supplies with parasites and diseases transmissible to humans, livestock and pets.

Native to South America, nutria are large, semi-aquatic rodents that reach up to 2.5 feet in body length, 12-inch tail length and 20 pounds in weight. Nutria strongly resemble native beaver and muskrat, but are distinguished by their round, sparsely haired tails and white whiskers (see CDFW’s Nutria Identification Guide). Both nutria and muskrat often have white muzzles, but muskrats have dark whiskers, nearly triangular (laterally compressed) tails and reach a maximum size of five pounds. Beavers have wide, flattened tails and dark whiskers and reach up to 60 pounds.

Female nutria are reproductive by six months of age, breed year-round, and can produce three litters in 13 months. Within approximately one year of reaching reproductive maturity, one female nutria can result in more than 200 offspring, which can disperse as far as 50 miles.

Nutria are destructive, wasteful feeders that destroy up to 10 times the vegetation they consume. Signs of presence typically include cut, emergent vegetation (e.g. cattails and bulrushes), with only the base portions eaten and the stems left floating. Nutria construct burrows with entrances typically below the water line, though changing water levels may reveal openings. Similar to other aquatic mammals, nutria often create runs, or paths in and out of the water or between aquatic sites. Nutria tracks have four visible front toes and, on their hind feet, webbing between four of five toes. Tracks are often accompanied by narrow tail drags.

Since March 30, 2017, more than 20 nutria, including males, pregnant females and juveniles, have been documented within private wetlands near Gustine, duck clubs, the Merced River near Cressey, adjacent to the San Joaquin River near Grayson, south of Dos Palos, the San Luis National Wildlife Refuge, and Salt Slough  on the San Joaquin River. The full extent of the infestation is not yet known.

A multiagency Nutria Response Team, which includes representatives from CDFW, the California Departments of Food and Agriculture, Parks and Recreation, and Water Resources, the U.S. Department of Agriculture, the U.S. Fish and Wildlife Service and local county agricultural commissioner offices, has convened with the goal of eradicating nutria from the state. The response team is currently preparing an eradication plan, the first stage of which is determining the full extent of the infestation. Assistance from local landowners and the public throughout the Central Valley, Sacramento-San Joaquin Delta and beyond is critical to successfully delineating the population.

Suspected observations or potential signs of nutria should be photographed and immediately reported to CDFW’s Invasive Species Program online, by e-mail to invasives@wildlife.ca.gov, or by phone at (866) 440-9530. Observations on state or federal lands should be immediately reported to local agency staff at that land. CDFW has a nutria webpage and a downloadable PDF with photos and detailed descriptions of these rodents, their preferred habitat and the environmental threats they present.

Media Contacts:
Peter Tira, CDFW Communications, (916) 322-8908
Martha Volkoff, CDFW Invasive Species Program, (916) 651-8658

 

Nutria photo courtesy of Joyce Gross, UC Berkeley.

Invasive New Zealand Mudsnails Found in Carmel River – Residents and Visitors Urged to Help Prevent Further Spread

The California Department of Fish and Wildlife (CDFW) has confirmed the presence of New Zealand mudsnails in Monterey County’s Carmel River.

The highly invasive, nonnative snails have been detected by the Monterey Peninsula Water Management District at multiple locations in the lower river, including near the Highway 1 crossing, the Valley Greens Drive bridge, and Mid Valley nearly 8 miles upstream from the mouth of the river at the Carmel River State Beach along the Pacific Ocean. No mudsnails were found in locations upriver from Red Rock to the base of Los Padres Dam.

CDFW urges visitors and those in the community to “clean, drain and dry” all recreational and fishing gear in order to prevent the further spread of the snails. It is illegal to import, possess or transport the mudsnails without a permit and offenders can be cited.

Despite their small size, New Zealand mudsnails are a problematic aquatic species. Only 4 to 6 millimeters long on average, dense populations of New Zealand mudsnails can displace and out-compete native species, sometimes by consuming up to half the food resources in a waterway. The snails have been linked to reduced populations of aquatic insects, including mayflies, stoneflies, caddisflies, chironomids and other insect groups upon which trout and steelhead populations depend.

The Carmel River is home to a fragile population of threatened steelhead listed under the federal Endangered Species Act. Boaters, anglers and others who may visit the Carmel River, within or outside infested areas, are asked to decontaminate their equipment and follow the “clean, drain and dry” best practices with all equipment used in the river:

  • If you wade, freeze waders and other gear overnight (at least six hours).
  • After leaving the water, inspect waders, boots, float tubes, paddleboards, kayaks or any gear used in the water. Remove any visible snails with a stiff brush and follow with rinsing. If possible, freeze or completely dry out any wet gear.
  • Never transport live fish or other aquatic plants or animals from one body of water to another.

An informational flier on the “clean, drain and dry” directive is available for download at https://nrm.dfg.ca.gov/FileHandler.ashx?DocumentID=3866&inline.

To date, low numbers of New Zealand mudsnails have been identified in two other locations in Monterey County (the Salinas and San Antonio rivers).

In the coming weeks, CDFW will launch a public outreach and education effort, including distribution of information cards, brochures and signage posted at the Carmel River State Beach and at other access points along the Carmel River.

For more information on the New Zealand mudsnail, please visit CDFW’s Invasive Species website at www.wildlife.ca.gov/Conservation/Invasives/Species/NZmudsnail.

The current distribution of mudsnails in California and throughout the United States can be viewed at the U.S. Geological Survey’s interactive map, https://nas.er.usgs.gov/viewer/omap.aspx?SpeciesID=1008.

Media Contact:
Peter Tira, CDFW Communications, (916) 322-8908

Boaters Can Help Fight Spread of Invasive Mussels Over Labor Day Weekend

California agencies combatting the spread of invasive quagga and zebra mussels remind boaters to remain cautious over Labor Day weekend.

Quagga and zebra mussels are invasive freshwater mussels native to Eurasia. They multiply quickly, encrust watercraft and infrastructure, alter water quality and the aquatic food web and ultimately impact native and sport fish communities. These mussels spread from one body of water to another by attaching to watercraft, equipment and nearly anything that has been in an infested waterbody.

Microscopic juveniles, invisible to the naked eye, are spread from infested waterbodies in water entrapped in boat engines, bilges, live-wells and buckets. Quagga mussels have infested 33 waterways in Southern California and zebra mussels have infested two waterways in San Benito County.

To prevent the spread of these mussels and other aquatic invasive species, people launching vessels at any body of water are subject to watercraft inspections and are strongly encouraged to clean, drain and dry their motorized and non-motorized boats, including personal watercraft, and any equipment that contacts the water before and after recreating.

“It has been a great year to enjoy our lakes and rivers, and boaters are instrumental in protecting California’s waters,” said California Department of Fish and Wildlife (CDFW) Habitat Conservation Planning Branch Chief Rick Macedo. “As the season winds down, boaters should continue to Clean, Drain, and Dry their watercraft after every outing to protect these cherished destinations for the future.”

Take the following steps both before traveling to and before leaving a waterbody to prevent spreading invasive mussels, improve your inspection experience and safeguard California waterways:

  • CLEAN — inspect exposed surfaces and remove all plants and organisms,
  • DRAIN — all water, including water contained in lower outboard units, live-wells and bait buckets, and
  • DRY — allow the watercraft to thoroughly dry between launches. Watercraft should be kept dry for at least five days in warm weather and up to 30 days in cool weather.

CDFW has developed a brief video demonstrating the ease of implementing the clean, drain and dry prevention method, which can be viewed at www.youtube.com/watch?v=GaeAIPLoK-k. In addition, a detailed guide to cleaning vessels of invasive mussels is available on the CDFW’s webpage at https://nrm.dfg.ca.gov/FileHandler.ashx?DocumentID=4957&inline. Additional information is available on the Division of Boating and Waterways (DBW) website at http://dbw.parks.ca.gov/?page_id=28996.

Travelers are also advised to be prepared for inspections at California Department of Food and Agriculture (CDFA) Border Protection Stations. Over the past nine years, more than 1 million watercraft entering California have been inspected at the Border Protection Stations. Inspections, which can also be conducted by CDFW and California State Parks, include a check of boats and personal watercraft, as well as trailers and all onboard items. Contaminated vessels and equipment are subject to decontamination, rejection, quarantine or impoundment.

Quagga and zebra mussels can attach to and damage virtually any submerged surface. They can:

  • Ruin a boat engine by blocking the cooling system and causing it to overheat
  • Jam a boat’s steering equipment, putting occupants and others at risk
  • Require frequent scraping and repainting of boat hulls
  • Colonize all underwater substrates such as boat ramps, docks, lines and other underwater surfaces, causing them to require constant cleaning
  • Impose large expenses to owners

A multi-agency effort that includes CDFW, DBW, CDFA and the California Department of Water Resources has been leading an outreach campaign to alert the public to the quagga and zebra mussel threats. A toll-free hotline, (866) 440-9530, is available for those seeking information on quagga or zebra mussels.

Media Contacts:
Adeline Yee, California State Parks Division of Boating and Waterways, (916) 651-8725
Kyle Orr, California Department of Fish and Wildlife, (916) 322-8958
Doug Carlson, California Department of Water Resources, (916) 653-5114
Steve Lyle, California Department of Food and Agriculture, (916) 654-0462

CDFW’s Invasive Species Program Announces Youth Art Contest Winners

The winners of the “Don’t Let it Loose!” Youth Art Contest have been announced by the California Department of Fish and Wildlife (CDFW) Invasive Species Program.

As part of the California Invasive Species Action Week, 126 youths from across California submitted their original artwork. Participants were asked to send artwork depicting invasive species that might be released by pet/aquarium owners, how their release impacts our natural resources, or what one could do with unwanted pets/plants instead of releasing them. The top three posters from each grade division were selected by members of the CDFW’s Invasive Species Program and the poster which best exemplified the contest theme was selected as the CDFW Invasive Species Program Choice Award.

Noah Petersen (5th Grade), of Fresno (Fort Washington Elementary School), was named the winner of the Invasive Species Program Choice Award. Peterson created a poster outlining multiple ways to be a responsible pet owner and avoid letting invasive species loose.

The top winners of the 2017 Invasive Species Action Week Youth Art Contest divisions were:

Grades 2-4

First Place: Jennifer Kang, 7, Mountain View, Springer Elementary School

Second Place: CJ Andelman, 10, Santa Barbara, Homeschool

Third Place: Lucia Wilkinson, 7, Carmichael, Cowan Fundamental Elementary

Grades 5-8

First Place: Aaliyah Zamorano (6th Grade), Roseville, Excelsior Elementary School

Second Place: Jaya Wollenberger (6th Grade), Roseville, Excelsior Elementary School

Third Place: Maria Ramirez, 14, Santa Cruz, Mission Hill Elementary School

Grades 9-12

First Place: Esmé Kim Ison, 17, Santa Monica, Santa Monica High School

Second Place: Summer Knight, 15, Roseville, Woodcreek High School

Third Place: Alexa Aitchison, 16, Chula Vista, Eastlake High School

CDFW congratulates all the participants for their excellent work, and thanks the teachers, nature centers, volunteer organizations and parents who encouraged, educated and assisted the students.

For more information or to obtain artwork images, please contact the Invasive Species Program at invasives@wildlife.ca.gov.

Media Contacts:
Rachael Klopfenstein, CDFW Invasive Species Program, (916) 651-3122
Kyle Orr, CDFW Communications, (916) 322-8958

 

Help Kick Off California Invasive Species Action Week by Volunteering

The fourth annual California Invasive Species Action Week will run from Saturday, June 3 through Sunday, June 11. Sponsored by the California Department of Fish and Wildlife (CDFW), Invasive Species Action Week is a statewide event that provides the public with opportunities to learn about and take action against non-native plants and animals that harm our environment and the native species that live here.

Federal and state agencies and numerous organizations across the state have teamed up to host more than 40 individual Action Week events this year. Examples of upcoming public volunteer opportunities include:

  • Sacramento County: CDFW’s Marine Invasive Species Program will be hosting interactive displays, screening of educational videos and a chance to see live and preserved invaders from June 5-9 at the Nimbus Hatchery Visitor Center. This family-friendly opportunity will have activities for all ages and picnic facilities are on site.
  • Mendocino County: Mussel Dogs (a consulting and inspection service) will host a public demonstration of their Quagga and zebra mussel detection dogs’ work on the banks of Lake Mendocino on Saturday, June 3, from 7 a.m. to 3 p.m.
  • Sonoma County: California State Parks and Stewards of the Coast and Redwoods will host an invasive plant removal volunteer day in the Armstrong Redwoods State Natural Preserve on Wednesday, June 7, from 9 a.m. to noon.
  • Los Angeles County: The Mountain Restoration Trust needs volunteers to help trap and remove invasive red swamp crayfish from the Malibu Creek Watershed on Saturday, June 10 from 9 to 11 a.m.

Many other counties will also have volunteer opportunities this week. To view the full schedule of events and map, please visit www.wildlife.ca.gov/CISAW.

Don’t forget – stopping the spread of invasive species does not have to wait for the Action Week! Citizens can also contribute to a healthy environment by taking small, everyday actions – like selecting native plants for landscaping, cleaning your outdoor and aquatic gear after use, being responsible pet and aquaria owners, and reporting invasive species findings.

Another opportunity to monitor for invasive species during and beyond the Action Week is through California Nerodia Watch, the CDFW’s citizen-science monitoring project for invasive (and restricted) Nerodia watersnakes. Currently, Nerodia watersnake populations are established in Roseville, Folsom and Harbor City, with several sightings reported in the Sacramento-San Joaquin Delta. Nerodia are notorious predators of fish and amphibians, and if their range expands, they will pose a serious threat to nearby endangered fish and wildlife. Members of the public are encouraged to help CDFW biologists to monitor and prevent the spread of existing populations! Visit the CDFW invasive species profiles at www.wildlife.ca.gov/conservation/invasives/species to learn more and report observations through the iNaturalist project webpage (www.inaturalist.org/projects/california-nerodia-watch) or by downloading the iNaturalist smartphone app.

For questions or more information about Action Week or California Nerodia Watch, please contact invasives@wildlife.ca.gov.

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Media Contacts:
Rachael Klopfenstein, CDFW Invasive Species Program, (916) 651-3122
Kirsten Macintyre, CDFW Communications, (916) 322-8988