WESPEN Online Order Form print this page
US Fish & Wildlife Service FieldNotes

ARCATA FWO: Biologists Discover Invasive Species While Surveying for an Endangered One

 

Region 8, September 9, 2008
U.S. Fish and Wildlife Service Biologist Greg Goldsmith in Big Lagoon, Humboldt County, Calif. Goldsmith and his colleagues discovered the presence of the invasive New Zealand Mudsnails during a survey for the listed tidewater goby. (photo: Tyson Ritter/The Eureka Reporter)
U.S. Fish and Wildlife Service Biologist Greg Goldsmith in Big Lagoon, Humboldt County, Calif. Goldsmith and his colleagues discovered the presence of the invasive New Zealand Mudsnails during a survey for the listed tidewater goby. (photo: Tyson Ritter/The Eureka Reporter) - Photo Credit: n/a
Believed to be the first positive discovery of the New Zealand Mudsnail in the North Coast Region of California, The mudsnails can be as small as a grain of sand and reach lengths of up to an 1/8 of an inch. (photo: Tyson Ritter/The Eureka Reporter)
Believed to be the first positive discovery of the New Zealand Mudsnail in the North Coast Region of California, The mudsnails can be as small as a grain of sand and reach lengths of up to an 1/8 of an inch. (photo: Tyson Ritter/The Eureka Reporter) - Photo Credit: n/a
Goldsmith and colleagues collected samples of the snail to be positively identified. The Arcata FWO is working with California Department of Fish and Game to spread the word about preventing the snails from inhabiting other nearby waters. (photo: Tyson Ritter/The Eureka Reporter)
Goldsmith and colleagues collected samples of the snail to be positively identified. The Arcata FWO is working with California Department of Fish and Game to spread the word about preventing the snails from inhabiting other nearby waters. (photo: Tyson Ritter/The Eureka Reporter) - Photo Credit: n/a

By Matt Baun, Arcata FWO

Earlier this month, a team of biologists from the Arcata Fish and Wildlife Office discovered thousands of invasive New Zealand Mudsnails (NZMS) in Big Lagoon, a popular Humboldt County recreational destination that lies north of the coastal town of Trinidad in Northern California.

 

“Knowing that the New Zealand Mudsnails are very small, we decided to collect a sample and have them positively identified,” said Greg Goldsmith, one of the biologists who made the discovery.

 

Goldsmith and colleagues Tony Scheiff and Katrina Wright captured the snails in their seine nets while they were surveying for the presence of the tidewater goby in the shallows of the Lagoon.

 

On September 18, the FWS received preliminary confirmation that the species is the NZMS.  In total, tens of thousands of the tiny snails were observed since they were discovered on September 9.

 

Goldsmith noted that he had never seen snails approaching the density that he and his crew encountered in Big Lagoon, adding that all of the snails were uniform in size.  

 

Mudsnails were first discovered in the U.S. in Idaho’s Snake River in the 1980s and has rapidly spread throughout the West.  They have been discovered in waters throughout California.  The discovery in Big Lagoon is believed to be the first confirmed occurrence in the North Coast region. 

 

The mudsnail should not be confused with invasive mussels, such as quagga and zebra mussels, which are often considerably more detrimental to ecosystems and underwater infrastructure. Still, mudsnails are a threat to native waters and they compete with native invertebrates for food and habitat, which may have serious consequences for fish populations, vegetation, and other native biota. 

 

The mudsnails are brown or black in color and can be as small as a grain of sand and reach lengths of up to an 1/8 of an inch.  Mudsnails can tolerate a wide range of habitats, including brackish water, and are found living in high densities (often over 400,000 snails/sq meter) on many different substrates such as rock, gravel, sand, and mud). They reproduce asexually and in vast numbers. 

 

There are no effective eradication procedures once these species are established in water bodies.  It is critical that the further spread of the NZMS is prevented. The NZMS is primarily spread into new waters by people. Anglers, boaters, researchers and others who transport potentially contaminated gear and equipment can easily move these species to new locations.  Public education and preventive measures are the best means for controlling the spread of these invasive species. 

 

What you can do to prevent the spread of New Zealand Mudsnails:

·        Have extra waders and boots for use in infested waters only. Store them separately.

·        After leaving the water inspect waders, boots, float tubes, boats and trailers, and any gear used in the water.

·        Remove visible snails with a stiff brush and follow with a rinsing.

·        If possible, freeze or completely dry out wet gear before reuse.

·        Never transport live fish or other aquatic animals or plants from one body of water to another.

For more information on New Zealand mudsnails in California, visit the California Department of Fish and Game Web site at www.dfg.ca.gov/invasives/mudsnail.  Additional information can be found at: http://www.esg.montana.edu/aim/mollusca/nzms/.

Contact Info: Matt Baun, 530-842-5763, matt_baun@fws.gov