New Zealand Mud Snails Found in Utah State Fish Hatchery
Utah Division of Wildlife Resources 08.31.12
The Loa State Fish Hatchery is under temporary quarantine, the Division of Wildlife Resources announced Aug. 31.
The quarantine comes after aquatic invasive species (AIS) biologists with the DWR found tiny New Zealand mud snails at the hatchery. They found the snails during a routine inspection of the hatchery in mid August.
“We’re not sure how snails found their way into the hatchery again,” says Terry Howick, fish culture supervisor for the DWR. “The number of snails is fairly small, but they’re widespread throughout the hatchery.”
This is the second time mud snails have been found in the Loa hatchery. The first time was in 2007.
As it did in 2007, Howick says the DWR has placed the hatchery under quarantine. And it will stay under quarantine until the mud snails are removed.
Howick says it will take about four to five months to disinfect the hatchery.
“We’ve found mud snails in the hatchery two times in the last five years,” Howick says. “Even though it’s rare for a fish to pass a live mud snail into the water, we’re not going to take any chances. From now on, fish from Loa will be placed only in waters that already have New Zealand mud snails in them.”
The Loa hatchery is in the town of Loa, about 40 miles southeast of Richfield. Most of the trout the hatchery raises are typically placed in waters in southern Utah.
Howick says stocking schedules among the Loa hatchery and the DWR’s other hatcheries will be adjusted. Waters that don’t have mud snails in them, but used to receive fish from Loa, will now receive fish from other hatcheries.
“In return,” he says, “fish from the Loa hatchery will be placed only in waters that have mud snails in them, including waters that are currently being stocked by other hatcheries.”
Preventing their spread
New Zealand mud snails are just one of several AIS that have made their way into Utah.
All of the New Zealand mud snails that are found in Utah are female and reproduce asexually. Because they’re asexual, only one snail is required to establish a new colony. One snail can produce hundreds of young every year. And the snails are very effective at colonizing new waters.
There’s good news, though: There are several things you can do to avoid bringing AIS into Utah from outside the state and to avoid transporting it from one body of water in Utah to another:
- To disinfect your equipment, scrub it with a brush and rinse it with water from the stream to remove the mud snails. Make sure you remove the laces from your boots so you can clean under them. After you’ve scrubbed your boots, repeatedly spray your wading boots and equipment with Formula 409 All-Purpose Cleaner, keeping it damp with the 409 disinfectant for 10 minutes. (Formula 409 All-Purpose Cleaner contains an ammonium compound that kills New Zealand mud snails).
- After you’ve sprayed your equipment with Formula 409 All-Purpose Cleaner, let it dry in the sun for an hour before re-using it. This process will kill any snails you can’t see.
- If you’re fishing on a river or stream, disinfect your waders and gear before moving to a different stretch of the same river to fish.
New Zealand mud snails
AIS are destructive plants and animals. In other states, they’ve already ruined fishing and affected boating and recreational activities in waters they’ve infested.
New Zealand mud snails arrived in North America from New Zealand in 1987 when they were discovered in Idaho.
Biologists believe they traveled to Idaho in damp felt on the soles of an angler’s wading boots. That seems to be the primary way they’ve been spread in the West.
Once the snails arrived, their populations exploded, literally covering the bottom of lakes and streams by the millions where they were introduced.
You can learn more about AIS at www.wildlife.utah.gov/dwr/invasive-mussels.html. Specific information about New Zealand mud snails is available at www.wildlife.utah.gov/habitat/ans/nzm.php.
