On Nov. 25, biologists with the Division of Wildlife Resources released a northern river otter into the Provo River between Jordanelle and Deer Creek reservoirs. (This stretch of the river is commonly referred to as the “middle Provo.”)
The otter, a young adult female, is the first of as many as 10 to 15 otters the DWR hopes to place into the middle Provo River in the next few months. The otter released on Nov. 25 was trapped by DWR biologists on the Green River in northeastern Utah.
Releasing river otters into the middle Provo will provide Utah with another river otter population. It will also provide biologists with valuable information about the habits of river otters in the state.
“Releasing this otter marks the beginning of a three-year study to learn more about otters in Utah,” says Justin Dolling, game mammals coordinator for the DWR.
The day before the otter was released, a veterinarian at Brigham Young University placed a small transmitter in the otter’s abdomen, just under its skin. The transmitter will allow Casey Day to track the otter. Day is a graduate student at BYU.
Transmitters will also be placed in other otters that are released into the river.
“The types of food otters eat, the distances they travel and how successful they are at reproducing are among the things Day will learn,” Dolling says. “The information we gain from his study will guide us in other river otter reintroductions we do in the future.”
UWIN provides funding
Utah Wildlife in Need (UWIN)—a new charitable foundation in Utah—is providing all of the funding for the project.
So far, the foundation has raised $66,000 for the project. That’s half of what’s needed to see the project through to the end.
“If you want to help otters in Utah, this project gives you the perfect chance,” says Bob Hasenyager, UWIN director. “The ALSAM Foundation has provided $66,000 to get the otter project up and going. Now we need other folks to step up and provide the funding needed to see the project through to the end.”
You can learn more about UWIN—and make a donation to the otter project—at http://www.uwin.org/.
Otters and trout
DWR biologists have heard from anglers who are concerned about the effect river otters will have on trout in the middle Provo River.
“Crayfish [also called crawdads] are an otter’s favorite food,” Dolling says. “But if they can’t find crayfish, they’ll turn to other sources, including frogs and fish. An adult otter eats about two to three pounds of food per day.”
Dolling says the middle Provo River has plenty of crayfish. But if the otters have any difficulty finding crayfish in the river, there are plenty of fish to eat. “Otters usually target slower-moving fish, such as sculpin, whitefish, carp and suckers,” he says. “Most of the fish they eat are between five and seven inches long.”
Dolling says the river otters will also eat trout. And that may not be a bad thing.
“This stretch of the river has an abundant trout population that’s dominated by brown trout,” says Roger Wilson, sport fish coordinator for the DWR. “Because there are so many fish in the river, the fish are having to compete with each other for food and space. The competition they’re having is reducing their growth rate and affecting their overall condition.
“Letting otters take some fish could actually improve fishing in the river,” Wilson says. “If otters take some fish, the fish that remain should grow to a larger size.”
Walt Donaldson, Aquatic Section chief for the DWR, says the middle Provo River is a blue ribbon fishery that’s known to anglers across the country. “We reintroduced otters into the Green River in 1989, and they’ve haven’t caused the fish in the river any problems,” he says. “After otters are placed in the Provo River, we’ll keep monitoring the fish population in the river. If we find the otters are causing the fish problems, we can take management actions to make sure fishing in the river doesn’t suffer.”
Those actions include stocking trout in the river and capturing and removing some of the otters.
Not only should the otters not cause problems for fish in the river, they might also add to the enjoyment anglers find while fishing.
“Many anglers who fish the Green River have enjoyed seeing the otters,” Donaldson says. “They say it’s a treat to watch a family of otters play while they’re fishing.”
River otters were never abundant in Utah. But they were found in various parts of the state. Some of the biggest populations were in northern Utah.
River otters were doing fine until Utah was settled. Then over trapping started to take a toll. In 1899, the Utah Legislature closed the state to otter trapping.
Otters faced another challenge, though: the degradation of vegetation along steam banks, and agricultural and urban encroachment. Each of these factors affected water levels and water quality in the state. And that, in turn, that affected the otters’ food supply.
As their habitat and food supply declined, the number of otters declined too.
Bringing otters back
Management practices during the 1900s improved conditions along some of the state’s steam banks. That, in turn, improved water quality. By the 1980s, it was time to increase the number of river otters in Utah.
The DWR started expanding river otter populations in 1989 when biologists released nine otters from Nevada and Alaska into the Green River in northeastern Utah.
The DWR followed the 1989 release with several more otters releases in the area.
In 2005, Utah’s river otter population expanded more when three otters trapped by the DWR in ortheastern Utah were released into the Escalante River in southwestern Utah.
That release was also followed by several other releases in the river.
More information about river otters and their future in Utah is available in the state’s River Otter Management Plan. The free plan is available at www.wildlife.utah.gov/pdf/otter_plan.pdf