An effort to restore healthy populations of river otters in Northern Utah waterways is officially under way.
Biologists with the Utah Division of Wildlife Resources recently released a female river otter into the middle Provo River, and hope to release as many as 15 over the next few months.
Utah, the second-driest state in the nation, has never been a stronghold of the water-loving river otter. But historical accounts show that otters were once seen with some regularity in waterways throughout the state, with some of the larger populations in Northern Utah.
Explorer and trapper Peter Skene Ogden reported in 1826 that three otters were trapped in Box Elder County, and three years later reported the trapping of six otters from the Bear River and Clarkston Creek in Cache County.
More recently, in the 1970s and 1980s there were documented sightings in the drainages of the Bear, Colorado, Green, Provo, Raft, Sevier and Weber Rivers.
Trapping by settlers became an early threat to the state's river otter populations, prompting the Utah Legislature to outlaw trapping of the furbearing mammals in 1899.
Since then, human development has gradually encroached on more and more otter habitat.
Population growth and agriculture have contributed to the degradation of streamside vegetation and water quality, and increased demand for water has resulted in altered water flows. Those factors have diminished the otters' natural food supply, forcing them to search elsewhere.
Utah's otter reintroduction program got under way in 1989, when officials released the first of 67 otters along the Green River.
The otter recently released into the Provo River was implanted with a transmitter that will allow the gathering of data such as the types of food she is eating, how far she travels, and how successful she is at breeding, said Justin Dolling, game mammals coordinator for the DWR.
"The information we gain from this study will guide us in other river otter reintroductions we do in the future," Dolling said.
Future reintroductions could happen on Top of Utah waterways, as the division's otter management plan calls for reintroduction throughout the otter's historic range. But for now, efforts are mainly focused on the Green and Escalante rivers, and now the Provo River.
The middle Provo is widely known as a blue-ribbon trout fishery, and some anglers have raised concerns about the impact of the carnivorous otter on the river's trout populations.
While they will eat trout, Dolling said crayfish are the otters' preferred food, and otters are more likely to target slower-moving fish like sculpin, whitefish, carp and suckers.
With an abundant trout population dominated by brown trout, fishing on the middle Provo might benefit from the reintroduction of a natural predator, said Roger Wilson, the DWR's sport fish coordinator.
"Letting otters take some fish could actually improve fishing in the river," Wilson said. "If otters take some fish, the fish that remain should grow to a larger size."
Walt Donaldson, aquatic section chief for the DWR, said officials will monitor fish populations to determine the otters' impact, and can stock more trout or remove some otters if needed.
Donaldson said reintroduction efforts on the Green haven't caused any problems for fish species there.
Besides, he said, river otters are fun to watch.
"Many anglers who fish the Green River have enjoyed seeing the otters. They say it's a treat to watch a family of otters play while they're fishing."
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