Fish survival in Calder Reservoir better than expected

VERNAL — Biologists with the Utah Division of Wildlife Resources found live fish in Calder Reservoir recently.

"The recent nettings in Calder Reservoir found more fish than many anglers predicted," says Ed Johnson, DWR regional aquatic biologist. "This spring, we received quite a bit of feedback from anglers who felt all of the fish in the reservoir died during the winter.

"I'm happy to say Calder has a healthy population of fish."

Michele Swasey (left) and Nikki Merrell show two of the rainbow trout biologists caught during a recent survey at Calder Reservoir.

Photo by Ron Stewart

Calder Reservoir is 35 miles northeast of Vernal.

Finding fish

Johnson says when he and other biologists walked the shorelines of lakes on Diamond Mountain right after the ice melted this spring, dead fish lined the banks, especially at Calder and Crouse reservoirs.

"I was given some hope for Calder, however, as I heard a splash in the water while I was walking the shoreline. Another biologist also saw several rings in the water that he felt must have been made by fish.

"As we waited for the water to warm up so we could do netting surveys to check for survival, we were given more hope; several anglers, including some of our own biologists, reported catching fish or seeing fish jump.

"Although our surveys did confirm a complete winterkill in Crouse Reservoir, at Calder we caught more than one rainbow per hour in our nets. That documented much greater survival than we originally thought."

Losing fish helps the fishery

Calder Reservoir is now under a new management regime. That's one of the reasons anglers gave it so much attention this spring.

"Last year we changed Calder to a 'trophy' management scenario," says Roger Schneidervin, UDWR regional aquatic manager. "Our goal is to use the natural productivity of the reservoir to raise larger fish. That will provide an exciting alternative to Matt Warner and Crouse reservoirs, which are managed for fast fishing and higher catch rates."

Schneidervin says the trophy management strategy comes with tradeoffs. "Some sacrifices are required to produce the big fish anglers get excited about," he says. "The reservoir must be managed with much lower fish densities so the remaining trout have plenty of food and space to grow.

"We changed the bag limit to one trout greater than 22 inches in length and reduced the number of trout we stock in the reservoir. When last spring's surveys showed nearly three trout per hour in the nets, we cut the 2007 stocking rate even more. There were actually too many fish in Calder for the lower bag limit to have its maximum effect.

"Although the hard winter temporarily took away the fishing opportunity at Crouse, nature actually helped us at Calder by reducing trout densities to just about where we want them to be," Schneidervin says. "This is supported by the fact that the trout netted in Calder averaged four inches longer than those collected in Matt Warner. Both of these waters were stocked at the same time last year with fish that were identical in size."

For more information, call the DWR's Northeastern Region office at (435) 781-9453.