8/21/2009 10:13:00 PM Native fish restoration effort under way at Upper Verde
Matt Hinshaw/ The Daily Courier Pam Sponholtz, a fish biologist with the U.S. Fish and Wildlife Service, catches fish as she electro-shocks them at Stillman Lake on the Upper Verde River Friday.
Wildlife officials took a major step toward creating a haven for endangered Arizona fish this past week by removing non-native fish from Stillman Lake at the Verde River headwaters.
The U.S. Fish and Wildlife Service, Arizona Game and Fish Department and The Nature Conservancy joined in the two-day effort Thursday and Friday to shock and remove all kinds of fish and turtles in the 20-acre lake about 25 miles northeast of Prescott, before they use a special chemical to kill off any remaining non-native fish the following week.
After more monitoring to make sure all the non-native fish are gone, they will stock the lake with natives such as roundtail chubs (aka Verde trout) and endangered razorback suckers as early as September. They also will stock Sonora and desert suckers. Later, they hope to add the endangered spikedace to the mix.
They dream of seeing these natives produce offspring that can flush over the small natural Stillman Lake dam in flood events and populate the river below.
"That would be a real success," said Pam Sponholtz, a fish biologist with the Fish and Wildlife Service.
Native fish have been unable to successfully reproduce in the lake because non-native fish eat the native fish and out-compete them for habitat. Government officials introduced some of the non-native fish decades ago to meet the demand for sport fishing, before people realized the full potential for harm.
For nearly a decade, researchers have tried to remove non-native fish from the lake by shocking them and netting them, but it just hasn't worked, said Shaula Hedwall, another Fish and Wildlife fish biologist.
So after a public review process, they gained approval to chemically treat the lake with Rotenone. It is a short lived chemical and will not impact wildlife, human populations, or fish downstream from the lake, officials said.
Officials hope to create a native fishery they can manage in the lake.
"It's an extremely high priority for us," Sponholtz said.
"It's at the very top of the list," Hedwall agreed.
The isolated site provides a unique opportunity, added Andy Clark, regional fisheries program manager for Game and Fish. His agency and The Nature Conservancy own the area.
During electro-shocking and netting efforts Thursday and Friday, they located and salvaged only two native fish, both Sonora suckers. They will release them downstream.
Researchers and volunteers also found five native Sonoran mud turtles, which will spend some time at the home of Kim Schonek until the chemicals wear off at the lake in a week or so. Schonek is the Verde Rivers Project manager for The Nature Conservancy.
Non-native fish removed from the lake included channel and flathead catfish, carp, red shiners, green sunfish, mosquito fish and yellow bullheads. Officials salvaged sport fish to release elsewhere.
To their delight they found only one crawfish, non-natives that can be prolific throughout Arizona. They figure the increasing numbers of beavers and otters have helped take care of those pests.
Turtles and humpback chubs also will eat crayfish, Clark noted.
He predicted the chubs could do quite well in the lake if the Upper Verde gets some good flooding in the spring. The lack of natural flooding in 1998-2004 really hurt them, he said.
The researchers will install tracking devices on the newly released native fish so they can track their movements and growth, Sponholtz said.
"That's of tremendous value," she added.
Reader Comments
Posted: Sunday, August 23, 2009
Article comment by:
Allen James
A native fishery to what end? They can't be fished for sport so why all the effort? Just because they're "native" doesn't mean they are of higher value than smallmouth bass and cats. This is all spurred on by the tree huggers who have infiltrated game and fish. They don't want you using the Verde River. It's just to look at from your hiking trail!
Maybe they should start clearing Paulden of the "non natives" and make it more like America than a 3rd world country.
Posted: Saturday, August 22, 2009
Article comment by:
Joanne Oellers
This is wonderful news for the upper Verde River habitat. These natives are precious and deserve the fullest protection. Great work!
Posted: Saturday, August 22, 2009
Article comment by:
No name provided
this is wonderfull do we eat these fish what good are they. chanel cat, bass, and blue gill are useable.
