Project To Restore Native Fish

October 22, 2009

Release from: Sarah Mundy
JackCentral.com

Federal biologists proposed an aquatic restoration project to rid the West Fork of Oak Creek of non-native fish that have invaded the territory and could possibly be harming the native fish.

The proposal is to build a temporary barrier to separate the native aquatic wildlife and use a specific type of fish-pesticide, or piscicide, that has been used for centuries in South America to selectively kill non-native gilled animals.

The native and currently endangered fish, which are being sought after specifically by biologists, will be captured and held during the period of time it takes for the non-native species to die off from the piscicide, a chemical called rotenone.

Janie Agyagos, a district wildlife biologist of the Red Rock Ranger District, said she believes the project is greatly beneficial for local ecosystems. She explained there would be very little impact on the local environment during the restoration project, and any impact that does occur would be completely unnoticeable after two years.

“[The U.S. Forest Service] is trying to restore an aquatic system back to its natural environment,” Agyagos said. “Non-native fish species have been introduced to all bodies of water within Arizona. It is impossible to electroshock, fish or catch enough to eradicate all of the invasive species of fish.”

Sandy Bahr, the Conservation Outreach director for the Grand Canyon chapter of the Sierra Club, said the piscicide is not quite as benign as the government lead us to believe, but not nearly as malevolent as laymen are thinking. Bahr said the two main problems with this plan are the potential harm caused to the macroinvertebrates, such as the insects the fish eat to survive and the people who attempt to re-stock Oak Creek with non-native fish.

“If this is not done properly, it could be a disaster,” Bahr said. “They will need to ensure the creek is not re-contaminated with non-native fish and that the rotenone will not be able to contaminate the rest of the creek downstream.”

Agyagos said the barrier itself should not affect upland vegetation at all, though the cattails and some saplings and seedlings less than nine inches in diameter will be inundated with the four-and-a-half foot high waters held back briefly by the barrier. The water will be able to flow over the barrier and then be treated at three separate locations to prevent the piscicide from entering the rest of the stream’s path.

According to the U.S. Department of Agriculture, rotenone is a naturally occurring substance derived from the roots of tropical plants and only affects gilled animals. The piscicide is not the type of poison commonly shown in popular culture, which decimates all living things, but rather it specifies in preventing the oxygen from being processed at a cellular level in gilled creatures such as fish, macroinvertabrates, zooplankton and amphibian larvae. No birds or mammals have ever been reported as being affected by this piscicide.

“We are supportive of restoring and recovering native fisheries throughout Arizona, but projects such as these do present a dilemma and [this is] certainly an important time to review the precautionary principle of ‘first do no harm,’” Bahr said. “That being said, we also recognize that the plight of our native fishes is desperate, and that there are no easy answers in seeking their restoration and recovery.”

Travis Burbie, a sophomore chemistry major, said restoring the West Fork should not be such a high priority.

“While I believe that it’s great that we are trying to put nature back to the way it was before we interfered, it appears that natural selection has chosen to put these fish to extinction, even if we helped speed that process along by introducing non-native species,” Burbie said. “I hate that we as a people are spending money so recklessly, especially as we are still in an economic recession.”