'So long, suckers' no longer true in Grand Canyon
The razorback sucker, thought to have disappeared from the Grand Canyon in the 1990s, has been rediscovered there by researchers, who believe conditions are right for naturally reproducing populations. (BLM/Courtesy)
6/25/2014 6:02:00 AM
WASHINGTON - Researchers have found evidence that razorback suckers, once thought to have disappeared from the Grand Canyon, have moved upriver from Lake Mead and are successfully reproducing in the canyon, the Interior Department announced last week.
The endangered fish was last seen in the canyon in the 1990s. The discovery of larval fish there now indicates that conditions are right for naturally reproducing populations of the fish to return, researchers said.
"It's exciting to see an endangered species doing what it's supposed to do," said Howard Brandenburg, a fisheries biologist with American Southwest Ichthyological Researchers LLC. "So many negative impacts that they're dealing with all the time, so it's nice to see expansion."
Brandenburg's firm worked with the National Park Service, the Bureau of Reclamation and Bio-West Inc. to release nine tagged adult fish in the Colorado River in March. Adult fish can reach 3 feet, but surveys in April and May discovered larval fish and confirmed spawning in the area, the Interior Department said.
Brandenburg said the released fish were all males, so the larval fish that have since been discovered could not have been the product solely of the release.
Brandon Albrecht, senior fisheries biologist at Bio-West, said the company began monitoring razorback suckers in Lake Mead several years ago, but expanded north after data from tagged fish suggested they were spending time in the canyon reaches of the Colorado.
"We're starting to process samples and understand the movement data," he said. "There are a lot of questions as to how far up they go and why."
Brandenburg said the temperature, shallowness, low current and large, clean rocks in that part of the river make for good breeding conditions for the sucker.
Albrecht said the next step is to study whether there is recruitment - a fish's progression from larva to reproductive adult - and to keep studying results from previous samples.
Bill Stewart, the aquatic research program manager at the Arizona Game and Fish Department, said the discovery of larval and juvenile razorback suckers is not surprising. He said in the last two years the department has observed adult fish in the Grand Canyon, so finding young razorback suckers was just something new.
Bureau of Reclamation Biologist Dave Speas said the bureau was required under a 2007 agreement to help fund research into the feasibility of reintroducing razorback suckers to the lower Grand Canyon.
He said the partnering groups have scheduled at least six more trips this year to collect data.
"We are very excited to collaborate with state, federal tribal and private sector partners," Speas said. "It is a surprising and encouraging result."
Sandy Bahr, director of the Sierra Club's Grand Canyon Chapter, welcomed the restoration of the native fish species.
"Anytime that a native plant or animal can be restored, especially to places like national parks, we celebrate that," she said.
Despite the fact that its population dwindled because of dams and nonnative fish, Bahr said this discovery is a testament to the razorback sucker's "resiliency."
"If you're a native fish in Arizona, you have adapted to some pretty remarkable conditions," she said. "We hear so much in Arizona about nonnative fish, but here's an opportunity for people to get to know a little bit about one of our native species."