![]() “It’s really difficult to wrap your brain around what these fish used to have access to,” Pennock said. On the other hand, removing the blockade could also allow a whole new batch of invasive species, such as channel catfish and small mouth bass, into the upper reaches of the San Juan.Ĭasey Pennock, a doctoral student in the division of biology at Kansas State University who took part in the research, will take the findings a step further, analyzing how fish have adapted to living in Lake Powell.įish, which once could travel freely from Baja California to the Colorado Rocky Mountains, have a whole new underwater landscape to navigate, and understanding how they survive is important to keeping them alive, he said. Removing the waterfall would allow the razorback and other native fish renewed access to the San Juan, and it could create a channel for future sediment flows farther downstream. “That’s a 500-, 600-mile trip for a fish up until now we thought was fairly sedentary,” McKinstry said.īut there are serious implications when considering creating a fish passage or removing the waterfall. Through the tagging system, researchers found some razorbacks at the base of the San Juan River waterfall originated in the White and Gunnison rivers, a colossal voyage down the Colorado River and across Lake Powell. Over a three-year period, from 2015 to 2017, nearly 1,500 razorback suckers were detected downstream of the waterfall – a momentous number considering the overall population is estimated at 2,000 to 4,000 fish, McKinstry said. In that time span, the antenna tracked more than 450 endangered razorbacks, McKinstry said. The group took a trip down to the waterfall, where the new antenna had been placed two weeks earlier. McKinstry remembers the date of the “aha moment” when researchers knew the technology was a success: March 9, 2015. “Until we could throw this (antenna) in there, those fish were a lost population up in the San Juan.” “All of a sudden, we were able to get information from areas where we couldn’t before,” MacKinnon said. Peter MacKinnon, a research scientist at Utah State University, helped develop an antenna that, while fully submerged in water, can detect the tags placed on razorback suckers. Then, a new take on existing technology allowed for a major breakthrough. The San Juan River’s original path is buried under this thick layer of sediment, about 3 miles away from where it now flows.īut for years, the old methods of surveying fish populations didn’t work in the remote area where the waterfall is, either a 2½ hour drive from Mexican Hat, Utah, or a 100-mile boat ride from Bullfrog Marina in Lake Powell. It’s estimated that sediment deposits in the San Juan River confluence area are about 80 feet thick.īut when water levels in reservoirs drop, as is the case at Lake Powell, the incoming rivers form new paths that cut through the deposited sediment. When dams are built, rivers that flow into the reservoir deposit tons of sediment at the mouth of the delta. The waterfall – known as the Piute Farm’s Waterfall – is relatively new, created both by the rise of Lake Powell’s waters and their decline in recent years However, it’s estimated that only 2,000 to 4,000 razorbacks live in the San Juan River below Navajo Dam and above Lake Powell.īut years ago, McKinstry’s attention was drawn to a unique and extremely remote waterfall on the San Juan River, upstream of Lake Powell and about 3 miles downstream of the Clay Hills take-out for boaters. This allows researchers to recapture fish and collect a variety of metrics about the success of stocking, such as population numbers, survival rates and migration habits.Įvery year, about 10,000 razorbacks are stocked near Farmington, McKinstry said. Each fish is given a tag, much like those implanted in pets, to track its movements throughout the watershed. These pressures decimated razorbacks on the San Juan River, which starts in southern Colorado, flows through a sliver of northern New Mexico and down to its confluence with Lake Powell in Utah.Īs a result, the San Juan River Basin Recovery Implementation Program was created to offset the impacts of water-use developments by re-establishing two impaired species of fish: the razorback and Colorado pike minnow.Īs part of the recovery program, razorback suckers are raised in hatcheries and stocked in the San Juan River. Once widespread and abundant, the razorback sucker was listed as an endangered species in the early 1990s after being driven to near extinction by over-fishing, the introduction of non-native species and the installation of dams. “We assumed they were dead or lost to Lake Powell,” said Mark McKinstry, a research biologist for the Bureau of Reclamation. At a little known waterfall on a remote part of the San Juan River, more than a thousand endangered fish, previously unaccounted for, have been found in populations that are thriving – a potentially groundbreaking discovery.
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