 |
|
New study shows greenback cutthroat trout involved in recovery effort misidentified
September 06, 2007A new study led by the University of Colorado at Boulder indicates biologists trying to save Colorado's native greenback cutthroat trout from extinction over the past several decades through hatchery propagation and restocking efforts have, in most cases, inadvertently restored the wrong fish.
According to a sophisticated DNA analysis, five of nine "relic" populations of what biologists believed to be greenback cutthroat trout living in isolated pockets of the state actually are Colorado River cutthroat trout, a closely related subspecies, said lead author Jessica Metcalf, a researcher in CU-Boulder's ecology and evolutionary biology department. Eggs and sperm from the trout populations have been used for the last several decades to rear new generations in hatcheries, allowing state biologists to restock parts of Colorado with what they thought were greenback cutthroats, she said.
The new study, which included sequencing and analyzing mitochondrial and nuclear DNA, showed the majority of the greenback populations had been misidentified, and that the greenback cutthroat trout range is now restricted to just 11 miles of streams in several remote areas of Colorado. The paper was published in the Aug. 28 online edition of the journal Molecular Ecology.
The misidentification likely was caused by the stocking of fish in the late 1800s and early 1900s when railroads delivered hundreds of thousands of baby trout around the state of various species and subspecies for people to stock in local waters, said Metcalf. "This illustrates the need for biologists to consider that the species may have been introduced by the industriousness of humans before the documentation of the native flora and fauna of the area was recorded," she said.
Co-authors on the study included Professor Andrew Martin and undergraduate student Jazzmin Jenkins of CU-Boulder, Victoria Pritchard and David Cowley of New Mexico State University, Sarah Silvestri and John Wood of Pisces Molecular LLC of Boulder and Paul Evans and Dennis Shiozawa of Brigham Young University.
Although greenback cutthroats were declared extinct in 1937 -- victims of mining pollution, fishing pressure and competition from other trout species -- several small populations were discovered in tributaries to the Arkansas River and South Platte River drainages in the 1950s, she said. Greenback cutthroats were added to the federal list of endangered species in 1978.
State and federal fish managers began taking eggs and sperm from what were believed to be surviving populations of pure greenback cutthroats in the 1970s, rearing them in hatcheries and returning them to native cutthroat habitat. The habitat -- small streams and lakes -- had been cleared of non-native fish species to heighten survivability of the greenbacks, said Metcalf.
"We have to remember that management decisions by federal and state fisheries biologists over the past decades were based on the best reports available by experts at the time," said Metcalf, who received her doctorate from CU-Boulder in ecology and evolutionary biology under Martin in August. "Fortunately, the data is becoming more accurate over time as genetic techniques improve and the peer review process is increasingly incorporated into scientific management strategies."
The Colorado Division of Wildlife reached its goal of 20 self-sustaining populations in 2006, positioning the greenback for removal from the list of federally protected species. "But the new study means that we have not reached the targeted management goals, and the species is no closer to being removed from the endangered species list than when it originally was listed," Martin said.
"Our results suggest greenback cutthroat trout within its native range is at a higher risk of extinction than ever before despite conservation activities spanning more than two decades," the authors wrote in Molecular Ecology.
"This is an incredibly sobering story, and it's not something we wanted to find," said Martin, the principal investigator on the research effort. "While some of us are worried these findings will give the greenback restoration program a black eye, we hope biologists and agencies have the will and resolve to take the necessary steps to recover this species before it is gone forever."
Four native species of cutthroat evolved in Colorado, including the greenback cutthroat, the Colorado River cutthroat, the Rio Grande Cutthroat in the San Luis Valley and the yellowfin cutthroat, historically found in the Twin Lakes region near Leadville in the Arkansas River drainage and now believed to be extinct.
University of Colorado at Boulder
The misidentification likely was caused by the stocking of fish in the late 1800s and early 1900s when railroads delivered hundreds of thousands of baby trout around the state of various species and subspecies for people to stock in local waters, said Metcalf. "This illustrates the need for biologists to consider that the species may have been introduced by the industriousness of humans before the documentation of the native flora and fauna of the area was recorded," she said.
Co-authors on the study included Professor Andrew Martin and undergraduate student Jazzmin Jenkins of CU-Boulder, Victoria Pritchard and David Cowley of New Mexico State University, Sarah Silvestri and John Wood of Pisces Molecular LLC of Boulder and Paul Evans and Dennis Shiozawa of Brigham Young University.
Although greenback cutthroats were declared extinct in 1937 -- victims of mining pollution, fishing pressure and competition from other trout species -- several small populations were discovered in tributaries to the Arkansas River and South Platte River drainages in the 1950s, she said. Greenback cutthroats were added to the federal list of endangered species in 1978.
State and federal fish managers began taking eggs and sperm from what were believed to be surviving populations of pure greenback cutthroats in the 1970s, rearing them in hatcheries and returning them to native cutthroat habitat. The habitat -- small streams and lakes -- had been cleared of non-native fish species to heighten survivability of the greenbacks, said Metcalf.
"We have to remember that management decisions by federal and state fisheries biologists over the past decades were based on the best reports available by experts at the time," said Metcalf, who received her doctorate from CU-Boulder in ecology and evolutionary biology under Martin in August. "Fortunately, the data is becoming more accurate over time as genetic techniques improve and the peer review process is increasingly incorporated into scientific management strategies."
The Colorado Division of Wildlife reached its goal of 20 self-sustaining populations in 2006, positioning the greenback for removal from the list of federally protected species. "But the new study means that we have not reached the targeted management goals, and the species is no closer to being removed from the endangered species list than when it originally was listed," Martin said.
"Our results suggest greenback cutthroat trout within its native range is at a higher risk of extinction than ever before despite conservation activities spanning more than two decades," the authors wrote in Molecular Ecology.
"This is an incredibly sobering story, and it's not something we wanted to find," said Martin, the principal investigator on the research effort. "While some of us are worried these findings will give the greenback restoration program a black eye, we hope biologists and agencies have the will and resolve to take the necessary steps to recover this species before it is gone forever."
Four native species of cutthroat evolved in Colorado, including the greenback cutthroat, the Colorado River cutthroat, the Rio Grande Cutthroat in the San Luis Valley and the yellowfin cutthroat, historically found in the Twin Lakes region near Leadville in the Arkansas River drainage and now believed to be extinct.
University of Colorado at Boulder
Trout Current Events and Trout News RSSNorthern brown bears discovered feeding on whitefish runs
The discovery of brown (grizzly) bears feeding on migrating broad whitefish in a stream in Mackenzie Delta region of the Northwest Territories has researchers advising increased care in petroleum extraction and infrastructure development within the area.
River flow and temperature limit trout numbers
Over a 23-year study, Javier Lobon-Cervia has found the mechanism that controls the number of salmonids found each year in Cantabrian rivers.
Half of the fish consumed globally is now raised on farms, study finds
Aquaculture, once a fledgling industry, now accounts for 50 percent of the fish consumed globally, according to a new report by an international team of researchers. And while the industry is more efficient than ever, it is also putting a significant strain on marine resources by consuming large amounts of feed made from wild fish harvested from the sea, the authors conclude.
Study reveals mounting evidence of fish oil's heart health benefits
There is mounting evidence that omega-3 fatty acids from fish or fish oil supplements not only help prevent cardiovascular diseases in healthy individuals, but also reduce the incidence of cardiac events and mortality in patients with existing heart disease.
Sick fish may get sicker
Entire populations of North American fish already are being affected by several emerging diseases, a problem that threatens to increase in the future with climate change and other stresses on aquatic ecosystems, according to a noted U.S. Geological Survey researcher giving an invited talk on this subject today at the Wildlife Disease Association conference in Blaine, Wash.
Urban water ecology at the ESA annual meeting
Increasingly, human urban development overlaps with habitat for wild animals and plants, creating environments that degrade natural landscapes.
MIT: Extending the shelf life of antibody drugs
A new computer model developed at MIT can help solve a problem that has plagued drug companies trying to develop promising new treatments made of antibodies: Such drugs have a relatively short shelf life because they tend to clump together, rendering them ineffective.
Improved method developed to test carcinogen risk
Researchers at Oregon State University recently completed the largest animal study ever done in the field of toxicology, and the findings challenge some basic concepts about how to determine what level of a cancer-causing compound can be considered safe.
Berkeley Lab Scientists Contribute to Major New Report Describing Climate Change Impacts on the U.S.
Two researchers at the U.S. Department of Energy's Lawrence Berkeley National Laboratory (Berkeley Lab), Evan Mills and Michael Wehner, contributed to the analysis of the effects of climate change on all regions of the United States, described in a major report released today by the multi-agency U.S. Global Change Research Program.
Hatchery fish may hurt efforts to sustain wild salmon runs
Steelhead trout that are originally bred in hatcheries are so genetically impaired that, even if they survive and reproduce in the wild, their offspring will also be significantly less successful at reproducing.
More Trout Current Events and Trout News Articles
 |
Trout by Ray Bergman (Author) Trout is arguably the finest single volume ever produced on how, why, and where to catch trout. In spite of being originally published in 1938 (Penn Publishing Company), it remains utterly relevant. |
 |
Schubert: "Trout " Quintet Yo-Yo Ma (Performer), Franz Schubert (Performer), Edgar Meyer (Performer), Emanuel Ax (Performer), Rebecca Young (Performer), Pamela Frank (Performer) Schubert Trout Quintet |
 |
Trout: An Illustrated History by James Prosek (Author) 68 full-color plates. |
 |
Trout Grass Starring: David James Duncan This unique film documents the transformation of bamboo from a hardy species of grass into a meticulously crafted split-cane fly rod. Shot on location in the lush forests of Southern China and the majestic rivers of Montana, Trout Grass captures the allure of craftsmanship and rivers as well as the notion that fishing is about much more than catching fish. |
 |
Trout: The Complete Guide to Catching Trout with Flies, Artificial Lures and Live Bait (The Freshwater Angler) by Dick Sternberg (Author) To consistently catch trout in any body of water, you have to be versatile. On some days trout rise quickly to take dry flies. But on other days they respond better to nymphs, spawn bags or small spinners. This book explains how to choose the right presentation for any situation you encounter on your favorite stream. Hall of Fame angler Tony Dean says, "This book provided me the knowledge I needed to catch more trout in streams and it will help you do the same." |
 |
Alaska Smokehouse Wood Pencil Box With One Each Salmon, Shrimp & Salmon, And Trout, 10.5 Ounce Box by Alaska Smokehouse |
|
Trout Adult T-Shirt / Black size Adult X-Large by N/A | |
 |
Cold Steel 20BTJ Bird & Trout Knife by Cold Steel The Bird and Trout has been treasured by hunters and fishermen for generations. Ultra slim profile, and unique all steel construction. The skeletonized handle offers great versatility and freedom of movement. The ring allows the knife to hang from the little finger when not in use and yet remain instantly available. Comes with a light weight Concealex neck sheath and steel bead chain lanyard. |
 |
The Outsider by Walter Trout The Outsider has been all about commitment: From Walter's desire to create songs that speak to the soul as well as the mind, the producer (John Porter), who added his musical experience creating a partnership in finding the best possible expression for Walter's intentions, to the musicians who each in their own expert way added a unique and strong statement - there has been a unique sense of team work throughout, filling Walter with a thankfulness to be able to surround himself with people of so much talent. Walter Trout is a blues guitarist, singer and songwriter of his own band. |
 |
About Trout: The Best of Robert Behnke from Trout Magazine by Robert J. Behnke PhD (Author) Trout Unlimited, the national cold-water conservation group with membership of more than 152,000, has featured Robert Behnke in its quarterly magazine, Trout, for more than twenty years. Professor of ichthyology at Colorado State University, Behnke is our nation’s pre-eminent authority on trout biology, as well as a conservationist and superb fisherman. Known as “The Trout Doctor,” Behnke writes about topics such as native species introductions, genetic markers, endangered species, improving habitats, angling tips, and improved conservation in the wake of the efforts of Trout Unlimited. Illustrated with full-color images throughout by world-renowned fish artist Joseph Tomelleri, this book is the collection of Behnke’s best columns and most meaningful insights about trout, the... |
| © 2009 BrightSurf.com |