Featured Research

from universities, journals, and other organizations

Efforts To Save Greenback Cutthroat Trout Snagged: Wrong Fish Restocked For Decades

Date:
September 11, 2007
Source:
University of Colorado at Boulder
Summary:
A new study 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.

A new University of Colorado at Boulder study has shown biologists trying to spur the recovery of the threatened greenback cutthroat trout in Colorado, have in many cases been restocking the wrong subspecies of trout into small streams and lakes in the state.
Credit: Colorado Division of Wildlife

A 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 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.

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.

The paper was published in the Aug. 28 online edition of the journal Molecular Ecology. 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.

The study was funded by the National Science Foundation, the Colorado Division of Wildlife, the U.S. Fish and Wildlife Service, CU-Boulder and a number of other federal and state agencies.


Story Source:

The above story is based on materials provided by University of Colorado at Boulder. Note: Materials may be edited for content and length.


Cite This Page:

University of Colorado at Boulder. "Efforts To Save Greenback Cutthroat Trout Snagged: Wrong Fish Restocked For Decades." ScienceDaily. ScienceDaily, 11 September 2007. <www.sciencedaily.com/releases/2007/09/070905133602.htm>.
University of Colorado at Boulder. (2007, September 11). Efforts To Save Greenback Cutthroat Trout Snagged: Wrong Fish Restocked For Decades. ScienceDaily. Retrieved July 29, 2014 from www.sciencedaily.com/releases/2007/09/070905133602.htm
University of Colorado at Boulder. "Efforts To Save Greenback Cutthroat Trout Snagged: Wrong Fish Restocked For Decades." ScienceDaily. www.sciencedaily.com/releases/2007/09/070905133602.htm (accessed July 29, 2014).

Share This




More Plants & Animals News

Tuesday, July 29, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Deadly Ebola Virus Threatens West Africa

Deadly Ebola Virus Threatens West Africa

AP (July 28, 2014) West African nations and international health organizations are working to contain the largest Ebola outbreak in history. It's one of the deadliest diseases known to man, but the CDC says it's unlikely to spread in the U.S. (July 28) Video provided by AP
Powered by NewsLook.com
Traditional African Dishes Teach Healthy Eating

Traditional African Dishes Teach Healthy Eating

AP (July 28, 2014) Classes are being offered nationwide to encourage African Americans to learn about cooking fresh foods based on traditional African cuisine. The program is trying to combat obesity, heart disease and other ailments often linked to diet. (July 28) Video provided by AP
Powered by NewsLook.com
Asteroid's Timing Was 'Colossal Bad Luck' For The Dinosaurs

Asteroid's Timing Was 'Colossal Bad Luck' For The Dinosaurs

Newsy (July 28, 2014) The asteroid that killed the dinosaurs struck at the worst time for them. A new study says that if it hit earlier or later, they might've survived. Video provided by Newsy
Powered by NewsLook.com
Raw: Sea Turtle Hatchlings Emerge from Nest

Raw: Sea Turtle Hatchlings Emerge from Nest

AP (July 27, 2014) A live-streaming webcam catches loggerhead sea turtle hatchlings emerging from a nest in the Florida Keys. (July 27) Video provided by AP
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins