Featured Research

from universities, journals, and other organizations

Conservation of genetic structure in lake salmonids affected by hydropower regulation, release of fish and hybrids

Date:
June 28, 2011
Source:
Norwegian School of Veterinary Science
Summary:
The negative effects of releasing fish and the possible fragmentation of natural fish stocks in connection with hydropower regulations may be fewer than at first feared. New research shows that the genetic structure of established stocks of wild trout and charr is only affected to a small extent by human intervention in the study area.

The negative effects of releasing fish and the possible fragmentation of natural fish stocks in connection with hydropower regulations may be fewer than at first feared.
Credit: Image courtesy of Norwegian School of Veterinary Science

The negative effects of releasing fish and the possible fragmentation of natural fish stocks in connection with hydropower regulations may be fewer than at first feared.

Related Articles


Jens Wollebæk's doctoral thesis shows that the genetic structure of established stocks of wild trout and charr is only affected to a small extent by human intervention in the study area.

Released fish often have a different genetic structure to that of wild fish and can pose a threat to the natural, genetic structure of wild fish stocks. By means of DNA analyses, Wollebæk has studied genetic variation in trout and charr living in two mountain reservoirs in the county of Buskerud, Norway.Since 1919, the ecosystem has been greatly affected by hydropower regulations and the subsequent release of large numbers of trout. In addition, an unintended colonisation of charr and minnows has occurred.

Released trout accounted for nearly 30% of the sexually mature fish in the reservoirs and it was assumed that the prolonged use of non-indigenous and previously released fish in hatcheries posed a risk to the genetic integrity of wild fish. However, it appears that wild fish maintain their natural, genetic structure, principally due to the high mortality of indigenous and released hybrids and to the fact that released fish do not migrate when spawning. Wollebæk's research shows that the genetic material of natural fish stocks is most affected by natural gene flow between nearby, wild substocks of trout within comparable habitats in the reservoirs studied.

Variations in water flow impinge on the life history strategy of the trout and charr to a greater extent than migration barriers introduced by humans. Nevertheless, the reproductive behaviour of trout and charr has changed since the introduction of charr and minnows. Wollebæk's thesis reveals the rate and degree of change in the genetic structure of both trout and charr.

Indigenous stocks of lake trout and growing, reproductive barriers between populations of charr established in stable habitats during the last century point to the capacity of salmonids to survive and adapt to changing environmental conditions. Wollebæk's doctoral thesis shows how genetic and ecological variation builds a foundation for selection and is a decisive factor in the establishment of alien species and the preservation of reproductive barriers. For this reason, both genetic and ecological criteria should be taken into account when managing fish stocks and regulating watercourses for hydropower purposes.

Cand.scient. Jens Wollebæk defended his doctoral thesis on 27th June 2011 at The Norwegian School of Veterinary Science. The thesis is entitled: "Gene flow resilience in alpine lake salmonids: a conservation perspective."


Story Source:

The above story is based on materials provided by Norwegian School of Veterinary Science. Note: Materials may be edited for content and length.


Cite This Page:

Norwegian School of Veterinary Science. "Conservation of genetic structure in lake salmonids affected by hydropower regulation, release of fish and hybrids." ScienceDaily. ScienceDaily, 28 June 2011. <www.sciencedaily.com/releases/2011/06/110628094827.htm>.
Norwegian School of Veterinary Science. (2011, June 28). Conservation of genetic structure in lake salmonids affected by hydropower regulation, release of fish and hybrids. ScienceDaily. Retrieved November 28, 2014 from www.sciencedaily.com/releases/2011/06/110628094827.htm
Norwegian School of Veterinary Science. "Conservation of genetic structure in lake salmonids affected by hydropower regulation, release of fish and hybrids." ScienceDaily. www.sciencedaily.com/releases/2011/06/110628094827.htm (accessed November 28, 2014).

Share This


More From ScienceDaily



More Plants & Animals News

Friday, November 28, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Research on Bats Could Help Develop Drugs Against Ebola

Research on Bats Could Help Develop Drugs Against Ebola

AFP (Nov. 28, 2014) — In Africa's only biosafety level 4 laboratory, scientists have been carrying out experiments on bats to understand how virus like Ebola are being transmitted, and how some of them resist to it. Duration: 01:18 Video provided by AFP
Powered by NewsLook.com
New Dinosaur Species Found in Museum Collection

New Dinosaur Species Found in Museum Collection

Reuters - Innovations Video Online (Nov. 27, 2014) — A British palaeontologist has discovered a new species of dinosaur while studying fossils in a Canadian museum. Pentaceratops aquilonius was related to Triceratops and lived at the end of the Cretaceous Period, around 75 million years ago. Jim Drury has more. Video provided by Reuters
Powered by NewsLook.com
Tryptophan Isn't Making You Sleepy On Thanksgiving

Tryptophan Isn't Making You Sleepy On Thanksgiving

Newsy (Nov. 27, 2014) — Tryptophan, a chemical found naturally in turkey meat, gets blamed for sleepiness after Thanksgiving meals. But science points to other culprits. Video provided by Newsy
Powered by NewsLook.com
Classic Hollywood Memorabilia Goes Under the Hammer

Classic Hollywood Memorabilia Goes Under the Hammer

Reuters - Entertainment Video Online (Nov. 26, 2014) — The iconic piano from "Casablanca" and the Cowardly Lion suit from "The Wizard of Oz" fetch millions at auction. Sara Hemrajani reports. Video provided by Reuters
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:

Strange & Offbeat Stories

 

Plants & Animals

Earth & Climate

Fossils & Ruins

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