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.

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 April 18, 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 April 18, 2014).

Share This



More Plants & Animals News

Friday, April 18, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

The Great British Farmland Boom

The Great British Farmland Boom

Reuters - Business Video Online (Apr. 17, 2014) — Britain's troubled Co-operative Group is preparing to cash in on nearly 18,000 acres of farmland in one of the biggest UK land sales in decades. As Ivor Bennett reports, the market timing couldn't be better, with farmland prices soaring over 270 percent in the last 10 years. Video provided by Reuters
Powered by NewsLook.com
Flamingo Frenzy Ahead of Zoo Construction

Flamingo Frenzy Ahead of Zoo Construction

AP (Apr. 17, 2014) — With plenty of honking, flapping, and fluttering, more than three dozen Caribbean flamingos at Zoo Miami were rounded up today as the iconic exhibit was closed for renovations. (April 17) Video provided by AP
Powered by NewsLook.com
Change of Diet Helps Crocodile Business

Change of Diet Helps Crocodile Business

Reuters - Business Video Online (Apr. 16, 2014) — Crocodile farming has been a challenge in Zimbabwe in recent years do the economic collapse and the financial crisis. But as Ciara Sutton reports one of Europe's biggest suppliers of skins to the luxury market has come up with an unusual survival strategy - vegetarian food. Video provided by Reuters
Powered by NewsLook.com
Could Even Casual Marijuana Use Alter Your Brain?

Could Even Casual Marijuana Use Alter Your Brain?

Newsy (Apr. 16, 2014) — A new study conducted by researchers at Northwestern and Harvard suggests even casual marijuana use can alter your brain. Video provided by Newsy
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