Featured Research

from universities, journals, and other organizations

Farm salmon pose clear reproductive threat to wild gene pools, researchers say

Date:
March 10, 2014
Source:
University of East Anglia
Summary:
While farmed salmon are genetically different to their wild counterparts, they are just as fertile. This is important information because millions of farmed salmon escape into the wild -- posing threats to wild gene pools. The research team of a new study says farmed salmon should be sterilized to protect wild gene pools.

Findings published today reveal that, while farmed salmon are genetically different to their wild counterparts, they are just as fertile. This is important information because millions of farmed salmon escape into the wild -- posing threats to wild gene pools.

Lead Researcher Prof Matt Gage from UEA's school of Biological Sciences said: "Around 95 per cent of all salmon in existence are farmed, and domestication has made them very different to wild populations, each of which is locally adapted to its own river system.

"Farmed salmon grow very fast, are aggressive, and not as clever as wild salmon when it comes to dealing with predators. These domestic traits are good for producing fish for the table, but not for the stability of wild populations.

"The problem is that farmed salmon can escape each year in their millions, getting into wild spawning populations, where they can then reproduce and erode wild gene pools, introducing these negative traits.

"We know that recently-escaped farmed salmon are inferior to wild fish in reproduction, but we do not have detailed information on sperm and egg performance, which could have been affected by domestication. Our work shows that farm fish are as potent at the gamete level as wild fish, and if farm escapes can revive their spawning behaviour by a period in the wild, clearly pose a significant threat of hybridisation with wild populations."

Researchers used a range of in vitro fertilization tests in conditions that mimicked spawning in the natural environment, including tests of sperm competitiveness and egg compatibility. All tests on sperm and egg form and function showed that farmed salmon are as fertile as wild salmon -- identifying a clear threat of farmed salmon reproducing with wild fish.

"Some Norwegian rivers have recorded big numbers of farmed fish present -- as much as 50 per cent. Both anglers and conservationists are worried by farmed fish escapees which could disrupt locally adapted traits like timing of return, adult body size, and disease resistance.

"Salmon farming is a huge business in the UK, Norway and beyond, and while it does reduce the pressure on wild fish stocks, it can also create its own environmental pressures through genetic disruption.

"A viable solution is to induce 'triploidy' by pressure-treating salmon eggs just after fertilisation -- where the fish grows as normal, but with both sex chromosomes; this is normal for farming rainbow trout. The resulting adult develops testes and ovaries but both are much reduced and most triploids are sterile. These triploid fish can't reproduce if they escape, but the aquaculture industry has not embraced this technology yet because of fears that triploids don't perform as well in farms as normal diploid fish, eroding profits."


Story Source:

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


Journal Reference:

  1. Sarah E. Yeates, Sigurd Einum, Ian A. Fleming, William V. Holt, Matthew J.G. Gage. Assessing risks of invasion through gamete performance: farm Atlantic salmon sperm and eggs show equivalence in function, fertility, compatibility and competitiveness to wild Atlantic salmon. Evolutionary Applications, 2014; DOI: 10.1111/eva.12148

Cite This Page:

University of East Anglia. "Farm salmon pose clear reproductive threat to wild gene pools, researchers say." ScienceDaily. ScienceDaily, 10 March 2014. <www.sciencedaily.com/releases/2014/03/140310090927.htm>.
University of East Anglia. (2014, March 10). Farm salmon pose clear reproductive threat to wild gene pools, researchers say. ScienceDaily. Retrieved September 2, 2014 from www.sciencedaily.com/releases/2014/03/140310090927.htm
University of East Anglia. "Farm salmon pose clear reproductive threat to wild gene pools, researchers say." ScienceDaily. www.sciencedaily.com/releases/2014/03/140310090927.htm (accessed September 2, 2014).

Share This




More Plants & Animals News

Tuesday, September 2, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

We've Got Mites Living In Our Faces And So Do You

We've Got Mites Living In Our Faces And So Do You

Newsy (Aug. 30, 2014) A new study suggests 100 percent of adult humans (those over 18 years of age) have Demodex mites living in their faces. Video provided by Newsy
Powered by NewsLook.com
Washington Wildlife Center Goes Nuts Over Baby Squirrels

Washington Wildlife Center Goes Nuts Over Baby Squirrels

Reuters - US Online Video (Aug. 30, 2014) An animal rescue in Washington state receives an influx of orphaned squirrels, keeping workers busy as they nurse them back to health. Rough Cut (no reporter narration). Video provided by Reuters
Powered by NewsLook.com
Experimental Ebola Drug ZMapp Cures Lab Monkeys Of Disease

Experimental Ebola Drug ZMapp Cures Lab Monkeys Of Disease

Newsy (Aug. 29, 2014) In a new study, a promising experimental treatment for Ebola managed to cure a group of infected macaque monkeys. Video provided by Newsy
Powered by NewsLook.com
Killer Amoeba Found in Louisiana Water System

Killer Amoeba Found in Louisiana Water System

AP (Aug. 28, 2014) State health officials say testing has confirmed the presence of a killer amoeba in a water system serving three St. John the Baptist Parish towns. (Aug. 28) 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