Featured Research

from universities, journals, and other organizations

Using genetics to measure environmental impact of salmon farming

Date:
May 8, 2014
Source:
Université de Genève
Summary:
Determining species diversity makes it possible to estimate the impact of human activity on marine ecosystems accurately. The environmental effects of salmon farming have been assessed, until now, by visually identifying the animals living in the marine sediment samples collected at specific distances from farming sites. A team of researchers analyzed this type of sediment using a technique known as 'DNA barcoding' that targets certain micro-organisms.

This image shows 0.3 mm foraminifera made up of a single cell surrounded by a limestone shell.
Credit: © Jan Pawlowski, UNIGE

Determining species diversity makes it possible to estimate the impact of human activity on marine ecosystems accurately. The environmental effects of salmon farming have been assessed, until now, by visually identifying the animals living in the marine sediment samples collected at specific distances from farming sites. A team led by Jan Pawlowski, professor at the Faculty of Science of the University of Geneva (UNIGE), Switzerland, analysed this type of sediment using a technique known as "DNA barcoding" that targets certain micro-organisms. Their research, which has been published in the Molecular Ecology Resources journal, reveals the potential of this new genomic tool for detecting environmental changes as accurately as with traditional methods -- but more quickly and at lower cost.

Salmon farming is one of the most widespread activities in marine aquaculture. It has a considerable impact on the environment, which is largely due to three factors: the accumulation of food waste and faecal matter; the toxicity caused by the chemicals employed to clean the cages; and the drugs that are used.

The impact of such farms on the coastal environment is traditionally assessed by monitoring some of the small species that live in the sediments beneath the cages. The visual identification of these animals under a microscope is time consuming and extremely expensive. It also requires highly-trained taxonomy specialists, which renders the method unsuitable for large-scale use. But, as Jan Pawlowski, professor in the Department of Genetics and Evolution at UNIGE, explains: "It is now possible to address this problem using sophisticated tools that analyse the DNA and RNA extracted from sediment samples."

Genetic barcodes

Working alongside researchers from the Scottish Association of Marine Sciences (UK) and the University of Aarhus (Denmark), Pawlowski collected sediment samples at specific distances from two salmon farms in the heart of the Scottish fjords. "We used genetic barcodes that recognise specific fragments of DNA and RNA extracted from the sediment samples," explains researcher Franck Lejzerowicz, a PhD student in the professor's team: "These 'genetic hooks' consist of DNA sequences that vary between species but remain stable within a given species."

The DNA barcodes used make it possible to identify the different foraminiferal species that are present in the sediments. These single-celled micro-organisms, which have a great diversity, are already recognised environmental bioindicators. As a result, the geneticists were able to process a large number of samples using high-throughput DNA sequencing. "Our study revealed large variations between foraminiferal species collected near farms and those from remote sites. In addition, species diversity diminishes on sites affected by the farms."

Monitoring the quality of the environment

This type of highly-accurate ecological analysis allowed to establish a correlation between species richness and distance from the cages, a correlation that is even more pronounced if the farm is only stirred by weak sea currents. The same type of correlation was also established based on the degree of oxygenation of the sediments. As Jan Pawlowski states: "The vast amount of organic compounds on the farming sites can even sometimes generate anoxic sediments, which makes it impossible for most species to survive." The biologists were also surprised to discover a new species of foraminifera, which could serve as a bioindicator of organic enrichment.

This technology, known as "metabarcoding," is spreading rapidly, and can be used to supply information on the overall diversity of the micro-organisms found in all samples. The method is suitable for large-scale tests because it is much quicker, more reliable and easier to standardise than the processes that are used at present. This study is one of the first attempts to use environmental genomics as a tool for assessing the impact of industries such as marine aquaculture or offshore drilling.


Story Source:

The above story is based on materials provided by Université de Genève. Note: Materials may be edited for content and length.


Journal Reference:

  1. Jan Pawlowski, Philippe Esling, Franck Lejzerowicz, Tomas Cedhagen, Thomas A. Wilding. Environmental monitoring through protist next-generation sequencing metabarcoding: assessing the impact of fish farming on benthic foraminifera communities. Molecular Ecology Resources, 2014; DOI: 10.1111/1755-0998.12261

Cite This Page:

Université de Genève. "Using genetics to measure environmental impact of salmon farming." ScienceDaily. ScienceDaily, 8 May 2014. <www.sciencedaily.com/releases/2014/05/140508121357.htm>.
Université de Genève. (2014, May 8). Using genetics to measure environmental impact of salmon farming. ScienceDaily. Retrieved October 22, 2014 from www.sciencedaily.com/releases/2014/05/140508121357.htm
Université de Genève. "Using genetics to measure environmental impact of salmon farming." ScienceDaily. www.sciencedaily.com/releases/2014/05/140508121357.htm (accessed October 22, 2014).

Share This



More Plants & Animals News

Wednesday, October 22, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Cadaver Dogs Aid Search for More Victims of Suspected Indiana Serial Killer

Cadaver Dogs Aid Search for More Victims of Suspected Indiana Serial Killer

Reuters - US Online Video (Oct. 21, 2014) — Police in Gary, Indiana are using cadaver dogs to search for more victims after a suspected serial killer confessed to killing at least seven women. Linda So reports. Video provided by Reuters
Powered by NewsLook.com
White Lion Cubs Unveiled to the Public

White Lion Cubs Unveiled to the Public

Reuters - Light News Video Online (Oct. 21, 2014) — Visitors to Belgrade zoo meet a pair of three-week-old lion cubs for the first time. Tara Cleary reports. Video provided by Reuters
Powered by NewsLook.com
'Cadaver Dog' Sniffs out Human Remains

'Cadaver Dog' Sniffs out Human Remains

AP (Oct. 21, 2014) — Where's a body buried? Buster's nose can often tell you. He's a cadaver dog, specially trained to find human remains and increasingly being used by law enforcement and accepted in courts. These dogs are helping solve even decades-old mysteries. (Oct. 21) Video provided by AP
Powered by NewsLook.com
White Lion Cubs Born in Belgrade Zoo

White Lion Cubs Born in Belgrade Zoo

AFP (Oct. 20, 2014) — Two white lion cubs, an extremely rare subspecies of the African lion, were recently born at Belgrade Zoo. They are being bottle fed by zoo keepers after they were rejected by their mother after birth. Duration: 00:42 Video provided by AFP
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