Navigation Links
Salmon farms kill wild fish, study shows

New research confirms that sea lice from fish farms kill wild salmon. Up to 95 per cent of the wild juvenile salmon that migrate past fish farms die as a result of sea lice infestation from the farms. The results of the research have been published in the Proceedings of the National Academy of Sciences of The United States of America.

"We know that fish farms raise sea lice levels, and we know that sea lice kill fish," said the study's lead author Martin Krkosek, a Ph.D. student at the University of Alberta Centre for Mathematical Biology. "This is the first study to combine field surveys, experiments and mathematical modeling in one system to estimate the total impact of the farms."

The primary sea lice hosts are adult salmon. Under natural conditions, the adults are far offshore when the juveniles are migrating out to sea. Fish farms put adult salmon in net pens along the migration routes. The result is a cloud of sea lice through which the juveniles must migrate. "It takes only one or two sea lice to kill a juvenile pink or chum salmon," said Krkosek. "The juveniles are so vulnerable because they are so small ?only one to two inches long."

"We often worry about wildlife making humans sick, but here is a case where humans are making wildlife sick," said study co-author Dr. Mark Lewis, a mathematician and biologist at the University of Alberta.

The study found an increasing number of salmon were killed over the migration season, from 9 per cent in early spring when the sea lice population was low to 95 per cent in late spring when the sea lice population was higher.

"Everyone knows that only a small fraction of juvenile salmon survive to return as adults," said Lewis. "The fish-farm sea lice are reducing that fraction even more."

The research was conducted by a team of biologists and mathematicians working in coastal British Columbia. "We counted sea lice on more than 14 thousand juvenile salmon migrating past fi sh farms, and conducted mortality experiments with more than 3,000 fish," said Krkosek. "We then used mathematical models to combine this information and estimate the total impact of the farms."

"The work is of an impeccably high standard, and will be very difficult to refute," said Dr. Andy Dobson, an epidemiologist from Princeton University who specializes in wildlife diseases.

The study's implications may be severe for wild salmon. "Even the best case scenario of an additional ten per cent mortality from farm-origin sea lice could push a fish stock into the red zone," said biologist Dr. John Volpe, a study co-author at the University of Victoria.

Although the study was conducted in British Columbia, the results apply globally. "This study really raises the question of whether we can have native salmon and large scale aquaculture ?as it is currently practiced ?in the same place," said Dr. Ransom Myers, a fisheries biologist at Dalhousie University.

"It also raises a more distant specter," said Dobson. "When are we going to see the first human disease caused by aquaculture?"

The research was funded primarily by the National Research Council of Canada and the Natural Sciences and Engineering Research Council of Canada. Further support came from the David Suzuki Foundation, the Canadian Sablefish Association, and the British Columbia Wilderness Tourism Association.

"The analysis in this paper almost certainly underestimates the total mortality of juvenile salmon, " said study co-author Dr. Neil Frazer, a physicist at the University of Hawai'i. "We considered only the direct effects of sea lice on fish survival. We did not include the secondary effects of increased predation on infected fish."

"The debate is over," said study co-author Alexandra Morton, a biologist with the Raincoast Research Society. "This paper brings our understanding of farm-origin sea lice and Pacific wild salmon to the point where w e know there is a clear severe impact."
'"/>

Source:University of Alberta


Related biology news :

1. Salmonella caught red-handed
2. Salmonella bacteria use RNA to assess and adjust magnesium levels
3. Salmon go veggie to save wild fish stocks
4. Salmonella survives better in stomach due to altered DNA
5. Researchers reveal the infectious impact of salmon farms on wild salmon
6. New project aims to make large-scale lobster farms feasible
7. Organic farms produce same yields as conventional farms
8. WCS says avian flu prevention should focus on farms, markets
9. From hot springs to rice farms, scientists reveal new insights into the secret lives of archaea
10. Agilent Technologies introduces advanced zebrafish, mouse microarrays for stem cell and developmental biology research
11. Sudden change in social status triggers genetic response in male fish, study finds

Post Your Comments:
*Name:
*Comment:
*Email:


(Date:3/17/2016)... ABI Research, the leader in transformative ... market will reach more than $30 billion by ... Consumer electronics, particularly smartphones, continue to boost the ... reach two billion shipments by 2021 at a ... Research Analyst at ABI Research. "Surveillance is also ...
(Date:3/14/2016)... , Allemagne, March 14, 2016 ... ) - --> - Renvoi : image ... --> --> ... biométriques, fournit de nouveaux lecteurs d,empreintes digitales pour ... de DERMALOG sera utilisé pour produire des cartes ...
(Date:3/10/2016)... , March 10, 2016   Unisys Corporation (NYSE: ... Border Protection (CBP) is testing its biometric identity solution ... Diego to help identify certain non-U.S. citizens leaving ... The test, designed to help determine the efficiency and accuracy ... in February and will run until May 2016. --> ...
Breaking Biology News(10 mins):
(Date:4/26/2016)... ... April 26, 2016 , ... ... that Ardy Arianpour has joined the company as Chief Business Officer. Arianpour, a ... innovative genomic technologies to market, was most recently Chief Commercial Officer of Pathway ...
(Date:4/26/2016)... ... April 26, 2016 , ... Heidelberg ... the latest technology innovation for its Volume Pattern Generator (VPG) line of lithography ... of advanced photomasks as well as a solution for mid volume direct write ...
(Date:4/26/2016)... ... April 26, 2016 , ... This unique "Fertility Happy Hour" event will be ... opportunity to get the lowdown on female fertility and the reproductive technologies that are ... Hade, of Boston IVF - The Arizona Center, will give a short presentation and ...
(Date:4/26/2016)... ... April 26, 2016 , ... Seattle ... significant operating grant from 1Plus12 Corporation. The grant will be used to further ... outlined on the organization's website http://www.ivsci.org , In accounting the grant ...
Breaking Biology Technology: