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:

(Date:11/12/2015)... , Nov. 12, 2015  A golden retriever ... Duchenne muscular dystrophy (DMD) has provided a new lead ... Children,s Hospital, the Broad Institute of MIT and Harvard ... Brazil . Cell, pinpoints ... dogs "escape" the disease,s effects. The Boston Children,s lab ...
(Date:11/11/2015)... 11, 2015   MedNet Solutions , an innovative SaaS-based ... research, is pleased to announce that it will be a ... event, to be held November 17-19 in ... live demonstrations of iMedNet , MedNet,s easy-to-use, ... iMedNet has been able to deliver time and cost ...
(Date:11/9/2015)... Nov. 09, 2015 ... of the "Global Law Enforcement Biometrics ... --> ) has announced ... Enforcement Biometrics Market 2015-2019" report to ... Markets ( ) has announced the ...
Breaking Biology News(10 mins):
(Date:11/25/2015)... and HOLLISTON, Mass. , ... Inc. (Nasdaq: HART ), a biotechnology company developing ... CEO Jim McGorry will present at the ... 1, 2015 at 2:30 p.m. PT. The presentation will ... for 30 days. Management will also be available at ...
(Date:11/25/2015)... ... November 25, 2015 , ... A long-standing partnership between ... (OPBAP) has been formalized with the signing of a Memorandum of Understanding. , ... leaders Capt. Karl Minter and Capt. Albert Glenn Tuesday, November 24, 2015, at ...
(Date:11/25/2015)... San Francisco, CA (PRWEB) , ... November 25, ... ... leading microbial genomics company uBiome, were featured on AngelList early in their initial ... by launching an AngelList syndicate for individuals looking to make early stage investments ...
(Date:11/24/2015)... 24, 2015 Cepheid (NASDAQ: CPHD ) ... the following conference, and invited investors to participate via ...      Tuesday, December 1, 2015 at 11.00 a.m. Eastern ...      Tuesday, December 1, 2015 at 11.00 a.m. Eastern ... New York, NY      Tuesday, December 1, ...
Breaking Biology Technology: