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By Carla Booth.  Where  Host and Parasite  Life Cycle  The Study  Results  Conclusions.

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Presentation on theme: "By Carla Booth.  Where  Host and Parasite  Life Cycle  The Study  Results  Conclusions."— Presentation transcript:

1 By Carla Booth

2  Where  Host and Parasite  Life Cycle  The Study  Results  Conclusions

3 Broughton Archipelago http://www.wavelengthmagazine.com/2006/dj06archipelago.html http://www.britishcolumbia.com/regions/towns/?webRegionID=2&townID=4145 http://www.cbc.ca/news/canada/british-columbia/story/2010/04/13/bc- first-nations-fish-farm-lawsuit.html Norway Scotland Ireland Canada

4  Host  Oncorhynchus gorbuscha and Oncorhynchus keta (pink and chum, respectively)  Parasite  Lepeophtheirus salmonis (common name sea lice)

5  Wild Salmon  These Salmon are a keystone species for the ecosystem  Contribute to the ‘counter current exchange pump’  They mate up the streams and rivers then die  Bodies provide nutrients to predators and to the environment when the die  Wild salmon juveniles are not sympatric with adults (and their parasites) until they are mature or for approximately 2.5 months  Farmed Salmon  A single farm can have the equivalent of 360 bull elephants in fish at one farm (~600, 000 fish)  Huge amounts of waste and contaminants (eg. Clams in Broughton Archepelago)  Contaminants such as:  Mercury  Polychlorinated biphenyls (PCBs)  Parasites  When the wild fry swim past the farms they are exposed to parasites from the farmed fish

6  Remember not a louse but a Copepod  Multiple stages (10)  Nauplius  Copepodid  Chalimus  Mobile Stage

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8  Looking at the impact of aquaculture on wild salmon populations  Causal linkage between farmed fish and increasing sea lice obfuscated by:  Density dependent climate  Fishing  Habitat degradation  So they used mathematical models to clarify some of those factors  Estimated scenarios using the models then matched the field results to the parameters of the model  At intervals of 1- to 3-km along the 80 km of migration route fish were sampled  Looked at two things:  Infection dynamic  Survival of infected individuals

9  Captured 100 juvenile salmon (fry) as they approached and passed the salmon farms  Using nonlethal sea lice enumeration technique they counted the number of parasites (various stages)  Taking a sample of infected fry to an ocean enclosure to monitor survival

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11 Results Juvenile Chum Salmon Infection dynamic

12 Results Survivability

13  Infection dynamics  Farm salmon are the primary source of lice above the ambient levels along 80 km of river  As the fry pass the farms they are more likely to be infected; the more farms they pass the more infection  Survivability  Found that 2 or more lice was lethal; less than two had poor survivability  “The High pathogenicity and abundance of lice resulting in farm induced cumulative epizootic mortality ranging from 9%- 95%”

14  Easton, M.D.L., Lasuzniak, D., & E. Von der Geest. 2002. Preliminary examination of contaminant loadings in farmed salmon, wild salmon, and commercial salmon feed. Chemosphere, 1053-1074.  Groom, M.J., Meffe, G.K., & C.R. Carroll. Principles of Conservation Biology, Third Edition. Sutherland: Sinauer Associates Inc.  Krkosek, M., Lewis, M.A., Morton, A., Frazer, N. L., Volpe, J. P., 2006. Epizootics of wild fish induced by farm fish. PNAS, 15506-15510.  Morton, A., Routledge, R., & M. Krkosek. 2008. Sea Louse Infestation in Wild Juvenile Salmon and Pacific Herring Associated with Fish Farms Off the east-central Coast of Vancouver Island, British Columbia. North American Journal of Fisheries Management, 28, 523-532.  Selbie, D.T., Lewis, Smol, J.P., & B.P. Finney. 2007. Long-term population dynamics of the endangered Snake River sockeye salmon: Evidence of past influences on stock decline and impediments to recovery. Transactions of the American Fisheries Society, 136(3), 800-821.

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