SFU centre bridges troubled waters

Mar 20, 2003, vol. 26, no. 6
By Carol Thorbes

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The fate of millions of juvenile pink salmon has Simon Fraser University's centre for coastal studies (CCS) navigating troubled waters again.

Since its inception two years ago, the centre has helped often-conflicting groups come together to discuss and resolve controversial issues related to fishing, aquaculture, and ecological management.

This time the CCS is applying its mediation and research expertise to helping government, industry, community representatives and researchers understand a potential sea lice problem in B.C.

SFU statistics professor Rick Routledge, (above) a CCS member, is helping biologist Alexandra Morton estimate sea lice infestation of wild juvenile salmon in the Broughton Archipelago for the second consecutive year.
A sudden decline in wild pink salmon in the salmon farm-laden region off B.C.'s south central coast sparked their concern.

Their analysis set off more alarm bells.

Sea lice may attach to the gills and head regions of fish, often causing bleeding, increased stress and possibly death.

“Juveniles, especially pink salmon, face certain death due to their tiny size and developing systems, if infected with only a few lice,” says Craig Orr, CCS associate director.

Last year, the federal department of fisheries had expected three to four million pink salmon to return to spawning grounds in the streams that feed mainland inlets near the archipelago. Only 170 thousand came back.

Upon analysing salmon migration figures in the area last year, Routledge and Morton found that juvenile pink salmon had an average of less than one louse per fish. That was before they passed by the archipelago's 27 salmon farms (11 were fallow).

Another check, after passing the farms, estimated the average infestation rate at more than six per fish.

Routledge and two graduate students also checked the sea lice infestation level in juvenile wild pink salmon taken from nearby Rivers and Smith Inlets, which do not have salmon farms. The infestation was negligible.

“These figures indicate that there was an outbreak of sea lice around the fish farms in the Broughton Archipelago with the obvious candidate source being the fish farms,” says Routledge. “The evidence is indirect, but surely this warrants immediate public disclosure of the fish farms' records of lice loads on their fish - and the development of thorough government auditing procedures to ensure the accuracy of such records.”

This spring, the fish population estimation expert is helping federal fisheries scientists, as well as Morton, study the archipelago's lice infestation rate of juvenile wild pinks.

SFU has now hosted three workshops on the potential problems of sea lice infestations.

“Studies in Norway, Ireland and Scotland show that, whereever you have salmon farming, you have declines in wild salmonid populations,” says Orr, a SFU ecology grad and director of Watershed Watch, a science-based salmon conservation group.

He notes studies indicate sea lice infestations hurt salmon farmers too, citing a study in which New Brunswick salmon farmers lost $350,000 annually per farm in treatment costs and lost production.

Orr underscores, “We need to know the population dynamics of sea lice, what their naturally occurring numbers are compared to their numbers in fish farms, and the costs and efficacy of chemical treatments. That's just a start.”

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