SHARKS IN BC?

May 09, 2011

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Mark Hume, at the Globe & Mail, just published a neat new story about our recently published paper on sharks in BC (with Tom Okey, Scott Wallace and Vince Gallucci).  The paper was published months ago, but became newsworthy again recently in light of the Cohen Commission’s discussions about the potential role of marine predators in governing salmon population dynamics in BC.  Over and over again at that hearing, we heard that scientists, managers and decision-makers in BC need good estimates of abundance for top predators in our marine ecosystem.

Our shark survey, which we conducted with Raincoast Conservation, was originally designed to estimate abundance and distribution of cetaceans (whales, dolphins and porpoises) in BC, because that number wasn’t available at the time for species that can’t be studied using photo-identification.  Thanks to an incredibly hard-working team with strong stomachs (we crossed Hecate Strait dozens of times on a relatively small sailboat), we accomplished our primary goal and achieved a number of secondary objectives.  The shark study was a great bonus, but so was our estimate of how much plastic pollution there is in BC waters.  [There is a story on our garbage sightings here, but the peer-reviewed article is coming out in Marine Pollution Bulletin soon.]  We used the data to evaluate where fin, humpback and killer whales are most vulnerable to ship strike risk.  Don’t tell anyone, but we’re also working on a paper on Mola mola (those weird, giant ocean sunfish) in our spare time with sunfish expert, Dr Tierney Thys.  At the same time, we collected zooplankton data, physical oceanographic data (temperature, salinity), and had a seabird observer on board.  We are dying to find the funds to hire a statistician to turn those bird sightings into abundance estimates for seabirds, but that’s a bit of an aside.

Our surveys were conducted initially in 2004, and it’s getting time to start thinking about redoing them.  The thought of all that fundraising and planning is a bit overwhelming, but when we look back at the scientific return on investment, it looks those surveys represented pretty good value.  And who could have anticipated that (a) we’d find massive numbers of sharks; (b) that the salmon people hadn’t considered those predators in their ecosystem models, and (c) that there would be catastrophic sockeye salmon runs in the Fraser River years later that would require us to re-think marine ecosystem functioning in a holistic manner?  Initially, we conducted the surveys out of concern that Canada would lift a moratorium on offshore oil and gas exploration and extraction, and we wanted to be able to quantify the risk to the marine mammals that we study.  That threat has subsided, it seems.  We hope that the next use of our science is in the Pacific North Coast Integrated Management Area planning process.

I guess one lesson here is that basic science never goes out of style.  The other is, as Mark says, if we’re going to continue our work on a bigger scale, we’re gonna need a bigger boat.  [Well, you knew we had to get the Jaws quote in there, right?]

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