Agreeing to disagree: A fish story by any other name
By Anthony Farrell, Vancouver Sun August 27, 2011
Scientists routinely agree to disagree, but that doesn't sit well with society-at-large, which increasingly demands instant answers and quick solutions.
Nowhere is this more painfully apparent than in the debate and confusion around the future of salmon in British Columbia, which is the current topic of an expensive federal inquiry, the Cohen Commission.
The problem is that we expect too much, too soon from science. The announcement of an "overnight" discovery is always backed by an awful lot of scientific discovery and testing.
While responsible scientists couch their discoveries with words like could, may and might, prudent caution too often gets lost in translation.
Take my salmon research in B.C. as an example.
A news headline early this year claimed a virus from farmed salmon is killing wild sockeye salmon in the Fraser River.
As a co-author of the research cited as the headline's source, which appeared in the prestigious scientific journal Science, I can safely say our position was far more circumspect. Yet, somehow the headline stretched a discovery-phase hypothesis on a genomic expression signature associated with sockeye salmon to claim a virus had come from farmed salmon! Clearly,
this is an illustration of the knowledge gap between science and public perception.
Proclaiming certainty takes time and many experiments, but here's another example of how a hypothesis - not a certainty - concerning wild salmon was debated and subsequently revised with new information: In an article in Science in 2007, results of a mathematical model were used to boldly declare: "If outbreaks [of sea lice] continue, local extinction [of pink salmon] is certain" in the Broughton Archipelago.
This terrific sound bite triggered a media blitz promoting the idea that sea lice released from Atlantic salmon farming were decimating wild pink salmon populations.
Fast forward to 2011. Did these wild pink salmon populations collapse? No. Either something changed dramatically or the study's conclusions were premature. Here's the lesson: In the discovery phase, the devil lies in the details.
In fact, juvenile pink salmon are a lot tougher than we initially thought when it comes to sea lice infestations.
There is little to suggest sea lice would kill 80 per cent of infected pink salmon, as the original model posited.
In fact, a 2010 report - Relationship of Farm Salmon, Sea Lice and Wild Salmon, published in another prestigious scientific journal, Proceedings of the National Academy of Science - concludes: "Productivity of wild salmon is not negatively associated with either farm lice numbers or farm fish production, and all published field and laboratory data support the conclusion that something other than sea lice caused the population decline [of pink salmon] in 2002."
Clearly, profound differences of opinion exist among scientists during this initial discovery phase. And that's normal.
Inasmuch as we must maintain vigilance, uncertainty cannot paralyze progress.
Consider the projections of a dismal sockeye salmon return to the Fraser River in 2009. According to some mathematical models, there was a one-in-500 chance of it happening.
But scientific probability models didn't sit well with an outraged public, which demanded investigation and got a public inquiry in the form of the ongoing Cohen Commission, which is costing tens of millions of federal dollars that I suggest might be better spent on scientific investigation into the many mysteries of salmon.
Of course, smiles quickly returned with the near historic return of sockeye last fall.
This return had a one-in-10 probability of happening according to scientific models. Scientists are doing their best with limited resources and discovery science remains far from a sure bet.
Yet, the public, which is clearly selective in its risk tolerance, demands absolutes from the media when confronted with questions about natural phenomena like salmon.
As Malcolm Gladwell writes in What the Dog Saw: "Rarely is there a clear story - at least, not until afterward, when some enterprising journalists or investigative committee decides to write one."
Have your headlines if you must, because in this fast-paced world we can't always wait for hindsight, but can we agree to not represent hypotheses - no matter how intriguing - as facts?
Dr. Anthony Farrell holds a Canada research chair in fish physiology, culture and conservation as a professor at the University of British Columbia, with a cross appointment in the zoology department and the faculty of land and food systems.
