Opinion: Looking into the crystal ball for Fraser River sockeye returns
Predictions don’t always come to pass
By Donald Noakes, Special to the Vancouver Sun July 31, 2014
The return of the salmon to river mouths along B.C.’s coast is a summer tradition in British Columbia that dates back centuries. Every year we witness the return of Fraser River sockeye, whose parents fought their way back upstream four years previously, the highlight in October being the world renowned Adams River run.
Each spring, well before migrating salmon reach the top end of Vancouver Island on their way back to their natal streams, salmon prognosticators look into their crystal ball, crunch the numbers, then release to the public the number of salmon they expect will to return from their ocean adventure.
They have created a new level of excitement this year, forecasting the river will teem with a record or near record number of sockeye, great news for all involved, especially those who make their living harvesting and selling salmon.
But should we be excited for the salmon to come, or cautiously hopeful the tea leaves tell the story we want to hear? Nature is a funny thing. No matter how you look at the numbers, you rarely get what you expect.
This year marks the return of sockeye produced by the record setting 2010 run of more than 28 million salmon, a number that was well beyond expectations and now setting the excitement of another record bounty.
The prediction is for 23 million sockeye to return to the Fraser in 2014, with a 10-per-cent chance the run will be less than 7.2 million or greater than 72 million fish. While most people would believe 23 million is a reasonable forecast, remember the 2010 forecast for Fraser sockeye was well below the actual return and the much lower-than-expected 2009 run led to the $26 million Cohen Commission, even though the sockeye returns for both years were within the predicted ranges.
Clearly, too much focus is put on the number and not enough attention is paid to the full message with respect to forecast returns.
This broad range (7.2 to 72 million) reflects the uncertainty in forecasting salmon returns despite decades of monitoring and research. Notwithstanding their inherent lack of accuracy and precision, too often when returns are less than the pre-season prediction (often the result of natural and uncontrollable fluctuations or changes in ocean conditions or climate) there has been a tendency to concentrate on “missing” salmon that existed only on paper.
There have been three inquiries (including the Cohen Commission) into missing salmon that have resulted in significant changes and improvements in the management and conservation of salmon stocks, although some would argue more dramatic changes are needed and justified. The reality is that managing salmon resources is extremely complex, and in British Columbia salmon fisheries and stocks are managed as well as, or better, than anywhere in the world.
Salmon returns in Alaska and to other rivers along the west coast have to date generally been strong (albeit with many fish being smaller than average in size) supporting the expectation of a better-than-average sockeye return to the Fraser. This is welcome news for a fishery that has experienced a number of conservation-related closures in recent years.
However, nothing is certain when it comes to Pacific salmon and strong returns of salmon to one system or region do not guarantee strong returns to another, including the Fraser. While some would view a return of less than 23 million as disappointing, it would by no means be a disaster nor would or should it be viewed as entirely unexpected.
Although salmon management has become much more conservative since the early 1990s, there has been little improvement in the accuracy or precision of pre-season forecasts of run strength. Fortunately, improvements to in-season management have reduced, but not entirely eliminated, risks to our salmon stocks.
While the outlook for 2014 Fraser River sockeye is positive, success will be measured in the ability to balance responsible resource use and conservation. Let’s hope the forecasts for another record return come true but also remember to temper your expectations.
Donald Noakes is former director of the Pacific Biological Station and head of aquaculture for Fisheries and Oceans Canada, current chair of the mathematics and statistics department and incoming dean, faculty of science and technology at Vancouver Island University.
