M. Scott Taylor of the University of Calgary has recently published his research on international commercial shipping traffic off the B.C. coast and its impact on the southern resident killer whales.
The whale population has decreased by more than 25% in the past two decades and Taylor took on the task of finding out why. It’s a sobering study, which supports a conclusion that the whales are on a slow-motion decline to extinction.
I have been fortunate to see the whales on several occasions and they were a magnificent and beautiful sight. The disappearance of this significant tourist attraction and cultural icon for much of the Pacific Northwest would be, to me and many others, an exceedingly tragic loss.
Taylor began his study by calculating the kilometres travelled by noise generated by commercial vessels in the critical habitat of the killer whales. He further refined his calculations to derive potential measures of vessel disturbances by month, year, location and vessel type.
Next, he attempted to create a rationale for the divergent behaviour of the killer whales and their northern counterparts, which are healthier and indeed expanding in size.
He found an exceedingly simple explanation. An increase in vessel traffic in the critical habitat of southern resident killer whales lowers their hunting productivity and directly weakens their ability to compete for prey they share with the northern killer whales.
Such negative shocks occur mainly in the south, but also have a smaller impact in the north. This unequal impact is magnified by cross-population competition for prey and, if the impact is large and asymmetric, it will, of itself, lead to the extinction of the southern whales.
Taylor then applies empirical testing of this idea to the impact of engine noise shocks on both of the pods of whales.
He also finds a consistently positive impact of salmon availability to whale fecundity and mortality. He then finds that a three-standard-deviation-sized increase in the salmon stock above its historic mean would offset the negative impact of vessel disturbance but, of course, such an outsized increase is virtually impossible.
The salmon stocks could be increased by severely limiting sport fishing — if not shutting it off completely — and greatly reducing or banning commercial fishing. These extreme policy options, however, are not guaranteed to achieve good results, particularly as the problem involves ocean-going traffic that is increasing year by year.
A way to protect the whales is not obvious from this study. So, Taylor sees no likely alternative to their gradual extinction.
What is needed is a dialogue about his findings and the types of policies that must be implemented now to slow the rate of attrition.
It will require both the U.S. and Canada, together with stakeholders in commercial and sports fishing, whale watching and container shipping companies, to come together and formulate a sophisticated multifaceted longer-term plan with benchmark evaluations to measure its success.
Canada has already suffered a disaster to its fishing resources on the east coast with the collapse of the cod fishery. That was in large measure occasioned by the unwillingness of politicians to adopt needed policies until they had no options left because the fish were essentially gone.
Let us hope, indeed demand, that such a failure to intervene not snuff out the killer whales and the salmon stocks.
David Bond is a retired bank economist who lives in Kelowna.