A DFO-funded study by UBC rsearchers into prey availability for southern resident killer whales (SRKW) has made some interesting observations. Basically, there’s no lack of chinook salmon as a food source where the SRKWs normally range. The article, published in the Canadian Journal of Fisheries and Acquatic Sciences, may be read here wth the title, “Southern resident killer whales encounter higher prey densities than northern resident killer whales during summer”.
Contrary to expectations, we found the density of potential prey available to southern resident killer whales was relatively high during summer in the coastal waters of British Columbia and Washington, where salmon restoration and enhancement management efforts including the commercial and recreational fishing regulations have been focused. “Southern resident killer whales encounter higher prey densities than northern resident killer whales during summer”
As this study using acoustic technqiues – ship based echosounders – had very few similar studies with which to compare data, and none in the same regions and for the same fish species; and it focused on specific times and places – there are limits to what may be concluded.
The study does, however, suggest that the closures and non-retention restrictions imposed by DFO upon southern Vancouver Island recreational fishers during peak chinook migration over the past few years has been all pain and no gain. And this year, of course, the commercial chinook fishery was pretty much shut down with next to no notice.
Going forward, please let’s not confuse the precautionary principle with the politically inspired rewriting of the rules.