There’s a story running on the CBC website today:
I had to leave a comment on the story as the article suggests:
After a series of lean seasons in which sockeye runs were paltry on B.C.’s southwest coast, at least seven million and as many as 11 million of the highly prized salmon are expected to return to spawning grounds this year.
As I mentioned in my comment on the story: No, there will not be 7 – 11 million sockeye reaching the “spawning grounds” this year. Those numbers are pre-season forecasts of total run size. Before reaching their spawning grounds those sockeye need to run the gauntlet of killers including: sticky trigger fingers at DFO to open commercial and sport fisheries, predators such as seals and orcas and bears, First Nation fisheries, and the deadliest killer of all HOT water.
The Fraser is running temperatures well above avg and now approaching 20 degrees C. It is also running between 20-25% below average water levels. Less water generally means easier to heat. I wouldn’t want to know the temperatures in the Thompson River right now after weeks of stinking hot weather.
When B.C. is burning and there are air quality warnings up around the Province due to smoke from fires… that probably means the rivers are running a little warm…
As I mention in my comment to the article, we’ll be lucky to see even 3 million sockeye actually reach their “spawning grounds”, some of which are over a thousand kilometres from the Fraser estuary and Salish Sea (Georgia Strait) where commercial fisheries are hammering on Fraser sockeye right now.
Remember this graph?
From the Simon Fraser University convened “Salmon Think Tank” in late 2009:
See that average productivity of less than 2 adults returning per spawner. By my rough math… if we’ll be lucky to see 3 million Fraser sockeye spawners this year, and average productivity is 2 returning adults (of which you can see that the big red dot of 2009 is significantly less than 2). That equals about 6 million returning adults in four years.
My rough math suggests 7 to 11 million pre-season forecast this year, lucky to get 3 million to the spawning grounds – that’s an average of about 43% to 27% of total run actually reaching the grounds (which is prob. pretty optimistic). In four years, a total run of 6 million, and we’d be looking at 6 million x 43% = 2.6 million on the grounds OR 6 million x 27% = 1.62 million.
So then we could be looking at between 1.62 million to 2.6 million spawners, giving a total run size in four years of…
I think you get the picture, it’s a downward death spiral.
It’s not that I want to be a pessimist about productivity returning to Fraser River sockeye… it’s simply that if the decline is as dramatic as the graph above suggests, then shouldn’t we be WAYYY more precautionary in opening up fisheries?
Shouldn’t as many Fraser sockeye as possible reach the spawning grounds?
Don’t buy the good old “over-escapement” story, you know, the too many sockeye on the spawning grounds spoils the broth…
Estimates suggest in the 1800s almost 160 million sockeye alone returned to the Fraser River. Yeah, that’s 160 million… and this year we’re talking 7 – 11 million total run size forecast.