Fraser River sockeye salmon: data synthesis and cumulative impacts

temperatures. Notably, it doesn’t seem to have affected the West coast sockeye salmonstocks that, presumably, were migrating along the West coast that year.English: The PSC report discussed harmful algae blooms. Could you have had that in QueenCharlotte Sound?McKinnell: Or parasites. There were very high temperatures, but there is no algae bloommonitoring. Heterosigma has appeared in Georgia Strait in years of higher riverdischarge. There was a persistent Heterosigma bloom in Georgia Strait in July andAugust that year.English: I saw an extensive bloom of some kind in Queen Charlotte Strait while sailingthrough the area that year.Marmorek: Page 74 of the PSC report talks about the Georgia Strait and Queen CharlotteSound algae bloom.McKinnell: We looked at bottom-up effects of phytoplankton/chlorophyll, not harmfulblooms. I can imagine that there could have been a combination of undesirable trophicconditions, plus a bloom. But I keep coming back to why the survival of 2-year oldChilko smolts was so much higher than that of the 1-year olds if they both encountered aHeterosigma bloom.English: It could be timing.Christensen: It’s a compelling story, but if this was a prosecutor, his case would be breakingdown and we are still trying to find proof of guilt.McKinnell: No one found dead sockeye at sea to provide firm proof. But we have observedan extreme effect in biology and we are looking to see whether there are equivalentextremes in oceanography. We find that those are far more evident in Queen CharlotteSound/Strait rather than Georgia Strait.Marmorek: The prosecutor may not be the best analogy for what we’re doing. We’re looking atwhat is the relative likelihood of different theories, which may not be mutually exclusive andmay be collaborating. For example, contaminants don’t seem likely. Which factor orcombination of factors explains the pattern that Peterman and Dorner outlined? Did the PSCget it right or does new evidence point elsewhere. We’re looking at conceptual models andhow factors may be interacting. The idea of an attack from the land is a new idea.Peterman: Did you find the same pattern as we did in terms of a shared trend for stocks outsidethe Fraser?Day 2McKinnell: Yes, the spatial scale of the effect is bigger than Georgia Strait.Introductory remarks, plan for Day 2Dave Marmorek, ESSAMarmorek welcomed everyone and reviewed the day’s agenda.53