Fraser River sockeye salmon: data synthesis and cumulative impacts

Comments are welcomed on the indicators and their potential influence on sockeye habitat useand potential risk of loss or degradation of key sockeye habitats from 1990 to 2010.DiscussionMcKinnell: When was Roberts Bank built?Johannes: In the 1980s? It’s important mostly for sediment as you don’t catch sockeye smoltsthere, only pink and chum.McKinnell: I wonder if increased light pollution in Georgia Strait makes sockeye smolts morevulnerable to predation?Johannes: We don’t know. The Fraser plume is dynamic and while there is only one study onthis, I can’t imagine sockeye not using the plume wherever possible. They use favourablecurrents in Georgia Strait to move quickly. If they are in good condition, they will stop tofeed, but if conditions are bad they will move fast. Re light pollution, they will shy awaypretty quickly.Dorner: Are there any thoughts on cruise ship discharges and Heterosigma blooms?Johannes: We only have Port of Vancouver data for ballast discharge. I suspect the amountspales compared to resident discharges. Heterosigma may be part of a “death by a thousandknives” pattern.Ashley: Transport Canada regulations specify conditions for ship discharges. I will send you areport that collected data on cruise ships.English: This is a very broad topic. I would encourage you to focus on the specific locations andtimes when sockeye are in specific areas. For example, what are the river discharges like atthe time when juvenile sockeye are migrating out. There is limited data, but there is somefrom recent tagging and also smolt timing at the Chilko fence, and then compare that to algaeblooms, river flow, temperature, etc.Johannes: I’ve taken every observation I can find and put it in the database so we will have timeplaceassociation. There is anecdotal information but not good data on when the bulk ofsockeye smolts are moving through the Lower Fraser. But we will try to do the associationwith algae blooms, etc.Rosenau: Do you have enough data to say where sockeye are distributed in Georgia Strait. Is itjust the shorelines?Johannes: They use the (upper limnetic?) habitats, not the littoral zone and they use the shelfrather that the deep troughs. I will try to catalogue whatever information exists on whichenvironment sockeye are using, but the issue is that it can change from year to year.Rosenau: Where are boundaries of the study? Do you go up to Campbell River or does it stopearlier. It’s very different from Campbell River to northern Vancouver Island, and this relatesto fish farms and massive anthropogenic effects. This may be covered by other groups but weshould look at habitat for the greater Georgia basinJohannes: I can comment in my report but I understand that other groups are investigating it. Thenorthern boundary is Quadra/Cortes and I will use whatever information I have. Sockeyemove around a lot and how do these changes affect survival. The best data I have are herring60