3-Minute Market Insight – What Happened to the Fraser River Sockeye Salmon? We ask DFO, Scientist and Fishermen

This is Robert Reierson and here is the Seafood News for the week of October 3rd 2016
— For this special 300th episode we dug deep to find answers for the question in the back of everyone’s mind – where has all the Fraser River Sockeye salmon gone?
In the final in-season assessment of the Fraser River, the Pacific Salmon Commission reported parts of the Fraser at 2.5 degrees higher than average for this time of year, as well as 15 percent lower water discharge.
We spoke with Angela Bates, the Area Director for Fraser and BC Interior at the Department of Fisheries and Oceans in Vancouver, to investigate recent spawning trends.
We Asked: The lowest return on record since 1893 is expected this year – what are the factors?
Angela: “one thing that I should note is that although this is the lowest return on record, it may not be the lowest spawning on record, so we are still waiting to see what happens with respect to fish that actually came back from spawning grounds”
Angela: “So far we’ve actually seen that fish that are coming back are in pretty good condition, and the environmental conditions in the river this year were better than some previous years so we’re optimistic that we’ll get a good spawn.”
A big challenge with Sockeye is the dynamic outlook for this fishery, which Angela attributed to habitat availability, ocean conditions, and difficulty monitoring stocks.
We Asked: Fishery estimates are ever-changing, why is this fishery so difficult to monitor?
Angela: “So we can see how many fish come back and spawn, but it is difficult to know what happens to them when they are in the ocean. And once they go out to sea we have some ability to do some tracking where we, for hatchery fish for example where we can mark them and track them a little bit, but really the big thing is that we can’t see them in the ocean, so unlike land based animals where you could go into the field and kind of count and see what’s happening, fish you can’t do that in. So that’s a challenge of any aquatic species really.”
Angela indicated it’s not all doom and gloom, parts of the Columbia system and Barkley Sound saw good returns this year, a comment that was paralleled by many fishermen we spoke to.
So why are Sockeye stocks doing poorly when other stocks are successful?
— Kyla went in the field yesterday to discuss this question with a local molecular geneticist at DFO.
We asked: Why are Fraser River Sockeye so unpredictable?
Kristi: “The interesting thing is that Fraser River Sockeye are not the only species that are in decline in returning abundance and overall productivity. Chinook and Coho also have a lot of stocks that are in decline. But interestingly, even though the sockeye salmon is probably the most managed species, it has been the hardest to predict annual variation. One of the potential reasons could be that the management models that are used to predict returns are simply not working under the climate conditions that we have today. And a lot of those models go back and look at returns forecast over 30 and 40 years, and use that information in the predictions for upcoming years and they don’t necessarily include all the environmental variables that could be undermining performance in the marine environments, especially as climates changing. So that’s something that a lot of people are looking at now.”
We Asked: Are current conditions along the Fraser Cyclical or Detrimental in the long term?
Kristi: “Well we do know that high water temperatures and low discharge can increase mortality in return migrating fish to a huge degree, we know a whole lot less about their impacts on juvenile stages. I’ve worked a lot with a team at UBC from Scott Hinge’s group there and have graduate students that have done a lot of work looking at the impact of increased temperature on stress and survival on salmon. And we’re also now looking at the impact of high water temperatures on disease development. And we know from the studies that we performed that water temperatures have a huge impact on salmon in the Fraser River. All of the work again has been on adult salmon, we’re now refocusing our efforts on juvenile stages.”
— We are headquarted on the West Coast of B.C. so Kyla was also able to speak with Jeffery Young, a Senior Science and Policy Analyst for the David Suzuki Foundation, about environmental factors in more depth.
Jeffery alluded to the warm “blob” that travelled the West Coast this summer as a significant factor of low run estimates, but that larger environmental factors are at play.
We asked: How has climate change affected Fraser River Sockeye stocks?
Jeffery: “The other key factor that’s related to climate change is increased temperatures in freshwater in the Fraser River itself as well as some of the streams that these fish would be spawning in. That’s been on a fairly steady rise over the past few decades, and it’s a real indicator that we’ve got some steady climate change effects in freshwater at least. Sockeye salmon are near the southern extent of their range, as a result they’ve always been somewhat temperature sensitive and kind of at their lower limit in terms of what they can handle. And with these increased temperatures we’re getting much higher mortality in river and bigger risks from disease.”
Several Fraser River fishermen we spoke to indicated that aquaculture plays a big role in the area, a topic which DFO is still doing research on, but Jeffery was able to comment on.
We asked: Has aquaculture contributed to recent trends for Fraser River Sockeye?
Jeffery: “We know that juvenile sockeye salmon migrate past a number of open net cage salmon farms, particularly in the Discovery Islands. We also know that parasite loads on those fish are higher in some years at least, related to salmon farms, and that they can also transmit disease. Higher temperatures from recent ocean conditions actually exacerbate the impacts both of parasites and the prevalence of disease so it’s plausible that some of these open net cage salmon farms have had some impacts during the most vulnerable life phase of salmon, which is the juvenile phase when they’d be migrating past those farms. So the biggest concerns from aquaculture that we continue to have for Fraser River sockeye salmon are disease and parasite impacts, that are exacerbated by warmer ocean conditions.”
Jeffery noted that as fresh water detriments steadily increase, there are unprecedented conditions to indicate the Fraser is on a steady track to worsening.
Chinook are also struggling, indicative of poor sockeye runs in the future as they spend less time in the ocean, so what is the outlook for the future?
We asked: What is your crystal ball outlook for the short term future of this Fishery?
Jeffery: “By 2018 when we expect the next big return, we should see more fish than we saw this year, we should see in the millions which is normal. What we don’t know is if it will be similar to some of the record high returns from 2010 or whether it will still be depressed rather than that average. It’s very likely that there will be some sort of sockeye fishing in 2018, it’s very likely that next year will be quite poor. Beyond that, these ongoing concerns with freshwater temperatures as a result of climate change and the potential for climate change to further allow this warm ocean “blob” to continue and to ultimately get worse over time is something we don’t know how it will effect year-by-year but ultimately could get worse with longer periods of time.”
— Analyzing all of these perspectives and scientific research we can see that successful spawning could bring Sockeye back to the area but climate change will ultimately challenge this fishery in the long term.
As a staple on the West Coast to many industries, families, and local businesses, we all continue to follow this fishery closely.
— Thank you for joining me for the Tradex Foods 3-Minute Market Insight. This is Robert Reierson, buy smart and eat more seafood.