What’s so special about Harrison River sockeye salmon?

2012_Harrison_sockeye_escapement
While most Fraser River sockeye salmon stocks have generally declined in the last decade, the Harrison River stock have managed to increase their productivity.
Total Fraser River sockeye returns and productivity since detailed records began in the 1950s.
Total Fraser River sockeye returns and productivity since detailed records began in the 1950s.

Why has one group of sockeye salmon from the Fraser River system experienced a growth in productivity over the past decade while other Fraser River stocks have declined?

Storytellers playing scientist have tried to convince people Harrison River sockeye don`t pass salmon farms when they migrate north, therefore they are doing well simply because they don’t pass salmon farms. This explains everything if you’re already predisposed to blame salmon farms for everything and accept simple answers to tough questions.

It’s true that at least some Harrison sockeye migrate out of the river delta and go along the West Coast of Vancouver Island, unlike most other stocks which generally migrate along the East Coast of Vancouver Island.

However, as usual with activism-driven science claims, there`s a lot more to the story.

For one thing, it’s not true that Harrison sockeye going through Juan de Fuca Strait don’t pass salmon farms.

But the most important piece of the puzzle is that Harrison sockeye have a very different life strategy than other salmon stocks.

Unlike other sockeye, which feed and grow in lakes for several years before going to sea, Harrison sockeye go to sea shortly after they emerge from the gravel where they hatched. They are in the ocean nearly a year earlier than other sockeye stocks. This may give them an advantage in early marine survival growth, occupying a niche that few other species do. They may enjoy better feeding conditions as fry and juveniles, less competition for food and less threats from predators.

It also appears some winter off the West Coast of Vancouver Island in their first year.

Harrison River sockeye have been found to winter on the West Coast of Vancouver Island (black triangles note location where they were found) while they are still juveniles. They appear to be co-existing very well with the approximately 30 salmon farms from Quatsino Sound south to Alberni Inlet.
Harrison River sockeye have been found to winter on the West Coast of Vancouver Island (black triangles note location where they were found) while they are still juveniles. They appear to be co-existing very well with the approximately 30 salmon farms from Quatsino Sound south to Alberni Inlet.

Let’s say that again. A significant amount of Harrison River sockeye winter off the West Coast of Vancouver Island when they are very small, young and vulnerable.

There are approximately 30 active salmon farms on the West Coast of Vancouver Island, from Quatsino Sound south to Alberni Inlet. Clearly they are not having any negative impacts on wintering Harrison sockeye, not even when they are at a young and vulnerable stage.

The Harrison sockeye appear to have developed a very successful survival strategy, and it appears it co-exists very well with salmon farms. More research is needed to explore this connection.

More resources: This map shows all the registered salmon farm and hatchery tenures in B.C. However, many of the sites on the list have been inactive for years or have been rescinded by the provincial government. Typically, there are about 70 active farms in British Columbia.

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5 thoughts on “What’s so special about Harrison River sockeye salmon?”

  1. Similar to the Harrison stock, the Hayden River sockeye (Lochborough Inlet just NE of Campbell River) also have seen strong returns over past decade or so. They also swim directly to sea after hatching.

    Oh, and the Hayden sockeye swim right past farms.

    Location to salmon farms is a red herring and because of a few idiots (and that’s the kindest term I can think of), they’ve wasted resources on chasing a non-starter. The ‘unique’ lifecycle is the what should be investigated.

  2. I think it is also important when looking at productivity to put this number into context with the changes in the conservation paradigm in DFO. For the past 15 years the escapement numbers as a percent of the returning population have risen dramatically. This change in management means that the apparent productivity is much lower simply because the escape number give more spawning fish relative to number of fish returning.Without taking into consideration the change in management, the general downward trend in productivity is completely misunderstood. It is an artifact of the change in management not a reflection of the well being of the population

    If you look at the total number of fish returning and not the “productivity” you see that there is no real decline in the abundance of FRS over the last 60 years. This point was made at the Cohen Commission hearing but was apparently lost during the writing of the report.

  3. One would think that the less time spent swimming around with the rotting corpses of your preceeding generation the better.

  4. Great information. Although, your statement that Harrison sockeye only migrate via the West side of Vancouver Island, may not be 100% accurate. As the Tucker study states;

    “In winter, catches were low for all stocks of sockeye salmon; however we caught a conspicuous group (n ¼ 47) of sockeye salmon off the west coast of Vancouver Island. These were identified as Harrison River origin individuals from the Fraser River drainage (Figure 6B). In fact, this was the only time of year that Harrison River sockeye salmon were caught; a pattern entirely opposite to other Fraser River origin fish.”

    Yes, a small # of Harrison sockeye were caught heading in that direction, but it doesn’t provide evidence of 100% migration.

    This fact only bolsters your argument that suggests that something other than the direction they swim (like early sea water entry/less time in the Fraser River) is responsible for the better than average returns.

    Well done – one can only hope those that aren’t labotomized are interested in the facts.

    1. Thanks Brent. We weren’t trying to suggest that Harrison sockeye only go along the West Coast of Vancouver Island, they have been caught in other places too. Apologies if that’s how the post reads!

      Also we agree that it’s probably something other than the direction they swim, particularly their early entry and short time in fresh water, that contributes to their good productivity. It seems to work well enough for pinks!

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