This post by Jay Nicholas is a response to the recent, thought provoking post on the dilemma faced by those of us who live to fish for wild chinook salmon on the Oregon Coast each fall:
You may recall Oregon’s chinook boom in the late eighties. I know you remember 2002, 2003, and 2004. Those were big run-years, and we all felt like fly fishing heroes. In contrast, the last three years have almost brought us to our knees. Of course, it’s the fish that have really suffered. Most California and Oregon rivers have recently seen the lowest chinook returns in six decades.
How is it that this could have happened? Can we blame the seals? Nope. The bad-boys fishing off Canada and Alaska? Probably not. Foreign fishing factories? Don’t think so. Degraded freshwater conditions in spawning or rearing areas? Doubt it. All of these factors could be taking a little whack at our coastal chinook, but I don’t think, even collectively, they are the principle cause of our depressed runs.
Enter that mysterious and hard to describe “ocean conditions” factor.
Although this villain may seem like a fish biologist’s dream excuse, it is the most likely explanation for the collapse of chinook populations from Sacramento clear up the Oregon Coast during the last several years.
So just what are ocean conditions? While I am not the expert here, I know they include water temperatures, upwelling, primary production at the bottom of the food chain, predators, actual salmon feed, and perhaps even the ominous “dead zones” that we’ve all read about in recent years.
Salmon are best suited to relatively cool water temperatures, so warmer-than-usual water is not good. It elevates metabolic rates into the not-so-good range for salmon. If this gets bad enough, salmon can experience direct mortality of adults, a phenomenon rarely seen except in severe El Nino conditions.
Upwelling is generally good, because it brings cool, nutrient rich water from deep layers to the surface, jump-starting primary production that provides for everyone in the food chain. Upwelling can be not-so-good if it brings up warm water, or cool, nutrient-poor waters.
Upwelling can also be a problem if it brings up a ton of nutrients, which creates a huge primary production bloom, and then dies. If a pile of bottom-of-the-food-chain critters is suddenly swimming in a nutrient poor environment, it can result in a sea of dead little critters that decay and suck all the oxygen from the water, creating “dead zones”. These anoxic areas cannot be good for salmon, but I do not think we completely understand whether or not the salmon can escape these zones.
Predators just need to make a living, like any other critters. If ocean waters are warmer than usual, it may allow oceanic predators to expand their range into salmon waters, preying directly on the salmon or on the salmon’s food.
Getting back to the problem of not enough chinook to make us happy fly anglers, the kings from the Sacramento to the Columbia have differences in their timing of ocean entry, live in different parts of the ocean, and as far as I am aware, have never ALL crashed at the same time in the last 60 years. Rivers like the Sacramento are heavily stocked with hatchery fish, but almost all of our Oregon Fall Chinook are wild fish – and ALL crashed at the same time.
The most optimistic signs I am aware of are 1) sampling by NOAA in the ocean in the last two years have indicated that the abundance of juvenile salmon and salmon food has been much higher than the previous several years; and 2) friends fishing Oregon coastal rivers the last two years have caught a lot of jack Chinook. Both observations point to increasing runs in the next several years. Good numbers of jacks in the last two years should mean that we will see more two- and even three-salt males this fall.
I’m going to close this rant with several observations that the previous post hinted at:
First, the run this year could be very low, so use discretion when fishing for and releasing fish. There are likely to be good numbers of wild silvers in the bays and if you can dial these fish in, it could be a great opportunity to catch and release bright coho in the lower estuaries where cool water will be the norm.
Second, be prepared to go easy on the kings, but be open to the possibility that there may be relatively more males in the three- to ten-pound range. These make great table fare. PLEASE discourage everyone you know from keeping the big females. Those eggs should go in the gravel, not in the bait bucket.
Third, advocate for protection of our home-water rivers and the wild fish they still support. If the ocean turns around, we could still have some glory seasons ahead.
Finally, and this is really important, don’t ever believe that hatchery fish are capable of producing consistently high runs of chinook in our coastal rivers. The Rogue River produced a return of close to a hundred-thousand wild kings in 2003 and 2004. Wild kings! The Sacramento run crashed even though there are zillions of hatchery chinook stocked there. In short, our best path to good chinook fishing on the coast is to limit our impacts, keep an eye on the Pacific Salmon Treaty monitoring information, refrain from expanding hatchery production, and make sure that the habitat in these wild-fish factories is adequately protected from development like urbanization, dam building, water withdrawals, logging, agricultural practices, and river-side trophy homes.