Some of what I’ve learned about fisheries in Alaska

I know I’ve mentioned the department of fish and game regulations in past posts about seining because of how they dictate our fishing schedule, but I don’t think I’ve said anything about how the programs actually work. Read on if you’re interested…

Numbers of salmon in this fishery had gotten really low a while ago, so the state of Alaska instituted a network of salmon hatcheries. They mimic, or augment, the natural salmon cycles by spawning salmon each season and releasing them into the wild to do what salmon do. They keep population numbers up, making sure that there's enough for the streams, the subsistence fishermen, and the commercial fishermen. The main way the hatchery cycle differs from the natural one, as far as I’ve been led to believe, is that when the salmon run home what they are running into is not a natural stream. Rather, they’ll go up the artificial run which might just end in a ditch or something. Supposedly, the program has been wildly effective, and the last few years have seen record catches. Potential flaws in the system: (1) A reduction in genetic diversity because the hatcheries reproduce only a small sample of the salmon population, and (2) Because they don’t use natural streams, the hatcheries don’t address the relationship between salmon life cycles and forest health, which is significant. Apparently the salmon—either decomposing at the top of a stream or feeding some other animal—provide some important nutrients that get carried pretty far into the forests, and the woods don’t do too well when there aren’t enough fish in the streams. (Vice versa, the streams don’t function properly when there aren’t enough trees, so there are constant political struggles between the loggers and the fishermen over which way the regulations over this delicate balance are going to swing.)

But, the second point might not be such a problem, because the way the Alaska Department of Fish and Game regulates fishing is all based on escapement numbers. That means they adjust where you’re allowed to fish to ensure a steady number of salmon running upstream. They test the waters constantly, and they open and close specific districts to seining based on the numbers they see. That’s why we don’t know when or for how long we’re going to be fishing until a day or two before we’re actually allowed to fish. What they’re trying to ensure is a consistent number of salmon running upstream, the escapement number. Enough salmon need to make it to their streams both to spawn and to keep the forests healthy. What I’ve been told is that, naturally, the numbers running upstream would vary pretty widely from year to year, so that one year the stream would be too full, there would be too many dead salmon decomposing, and essentially the stream would undergo some eutrophication. And then, the next year, only a few salmon would be able to reproduce in that stream, and the numbers would build up over a while until the stream got too full, and so on in a cycle. The salmon that managed to survive would be the fittest, so the population was continually evolving to meet new conditions—dietary, climactic, etc. Now, the regulations are aimed to ensure that the streams are as full as they can manage every year, which means that they get more or less the same number of salmon every year, and they have eliminated some of the competition that the natural cycles produced and, as a result, some of the natural selection.

So, there are potential consequences to both the hatcheries and the fishing regulations that could be quite serious in the long run, but it’s really too soon to tell. In the meantime, people seem to feel the programs are a huge success. The streams and the fishermen both get their salmon. Fisheries that were thought to be depleted past the point of return have recovered in numbers, and then some. I’m still learning about all of this, and what I’ve written here is just what I’ve gathered through word-of-mouth. More when I start wading through all the research that’s published about the programs…