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Decay And Rebirth

Post by Ranger Jacqi Terry of Katmai National Park

The gilded yellow leaves of autumn have all but blown away as the shorter days of October give way to the oncoming winter. The fertility of the Katmai landscape seems almost silenced by the bitter wind and unforgiving frost that accompany the end of an Alaskan fall. The brown bears of Brooks River continue to peruse the river currents for dinner before they make their yearly journey to their den site. Perhaps hoping for a silvery flash of fresh sockeye salmon, the bears will have to make do with their carcasses instead.

But throughout this steady passage into the waiting room of winter, life still stirs. If you were to snorkel the Brooks River or Naknek Lake and peer into the milky blue waters, you’d see thousands upon thousands of dead salmon lining the waters’ shore. Upon closer inspection, you may see some strange growths on their bodies —algae perhaps? Some sort of fungus? Lift one up and you might see a caddis fly larvae ripping into the leftovers, and as you come up to the surface you may glimpse a rainbow trout snap up a floating piece of decaying flesh stirred by the current.

Soon enough, it becomes clear that the sockeye salmon’s sacrifice hasn’t been all for naught. Though we are used to fresh salmon on our dinner plates and have probably heard that it is a coastal brown bears’ favorite meal, throughout all seasons salmon provide the watersheds and ecosystems in which they procreate an incredible influx of much needed nutrients and fertilizers. Every living thing within or surrounding a salmon river uses their bodies and eggs as food—from bears to weasels, eagles to seagulls, trout to char, and even insects. This helps to bolster the health and fertility of local environments, of which Katmai National Park is one.

Even trees are in on the deal. How? Imagine this: when a brown bear catches a salmon, they will often bring the fish into the forest to eat in solitude. What the bear doesn’t eat is left to decompose and break down into the soil, eventually providing fertilizer for nearby trees. Still don’t believe it? Scientists are able to tell that a tree has “eaten” a salmon by analyzing it for a certain isotope of nitrogen called N-15 which ismarine-sourced, or rather, found in the ocean. This isotope in turn can only be converted into a useable form by aquatic life like fish, and so even spruce trees get their fair share of the feast.

Though the sight of thousands of rotting fish may seem grisly, it is in fact a great reminder of the importance of these beings to Katmai’s ecosystems and Alaska’s environment as a whole. Without their contribution, the sport-fishing would be sub-par, riverine ecosystems would be far less enriched, and the incredible congregation of brown bears we see at Brooks River each year would be no more.

So, as the days get shorter, the nights longer, and the air cooler, we must thank the sockeye for giving their lives so that the rest of Katmai’s creatures may thrive.