The pink salmon return to Kodiak was huge this summer, boosting the local economy, providing food for animals ranging from seagulls to killer whales, and offering a fish and wildlife lover like me a thrill.
I consider the life cycle of a Pacific salmon to be one of nature’s most fascinating enigmas, and I often wonder how a fish evolved such a complicated existence. Salmon face so many perils in their short lives; I’m amazed any of them manage to make it back to their birth streams to spawn.
Salmon lay their eggs in the late summer or early fall, just before the rainiest part of the year here on Kodiak. We often have rain for several days in a row in September and October, swelling the small streams and rivers to more than twice their natural size. The force of this excess water rushing downstream can wash the eggs from their nests before they have a chance to hatch. The flooding may also cause the river to change course, and when the flooding subsides, salmon nests that were previously underwater might now lie in a dry streambed.
A harsh winter can freeze the lower parts of a steam, killing the eggs or the small alevins after they hatch. Ice can also scour a river, taking salmon eggs with it as it moves downstream to the ocean.
Once a fry emerges from the gravel of the streambed, it is a tasty morsel for nearly any fish bigger than it is. It must sneak downstream at night and huddle with other young salmon nearshore in the ocean while it grows and readies itself for a trip to sea.
As a salmon grows larger, its chances for survival improve, and in the open ocean, it has fewer predators. Once a salmon begins its migration back to shore toward its home stream to spawn, though, everything wants to eat it. A pink salmon must dodge seals, porpoises, sea lions, sharks, killer whales, halibut, eagles, bears, humans, and other predators. It is not uncommon for us to catch a salmon while sport fishing and find the fish has marks on it from a commercial fishing net or a seal bite. I always feel bad for a fish that has escaped a net or a seal only to be caught by us.
While a salmon swims this gauntlet of predators on its return to spawn in its birth stream, it is undergoing incredible physiological transformations. Its color and shape changes, its kidneys must adapt from a saltwater environment to a freshwater stream, and it stops eating while its digestive system degrades. During the last few weeks of its life when it enters its natal stream to spawn, the salmon must draw on its stored energy reserves. After it spawns, its organs shut down, and the salmon dies a slow, ugly death.
I look at a salmon in the river in the fall. It is often covered with fungus and is so weak it can no longer swim against the current. While it is a sad sight, I can’t help but admire the fish. It made it home to spawn. It may not look like it, but this salmon is a survivor!
I am excited to announce the e-book of my novel, The Fisherman’s Daughter, is now available for pre-order.
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