Salmon Life Cycle

Railroad Reports Salmon Life Cycle
Dams Floods Lost Habitat


The Salmon Life Cycle

Salmon don’t live in streams – salmon live in watersheds. With this realization comes the appreciation that all things are connected, and that our actions may have unintended consequences on the life histories of many “downstream” species. Changes in stream flow resulting from dams and diversion can affect the timing and success of salmon migration. Low flow releases in the summer result in warmer water temperatures, which increase death and disease of salmonids, and give the Sacramento pikeminnow an added advantage.

The female coho digs a nest or “redd” with her tail, deposits more than 1,000 eggs and covers the eggs again with clean gravel as the male salmon fertilizes them.

Coho salmon feed on the vast resources of the ocean for three years before returning to spawn. In order to make it back to their spawning grounds, they require adequate flows.

Coho salmon return to the Eel River in the fall to spawn in the gravel beds of rivers and streams. It is always a surprise to see coho spawning in streams that are only 5-6 feet wide.

The fingerlings stay in the river for at least a year before heading downstream the estuary, where they make the transition to salt water and become “smolts. The larger the smolts are when they enter the ocean, the more likely they are to return to spawn.

The fry emerge in great numbers and feed for a few months as they grow to the”fingerling” stage. Their success in feeding depends partly on water clarity, since they are sight feeders. Turbid water decreases feeding success – clear water increases feeding success and the growth rate of the fry.

During and after the spawning process, salmon provide vital nutrients to other animals, including eagles, bears and other mammals who convey the ocean derived nutrients to the forest floor. The carcass- derived nutrients from thousands of spawning salmon was once huge, and supported a vast food chain, and nourished both aquatic and terrestrial ecosystems. Everything is connected.

Fish of the Eel photos by Rob Darby

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