Sunday, October 13, 2013

The Kokanee Are Running!

Back in the 1940s, somebody - eager fishermen, perhaps- decided to take Sockeye Salmon from the Pacific Ocean and introduce them to Lake Tahoe. These days it is generally considered inappropriate to move species to areas where they haven't previously existed. (Remember the agricultural inspection stations - the "bug stations” - at all of the highways coming into California. The reason is that introduced species often wreak havoc in their new territory, displacing native species and eating crops.)
Whether it was a good or bad decision to bring in the Sockeye - there's evidence both ways - these introduced Sockeye Salmon took well to Lake Tahoe. As a saltwater fish that used to return to freshwater streams only to spawn, these Sockeye turned out to be fine living in fresh water all year long. As a now-land-locked freshwater fish, they've been renamed Kokanee, a Native American word for freshwater silver trout.
Like their saltwater forebears, Kokanee spawn by swimming up the creek or river where they were hatched.
Taylor Creek on the South Shore of Lake Tahoe flows from Fallen Leaf Lake to Lake Tahoe. Of all the 60+ streams that flow into Lake Tahoe, Taylor Creek is the main spawning area for Kokanee Salmon.
Each fall, a portion of Tahoe's Kokanee turn from silver blue to brilliant red as spawning approaches. Then they return to their birth site and swim up Taylor Creek to spawn and die, their bodies providing a feast for our bears and Bald Eagles among other carnivores. 
Kokanee live for several years before they spawn, so most of the population don't spawn in any given year. Because they die after their first and only spawn, Kokanee are known as semelparous fish, coined for Latin for "beget just once." The colloquial phrase is "Big Bang reproduction."
How do the fish know where to go for this one-time event? It is a mystery, this combination of chemistry and scent and mapping and navigation hard-wired into their DNA. Is there something else? Is there learning involved? Because Kokanee live for several years, do the younger fish learn by watching the older fish go to their spawning grounds and then die?
It used to be that people thought fish had little if any intelligence. But recently, studies have shown that fish can recognize their friends! We've underestimated the intelligence of nearly all animals. So what about fish? Do they observe their elders and figure out what to do next?
Either way, it is a spectacle to observe. When I checked out Taylor Creek a few days ago, there were thousands of fish.
Most years, the Kokanee run begins in early October.
To get there, drive from South Lake Tahoe north on 89 (Emerald Bay Road) about 3.5 miles. Taylor Creek is easy to spot as it is a good-sized creek, and there is a bike/walking path bridge just to the north of the vehicle bridge. You can't park right near Taylor Creek, but you can park at the side of the highway a bit farther from the creek. During the salmon run, you will see lots of parked vehicles, the occupants of which are all wandering the areas near the creek.

Look at the color of this guy flashing through the fast water just below a cataract.

Looking upstream toward Fallen Leaf Lake. Taylor Creek flows about 2 miles to Lake Tahoe.

People congregate on the bike path bridge to watch the salmon.

Looking down from the bridge, the Kokanee Salmon are coming upstream, toward  us.

Where the water is slow, the fish rest in a group of thousands.

The mountain water from Fallen Leaf Lake is crystal clear.


  1. Such interesting history lesson. Customers have brought us some kokonee claiming they are a cross between trout and salmon - now I know the truth. Thank you.

    1. You're welcome!
      It is interesting that this particular saltwater fish can survive in fresh water. Most probably couldn't. I remember reading years ago about the biology of fish. Freshwater fish have cellular processes designed to conserve salt, while saltwater fish have processes designed to expel salt. It might make sense that in the process of adapting to fresh water year-round, salmon could become more similar to trout...