ALL ABOUT KOKANEE
the landlocked salmon
Wondering what the difference is between a kokanee and a sockeye? How big does a kokanee get, anyway? Learn more here
WHAT IS A KOKANEE?
Kokanee are a type of salmon, a family that includes sockeye, chum, pink, chinook, and coho. Pacific salmon typically hatch in freshwater rivers and streams, travel downriver to the Pacific Ocean to live their adult lives, and then return to the same freshwater location where they were hatched to spawn the next generation. This marks the end of the salmon lifecycle, and salmon will die shortly after breeding.
However, it is thought that around 15,000 years ago some of the ocean-going sockeye salmon started to inhabit freshwater lakes for their adult lives instead of running to the ocean like all of the other pacific salmon species do. The reason for this comparatively recent evolutionary occurrence is unknown, although it is theorized that changes in river flow forced hearty sockeye salmon to adapt to living in lakes when access to the ocean was cut off.
These freshwater-loving sockeye became known as kokanee, and are sometimes called "landlocked salmon."
Kokanee are native to the western coast of North America, from Alaska and the Yukon, through British Columbia, and as far south as California. Kokanee have also been found in Russia and Japan, and they have been introduced to other locations including New York. Kokanee are only found in deep, cold water- perhaps because this most closely mimics the temperature of the ocean.
SO HOW DO YOU TELL THE DIFFERENCE BETWEEN A SOCKEYE AND A KOKANEE?
Okay, you're saying. That's cool and all, but I caught this fish, and how can I tell what it is?
Because sockeye and kokanee are genetically similar, they look very similar: they are both a beautiful silver colour when mature and red and green when spawning, and both have the same fin pattern.
There are some visible differences between the kokanee and the sockeye:
Kokanee are smaller than sockeye, likely due to less food supply in freshwater lakes. An adult kokanee averages about 23 - 30 centimeters (9-12 inches) and weighs about one pound, although in some lakes the average is much bigger and they can grow as large as 5 pounds. An adult sockeye grows to 60 - 84 centimeters (24 - 30 inches) in length and weighs between 5 - 15 pounds.
Sockeye are stronger swimmers- a trait that comes in handy, given their astonishing travels upstream from the ocean to far-inland riverbeds. Sockeye have been known to scale waterfalls.
DID YOU KNOW?
Kokanee and sockeye return to the same breeding habitats, sometimes breeding side-by-side- but they will not mate together. Although kokanee and sockeye are capable of interbreeding, these two types of fish will avoid breeding with one another, even when kept together in captivity.
Of course, the easiest way to tell a kokanee is this: unless it's spawning season (August - October), if you caught your adult salmon in freshwater, it's most likely a kokanee.
LIFE CYCLE OF THE KOKANEE
Kokanee normally live to 4 years of age but some strains of kokanee can live to 7 years of age.
DID YOU KNOW?
Much like counting tree rings, the age of a kokanee (and other types of salmon) can be determined by counting rings on its scales. These rings are tiny, and are seen under microscope. Like tree rings, salmon rings are thicker in times of abundance and thinner in times of scarcity.
Kokanee nests, called redds, contain between 250 - 2000 eggs, and are laid in freshwater locations in the fall. The spawning grounds are usually creeks or rivers, but sometimes kokanee can be observed spawning on a gravel shoreline of a lake. The eggs develop over the winter, and hatch around February. The baby fish, called alevins, feed off yolk sacs attached to their bellies. When they become large enough, they are swept downriver to larger lakes. Here they will live out their adult lives, maturing over the next three or more years.
The natural end to a kokanee's life is generally between the months of September to November. During this time, kokanee will turn red in colour and their heads will turn green. The male will develop a pronounced crook to its lower jaw and a hump on its back. This is when kokanee will return to their birth place to spawn, and they typically die shortly after mating.
It is not entirely clear how salmon find their exact birthplace- even, sometimes, finding the same location after natural or man-made barriers such as dams or downed trees have made travel difficult. One theory is that they use their pronounced sense of smell to find the exact location they were hatched. Another theory is that they can recognize the the exact pattern of the earth's magnetic field at their birth location.
The sockeye salmon is the most sought-after salmon due to its deep red flesh and amazing taste. Much like the sockeye salmon, the kokanee salmon also has deep red flesh and tastes amazing. Not only tasty, the kokanee is full of omega 3s and is a healthy choice!
This is great news for us fish fanatics, because kokanee are an abundant fish and is a sustainable fishery!