The Lower Elwha Klallam Tribe has discovered that Lake Sutherland kokanee is a unique population, possibly related to Elwha River sockeye.
For nearly 15 years, the tribe has been studying the genetics and health of Lake Sutherland kokanee before, during and after the removal of the Elwha River’s two fish-blocking dams in 2011-2014. Lake Sutherland is connected to the river by Indian Creek.
Aside from annual testing for parasites, bacteria and viruses, scientists from the National Oceanic and Atmospheric Administration and the University of Washington studied the kokanee’s genetics and egg sizes.
“A genetics baseline showed that the Lake Sutherland kokanee population didn’t match up with other stocks in the state, including those that were planted in other lakes,” said Mike McHenry, the tribe’s habitat program manager. “This suggests that the Sutherland stock is unique and possibly related to the anadromous population in the Elwha River.”
The study showed that the eggs from Lake Sutherland kokanee were larger than other populations, also suggesting a link to their sockeye cousins, he said.
Unlike sockeye, kokanee spend their entire lives in fresh water. Because they don’t migrate to sea to feed, kokanee tend to be much smaller than their anadromous counterparts.
Like sockeye, kokanee spawn only once in their life cycle, typically in rivers and streams that are tributaries to lakes but also on lakeshores, mainly where groundwater comes up through gravel.
The tribe has observed adult sockeye in the lower Indian Creek, but there has been no documented adult sockeye in the lake, McHenry said. But there have been small numbers of sockeye smolts in the smolt trap on Indian Creek.
Lake Sutherland kokanee are prepped for testing of parasites, bacteria and viruses at the Lower Elwha Klallam Tribe hatchery. Photo: T. Royal
