Kokanee Return Catastrophe

We have reached the mid-point of the annual kokanee return window and the results are not good.  So far survey observations have recorded a total of seven fish in all streams, and our brood year three years ago was 910 spawners and we released 46,000 fry from the hatchery program.

We had hoped for many more fish, even if not approaching historic levels…  0.5% survival of the hatchery fry alone would produce 230 spawners.

We haven’t seen two consecutive returns this poor since 2007-8 and 2008-9.  We can only guess if the return will improve from here forward. In some years the return window extends well into January, but at this point there is little cause for optimism.

There is already a conversation underway among technical folks addressing a few related issues:

  • Why are we seeing two catastrophically weak return years in a row?  Is there something happening in the lake that is causing unexpectedly high mortality? Did something happen in the natal streams during incubation that caused high mortality or otherwise compromised the fish?
  • Is there anything we can do during this return to either help protect/maximize the success of the spawning?
  • What actions should we be taking to ensure we are going to get the most out of the 2018-2019 return?  That return is the “strong” (in relative terms) cohort, so we are hopeful that it shows up better than the last two cohorts.

If you are out on the streams and see any kokanee, please send word to Dave Kyle at Trout Unlimited; dkyle@tu.org.