CORRECTED: Final Steelhead Numbers

The official Deschutes steelhead season is from April 1 to March 31, so the 2018/2019 season is now over.  Today, PGE released their March monthly newsletter which stated that a total of 35 upper basin origin adult steelhead returned and were passed above the Pelton Round Butte project and released into Lake Billy Chinook.  Clearly, this is a dismal number.  You can see the number of smolts that were released downstream here.  Assuming that adult returns were from 2016 smolts that’s a return rate of only 0.87% (not 8.7%, I missed a decimal point in the original post).  There is hope for some improvement in the adult return count, however, if not the percentage.  In 2017 and 2018 steelhead smolt counts were much higher.  2017 was a better water year and in both years more smolts were planted.  Starting next year only smolts will be planted.  Read more about this here.

Dave Moskowitz of The Conservation Anger made two correct observations about my original post which I want to acknowledge. Most important was my very embarrassing mistake with simple division and missing a decimal point. There’s a big difference between a 0.87% return rate and a 8.7% rate. I was in a rush last night but there’s no excuse for that.

It is also true that my return rate analysis is overly simplistic and only broadly representational. We don’t know precisely from which age classes the returning adults originated. As a rule of thumb I have been told that most Deschutes steelhead are 2 year old fish, hence my use of the 2016 smolt count. It is likely that some fish were older and some younger. I appreciate the desire to have more precise understanding of this but don’t think it makes much difference from the big picture perspective, however. 35 returning adults remains a very low number.