End of the 2017/2018 Deschutes Steelhead Season

The Deschutes steelhead season officially ranges from April 1 until March 31.  Below is a table with the final returns of adult fish to the trap at the base of PGE/CTWS’s Pelton Round Butte complex of dams.  There’s no way to sugar coat the news, it’s simply bleak.  There were record low returns of steelhead across all categories (see the table below). 

As I have written about previously, there are a range of causal factors.  Dams, habitat loss, sea lion & avian predation, over fishing, and pollution all play a role.  The scientific consensus, however, is that poor ocean conditions are currently the primary factor.

A few years of abnormally warm ocean temperatures has severely disrupted the food chain causing a large percentage of steelhead smolts to starve when they hit the salt.  This issue is not confined to the Deschutes as steelhead returns have plummeted for most runs in the Pacific Northwest.  Unfortunately, there does not appear to be much basis for hope that the North Pacific will return to normal temperatures soon.

That being said, there are some significant gaps in our understanding of what precisely is going on.  When I have had the chance to talk about this topic with ODFW biologists, including the head of the fish division, they state that the ocean is really a “black box”.  Why are steelhead returns on some river systems doing a little better than others?  Why were there such fantastic returns of sockeye salmon to the Deschutes last year when steelhead returns collapsed?

There is speculation about “left turning” versus “right turning” fish (heading north or south when they hit the ocean).  There are timing differences between sockeye, chinook, and steelhead entering the ocean (steelhead are last out).  There is also reason for a little hope in two years when steelhead adults return from last spring’s record steelhead smolt out migration.

Nevertheless, the overall picture is simply depressing.

Year Upper Deschutes Origin
Round Butte Hatchery Stray Hatchery
2014-15 93 2483 390 174
2015-16 45 2162 215 57
2016-17 30 2068 175 43
2017-18 17 1669 153 27

Upper Deschutes Origin: fish that were planted in rivers above Lake Billy Chinook.  These fish were returned to Lake Billy Chinook in the hope that they would naturally spawn in the Crooked, middle Deschutes, or one of their tributaries.

Round Butte Hatchery: fish raised in the hatchery at the PRB complex.  These fish were killed.

Stray Hatchery: fish from hatcheries on other rivers.  These fish were kille

Wild: fish that naturally reproduced somewhere below the PRB complex.  These fish were returned to the Deschutes.