Adult Returns

Photo: David Berman - Male coho salmon in Dutch Bill Creek.
Photo: David Berman - Male coho salmon in Dutch Bill Creek.

The number of returning adults is an important metric in coho salmon recovery, as these fish are the basis of future wild coho populations. NOAA Fisheries has established a recovery target of 10,100 adult coho salmon returning each winter to the Russian River basin.

2022/22 adult return update

We used PIT-tag data to estimate that 484 hatchery coho salmon adults returned to the Russian River Basin over the winter of 2021/22. This number is slightly above the previous 10-year average of 454.

The 2021/22 spawner season started with incredibly wet conditions in October, followed by extremely dry conditions from January on. This unusual precipitation pattern impacted returning salmon and steelhead in strikingly different ways. Even the smallest streams were accessible during the December-through-January peak of the coho run. Coho were documented in 19 of 31 coho salmon streams surveyed (61%)--more than the 49% average observed over the past six years. The low winter flows that occurred during most of the late-January through early-April steelhead migration window, however, appeared to limit access to upper stream reaches and smaller tributaries. The number of steelhead redds observed was less than half of the lowest estimate from the past seven years. Despite this, steelhead distribution was close to the previous five-year average (63%), with steelhead presence documented in 61% of streams surveyed.

Estimated hatchery coho salmon adult returns to the Russian River basin from 2000-2022.
Estimated annual adult hatchery coho salmon returns to the Russian River, return winters 2000/01 through 2021/22. Note that methods for counting/estimating the number of returning adult coho salmon were not consistent among years; prior to 2009/10, spawner surveys were the primary method, from 2009/10 – 2011/12 methods included spawner surveys, video monitoring and PIT tag detection systems, and beginning in 2012/13, with the installation of the Duncans Mills antenna array, PIT tag detection systems were the primary method used. Juvenile stocking numbers and strategies varied significantly across years, contributing to the large uptick in adult return numbers.

See our Winter Monitoring Reports for more information on adult sampling methods and outcomes. 

Check out these videos of salmon spawning in our local streams: