2019 Coho and Steelhead Smolt Trapping Season Nearly Over

Checking a smolt trap in the rain in mid-May. Strong late season storms have interrupted smolt trapping this year. Still, more smolts than expected have been captured on Redwood Creek, and the smolts captured on Olema Creek have been larger than average.

NPS / Maritte O'Gallagher

May 2019 - The coho and steelhead smolt trapping season got off to a late start this year. It has also been interrupted by late season storms. Although May is not over yet, it has already been one of the wettest in recent history with over 4.5 inches recorded at the Bear Valley rain gauge. Still, the numbers of year-old smolts migrating out to the ocean have been especially promising on Redwood Creek where biologists are operating one of their two traps. So far, the monitoring crew has captured over 950 coho smolts there, exceeding expectations. The other trap, located on Olema Creek, has captured almost 100 coho smolts, fewer than anticipated.

Although the Olema Creek coho smolt numbers have been low, most smolts have measured in at more than 115 mm in length. Several smolts have even reached over 140 mm in length, much higher than average. In contrast, the Redwood Creek coho smolt population has had more variation in length, with smolts measuring from less than 90 mm to over 130 mm. Biologists like to see all outmigrating smolts measure over 100 mm in length, as the young fish will need as much of a size advantage as possible to survive in the ocean.

Crews will continue to operate the smolt traps through the end of May, by which point most coho smolts will have emigrated from their natal stream. Contact Michael Reichmuth to learn more.

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