Lagunitas Creek Spawner Update

by Eric Ettlinger

Significant storms are bearing down on Northern California at the moment, which limited spawner surveys this week and will likely curtail additional surveys for a while. However, our limited surveys did find some very interesting things.

The storm just before Thanksgiving dropped more than three inches of rain and raised flows in Lagunitas Creek to over 400 cfs. That high water allowed the first coho spawners to migrate throughout Lagunitas and San Geronimo Creeks. Coho were seen spawning upstream of the Leo T. Cronin Fish Viewing Area as well as adjacent to the San Geronimo Golf Course, which are both near the upstream anadromous limits of those two creeks. MMWD biologists observed the highest level of spawning activity for November in eight years, including 30 coho salmon and 14 new redds.

Female chum salmon in Lagunitas Creek

The most interesting observation of the week, however, was of a chum salmon—a rare species for California, and more common in rivers from Oregon to the Arctic Ocean. Aside from a freak run of chum salmon in 2001, we’ve never seen more than a handful of these beautiful fish in Lagunitas Creek in a season, and no chum at all have been seen since 2006. When we first came upon this fish on her redd, we briefly saw blotchy vertical stripes before she darted upstream. When we next saw her a short distance upstream, she had changed her coloration to mostly gray with a dark horizontal stripe. This color changing ability is peculiar to chum salmon, and was fascinating to see. I got a quick photo of her (well, most of her) before she swam away again. It would have been great to see this fish in her full spawning glory, before her tail was worn from digging and fungus began to grow on her back, but hopefully we’ll see more of this species next month and in the years to come.