Submitted by Jenny De Groot, MSc.
Speckled Trout Consulting, LLC
One lesson learned is that you should never underestimate salmon. They find ways to get up waterfalls, slip through nets too small to do so, and apparently, spawn when you never imagined they would.
Nearly five months since the first sighting of spawners, coho fry have emerged at Coho Preserve! We documented over a hundred, less than 1.5-inch fry in the creek on April 14, with many more likely undetected. It was a welcome surprise in very unpredictable times.
Did you know? Coho salmon were observed in Cascade Creek as far back as the 1950s and are the only wild run of salmon known to exist in the San Juan Islands. Recent coho salmon returns are low throughout the state, similar to other salmon stocks. Coho is an important prey species for Southern Resident Killer Whales, particularly in autumn when Chinook salmon are less abundant. Coho salmon spend at least a full year in freshwater before entering saltwater, making them particularly vulnerable in island streams that typically run low throughout much of the year. The retention of water in island watersheds is critical for the survival and protection of our wild and native fish populations). Protecting unique places in the San Juan’s, like your Conservation Land Bank’s Coho Preserve, ensures that salmon have a place to rear, spawn, and hopefully, call home for many generations to come.
A local courtship
Two coho salmon (Oncorhynchus kisutch) were observed spawning at Coho Preserve last autumn, thanks to the collective efforts of local community members and to the voluntary, temporary relinquishment of water by Orcas Water Holdings (see Giving Local Salmon A Fighting Chance). This was a small return from the 2016 run, but a hopeful sign nonetheless.
One female salmon entered Cascade Creek last November 19 near the hamlet of Olga on Orcas Island and proceeded to build redds (nests) the following day (Nov. 20). Coho salmon, like all other salmon, build redds by excavating a depression in the streambed with their tail fin. The female then waits nearby for a suitor to join her and fertilize her eggs. After fertilization, she covers her redd with sediment to protect the developing eggs over winter. She may build a few more redds and repeat the process, but eventually, she will guard her final redd for as long as her decomposing body will hold her within the stream.
A second salmon was observed near the initial redd on November 21 and then promptly chased downstream by the first salmon. A territorial dispute? No additional encounters or salmon were observed. December 3 was the last day a salmon was observed in the creek, a female holding her position with a tattered tail fin. No carcasses were found to confirm that either salmon had spawned.
The San Juan County Land Bank will continue to monitor the development of these salmon over the coming year. Please remember to stay on trails and leash dogs to protect this sensitive environment. Fishing is not allowed at Coho Preserve, as this and other fish populations in Cascade Creek are too small to be harvested sustainably. If you would like to learn more about salmon recovery on our preserves, please contact Orcas Preserve Steward, Peter Guillozet at peterg@sjclandbank.org.
