CHINOOK – COHO SALMON CROSSBREED DISCOVERED

Though the discovery was initially announced in the fall of 2019, a November 2021 study published in Ecology and Evolution provides greater detail about the rare phenomenon. The researchers confirmed that the hybrid salmon naturally occur in the Cowichan River each year and that the event is “likely exacerbated by prolonged low water levels which limit habitat and delay Chinook salmon spawning.” The study highlights climate change as a likely driver of the phenomenon. The frequency of a hybrid salmon originating in the Cowichan River was 4.92 percent compared to non-hybrid salmon, according to the study.