Friends of the Eel River have formally petitioned state and federal fisheries agencies to protect the summer steelhead of Northwestern California rivers under their respective Endangered Species Acts. These unique, and increasingly rare, fish are clearly distinct from more numerous and less vulnerable, winter-run steelhead.
“Given their critical conservation status, North Coast summer steelhead should be immediately listed as endangered,” said Friends of the Eel River Conservation Director Scott Greacen. The differences between summer steelhead and winter-run fish are stark. Summer steelhead generally enter freshwater in spring, spend the dry season in Coldwater Refugia, then spawn further up their watersheds than any other anadromous (sea-run) fish. Summer Steelhead include the largest adults of any steelhead and the strongest swimmers and highest-leaping fish of any salmonid. Unlike winter steelhead, summer steelhead enter freshwater as “bright” fish, with undeveloped gonads; they prepare to spawn over the summer while fasting, subsisting on a much higher level of body fat than Winter-run Steelhead. Thanks to significant technology-driven advances in genetic science, recently published studies have demonstrated that summer steelhead’s physiological and behavioral adaptations are the result of a specific genetic difference with winter steelhead. As well, this research shows that protection schemes which lump summer and winter run steelhead together, as the federal listing for Northern California steelhead now does, lead to the irrevocable loss of summer-run fish.