5900 36TH AVE W SEPA 015 - 034 - SOUNDVIEW BUSINESS CAMPUS - VERITAS Land Use Decision Documents 2025-04-22

COHO SALMON The life history of Coho Salmon is described in detail in Pacific Salmon Life Histories (Groot and Margolis, 1991) and is included herein by reference. A summary to assist in the discussion of effects of the proposed action is included below. Coho Salmon occur on the Pacific Coast from central California to Alaska. In Puget Sound, Coho generally return to their natal rivers in late summer and autumn after one winter at sea. Coho generally spawn from mid October though early January (Salmon Watcher). After an average incubation period of 42 to 56 days, fry emerge and spend up to 15 months in fresh water prior to migrating to the ocean. Fresh water, Coho depend on visual cues for locating food which primarily of insects. Once leaving rivers and estuaries, Coho enter the Pacific ocean where they range widely for on average a period of sixteen months before returning to spawn and die. STEELHEAD TROUT Steelhead (Oncorhynchus mykiss) occurs on the Pacific Coast from southern California to Alaska (NOAA Species of Concern). The life history of the Steelhead is more complex than any other species of anadromous fish (Barnhart 1986). These fish can be anadromous or fresh water resident. Resident fish are called rainbow trout while the anadromous strain are known as Steelhead (NOAA-NWFSC tech memo-27, NOAA Species of Concern). Steelhead generally spend from one to four years in fresh water prior to smoltification, and up to three years in salt water prior to first spawning. The average spawning age of these fish is four years (NOAA Species of Concern). In addition, Steelhead have the ability to spawn more than once (iteroparity). With the exception of 0. clarki, all other species of Oncorhynchus spawn once and then die (semelparity) (Barnhart 1986, NOAA-NWFSC tech memo-27, NOAA Species of Concern). Steelhead may be divided in to two categories, either winter run or summer run fish (Barnhart 1986, California Department of Fish and Game 1954, NOAA-NWFSC tech memo-27, NOAA Species of Concern). Of the two categories, winter Steelhead are the most common and occur in all coastal rivers of Washington, Oregon, and California (NOAA-NWFSC tech memo-27). Winter Steelhead enter freshwater in a sexually mature state between November and April, and spawn soon thereafter in April and May (Barnhart 1986, NOAA Species of Concern). Summer Steelhead are less abundant than winter Steelhead. These fish enter freshwater as immature fish between May and October and do not mature and spawn for several months, generally until January and February (Barnhart 1986, NOAA Species of Concern). Steelhead from both winter and summer runs may enter freshwater in the spring or fall and are then called spring or fall -run Steelhead. In some large rivers, Steelhead may enter freshwater throughout the year (Barnhart 1986, California Department of Fish and Game 1954). After emergence from their eggs, Steelhead fry spend from one to four years in freshwater before becoming smolts and migrating to saltwater (Barnhart 1986).