Search

Search Results

• 1. [Article] Status of Oregon Stocks of Coho Salmon, 2004 through 2008 Report Number: OPSW-ODFW-2009-3

  Abstract -- This report summarizes five years of monitoring status and trend in Oregon’s naturally spawning coho salmon (Oncorhynchus kisutch) populations. The five coho run years reported are 2004 through ...

  Citation × Citation Citation Abstract Copy Title: Status of Oregon Stocks of Coho Salmon, 2004 through 2008 Report Number: OPSW-ODFW-2009-3 Abstract -- This report summarizes five years of monitoring status and trend in Oregon’s naturally spawning coho salmon (Oncorhynchus kisutch) populations. The five coho run years reported are 2004 through 2008. Monitoring results include: abundance of naturally spawning coho; density of spawning coho; coho spawn timing; and proportion of hatchery (marked) coho in naturally spawning populations. These results are based on data from randomly selected spawning surveys, as well as other methods in areas without adequate random surveys. Results for coho standard spawning surveys, as well as spawning surveys for other species are covered in data summaries and reports posted on an Oregon Department of Fish and Wildlife (ODFW) web page (see: http://oregonstate.edu/dept/ODFW/spawn/index.htm). Monitoring occurs at three hierarchical spatial scales, as defined by the National Marine Fisheries Service (NMFS): Evolutionarily Significant Unit (ESU); Stratum; and coho Population. There are three coho ESU’s located entirely or partially within the State of Oregon: the Lower Columbia River (LCR) Coho ESU; the Oregon Coast (OC) Coho ESU; and the Southern Oregon/Northern California Coasts (SONCC) Coho ESU. This report summarizes results for coho populations in the portion of each ESU that is within the State of Oregon. In the Oregon portion of the LCR Coho ESU sufficient surveys were conducted to meet precision goals at the ESU level three out of the five sampling years. At the population complex scale, yearly precision goals were rarely met. Wild spawner abundance remained fairly stable over the five sampling years; hatchery abundance was more variable. Regional patterns in fish distribution, spawn timing, and hatchery proportion are apparent at both the stratum and population scale. In the Oregon Coast ESU sufficient surveys were conducted to meet precision goals at the ESU level in all five sampling years, however at the population scale, precision goals were rarely met. Wild spawner abundance declined over the first four sampling years, but showed a significant increase in the fifth sampling year. The proportion of hatchery fish was generally low, but variable over the five sampling years. Only two populations, Salmon River and North Umpqua River, consistently had over 10% hatchery fish on the spawning grounds. Regional patterns in fish distribution, spawn timing, and hatchery proportion are apparent. Inadequate funding and the need to update the GRTS sampling frame continue to hamper monitoring of the Oregon portion of the Southern Oregon/Northern California Coasts Coho ESU. In the Oregon portion of the ESU insufficient surveys were conducted to meet precision goals at the ESU level in any of the four years when GRTS surveys were done. However, estimates of wild coho spawners were obtained in all five years based on Huntley Park seining. Wild coho spawner abundance declined substantially over the five run years; but the proportion of hatchery coho spawning naturally was fairly low and stable. Regional patterns in fish distribution, spawn timing, and hatchery proportion are apparent. Title: Status of Oregon Stocks of Coho Salmon, 2004 through 2008 Report Number: OPSW-ODFW-2009-3 Abstract -- This report summarizes five years of monitoring status and trend in Oregon’s naturally spawning coho salmon (Oncorhynchus kisutch) populations. The five coho run years reported are 2004 through 2008. Monitoring results include: abundance of naturally spawning coho; density of spawning coho; coho spawn timing; and proportion of hatchery (marked) coho in naturally spawning populations. These results are based on data from randomly selected spawning surveys, as well as other methods in areas without adequate random surveys. Results for coho standard spawning surveys, as well as spawning surveys for other species are covered in data summaries and reports posted on an Oregon Department of Fish and Wildlife (ODFW) web page (see: http://oregonstate.edu/dept/ODFW/spawn/index.htm). Monitoring occurs at three hierarchical spatial scales, as defined by the National Marine Fisheries Service (NMFS): Evolutionarily Significant Unit (ESU); Stratum; and coho Population. There are three coho ESU’s located entirely or partially within the State of Oregon: the Lower Columbia River (LCR) Coho ESU; the Oregon Coast (OC) Coho ESU; and the Southern Oregon/Northern California Coasts (SONCC) Coho ESU. This report summarizes results for coho populations in the portion of each ESU that is within the State of Oregon. In the Oregon portion of the LCR Coho ESU sufficient surveys were conducted to meet precision goals at the ESU level three out of the five sampling years. At the population complex scale, yearly precision goals were rarely met. Wild spawner abundance remained fairly stable over the five sampling years; hatchery abundance was more variable. Regional patterns in fish distribution, spawn timing, and hatchery proportion are apparent at both the stratum and population scale. In the Oregon Coast ESU sufficient surveys were conducted to meet precision goals at the ESU level in all five sampling years, however at the population scale, precision goals were rarely met. Wild spawner abundance declined over the first four sampling years, but showed a significant increase in the fifth sampling year. The proportion of hatchery fish was generally low, but variable over the five sampling years. Only two populations, Salmon River and North Umpqua River, consistently had over 10% hatchery fish on the spawning grounds. Regional patterns in fish distribution, spawn timing, and hatchery proportion are apparent. Inadequate funding and the need to update the GRTS sampling frame continue to hamper monitoring of the Oregon portion of the Southern Oregon/Northern California Coasts Coho ESU. In the Oregon portion of the ESU insufficient surveys were conducted to meet precision goals at the ESU level in any of the four years when GRTS surveys were done. However, estimates of wild coho spawners were obtained in all five years based on Huntley Park seining. Wild coho spawner abundance declined substantially over the five run years; but the proportion of hatchery coho spawning naturally was fairly low and stable. Regional patterns in fish distribution, spawn timing, and hatchery proportion are apparent. Close