Comparative Injury, Adipose Fin Mark Quality, and Tag Retention of Spring Chinook Salmon Marked and Coded Wire Tagged by an Automated Trailer and Manual Trailer at Carson National Fish Hatchery

摘要

The United States Fish and Wildlife Services Columbia River Fisheries Program Office has been marking and tagging salmon with automated trailers consistently since 2006, in addition to the historically used manual trailers. Some hatchery managers have expressed concern that automated trailers may cause injuries at rates higher than historic marking and tagging techniques. To begin addressing these concerns, in 2006 we evaluated the two types of marking trailers at Warm Springs National Fish Hatchery, Oregon. To complement the study at Warm Springs National Fish Hatchery, in 2008 spring Chinook salmon at Carson National Fish Hatchery were adipose fin marked and coded wire tagged using both an automated and manual marking trailer. Fish injuries, fin mark quality, and coded wire tag retention rates were compared between the two trailers. Fish were randomly sampled from each trailer and evaluated in a single blind experiment. Injury rates, fin mark quality, and tag retention rates did not significantly differ between the two trailer types. The ability of these two types of trailers to tag fish without any differential injury, clip quality, or tag retention rates allows hatchery managers at Carson National Fish Hatchery to use either trailer with assurance that fish are being marked and tagged in accordance with the expected standards. Availability of experienced markers, cost, time constraints and many other factors should be considered when deciding what type of trailer to use when marking and tagging salmon at a particular fish hatchery.