Headquarters, Seattle Laboratory
Bull trout (Salvelinus confluentus)
Bull trout are a Department of the Interior trust species. Once common throughout the Western United States, they were listed as threatened under the Endangered Species Act in 1999. The Coastal-Puget Sound distinct population segment studied by WFRC biologists within the marine waters of Puget Sound has also declined considerably from historic levels. This population is unique as some individuals display an anadromous (feed in saltwater, breed in freshwater) life history. Studies conducted by the WFRC have been directed at understanding bull trout habitat use and life history. Using acoustic telemetry, research in Skagit Bay showed that bull trout used marine waters for 3-4 months. During this time they appeared to prefer shallow, nearshore habitats, areas that have been heavily impacted by human activities and are of special concern to Puget Sound managers. The WFRC has also worked in the Elwha River to collect data that will help to describe bull trout population trends before and after a dam removal. Information from both studies will assist managers in protecting critical habitat and will help to meet several high priority goals for the Puget Sound Management Unit. Future research has been proposed to study other populations within Puget Sound and to investigate new methods for ageing fish.