Presentation on theme: "Assessment of Bull Trout Populations in the Yakima River Watershed."— Presentation transcript:
Assessment of Bull Trout Populations in the Yakima River Watershed
Background Bull trout listed as threatened under ESA on June 10, 1998. Listed for Columbia & Klamath River DPS. USFWS recognized distinct bull trout populations in the Yakima River sub-basin.
Current Populations WDFW Salmonid Stock Inventory Report (1998) indicated 9 distinct bull trout populations in the Yakima sub-basin. Current data suggests a minimum of 13 spawning populations
Current Populations 7 populations isolated in upper basin reservoirs. Minimum of 6 fluvial populations in the Yakima River system. Redd count range: 4 redds for the weakest 233 redds for the healthiest.
Threats Isolation by dams, water withdrawals, de- watered streams; water quality problems associated with agriculture, forestry, grazing, roads, mining; over harvest, poaching, non-native species, residential and commercial development activities.
Goal Recover bull trout in the Mid Columbia Recovery Unit. This proposal was tailored to compliment the NWPPCs 2000 Fish & Wildlife program, the Yakima Sub-basin Plan and the Mid Columbia Recovery Plan.
Critical Information Gaps Connections between populations in the fluvial system. Lack of information in Cle Elum Lake drainage. Genetic composition. Movement (migration) patterns. Adult summer / winter areas.
Critical Information Gaps Juvenile rearing & downstream distribution. Identification & quantification of habitat. Distribution (presence/absence). Abundance. Spawning areas (new areas, refine current indexes).
Presence /Absence Surveys AFS Protocol procedures for detecting bull trout (Peterson et al. 2001). Backpack electro-fishing in small stream environments (NMFS Guidelines).
Population Abundance Snorkel surveys to locate staging areas. Refine or establish spawning index areas. Extrapolate abundance from redd counts. Mark-recapture estimates.
Radio Telemetry Studies Trap post spawned bull trout. Intercept bulls in main stem areas. Radio tag. Monitor migration / movement patterns. Determine summer/wintering areas, pre- spawn staging areas & fidelity to spawning tributaries.
Juvenile Distribution Studies Determine downstream distribution of early rearing juvenile bull trout via snorkeling procedures. Migrant (smolt) screw traps on larger tributaries to monitor movement.
Habitat Correlations Measure & correlate habitat & biotic attributes with the occurrence of juvenile bull trout (Dunham et al 2000). Measure habitat in spawning areas. Apply to other areas to determine potential spawning and rearing habitat.
Determine Genetic Composition Collect tissue samples for micro-satellite DNA genetic analysis. Tissue samples taken in conjunction with other fish handling activities.
Determine Limiting Factors Data from this study. Current data. Historical or archived information. Literature searches. Compare life history requirements to measured conditions. Incorporate limiting factors into existing databases.
Determine & Implement Management Actions Synthesize data & limiting factors. Generate management recommendations. BPA Reports & other publications. Information to MCRUT & others working to recover bull trout in the Columbia Basin. Assist MCRUT with bull trout recovery.
Benefits Columbia Connection Data on distribution, abundance, habitat and genetics will contribute to management, restoration and preservation of bull trout in the Columbia Basin. Augments other assessment and recovery efforts in the Columbia Gorge & in the upper Columbia/Wenatchee system.
Benefits Columbia Connection Consistent with and supports the vision of the NWPPCs 2000 Columbia River Basin Fish & Wildlife Program, the Yakima Sub- basin Plan, and the Mid Columbia Bull Trout Recovery Plan.
Benefits Columbia Connection Objectives designed to facilitate the 2000 Program directives by resolving key uncertainties associated with resident fish losses. Objectives can be measured and quantified. Information vital for implementing recovery in the Yakima arm of the Columbia basin.