Section 6.1: Two Case Studies From Washington’s Olympic Peninsula: Radio Telemetry Reveals Bull Trout Anadromy and Establishes Baseline Information Prior to Dam Removal
Stephen C. Corbett and Samuel J. Brenkman
The use of radio telemetry is a widely accepted fisheries technique being used to address numerous topics on juvenile and adult fishes in small and large river systems. A keyword search for “radio telemetry” in American Fisheries Society journals revealed a total of 265 published manuscripts on radio telemetry (accessed on 11 December 2008). For one species alone, the federally threatened bull trout Salvelinus confluentus, there have been 72 radio telemetry studies that involved ~3,000 tagged individuals throughout four U.S. states and two Canadian provinces (Dare 2006).
Radio telemetry studies have been conducted in a wide array of riverine systems on multiple fish species to better understand spatial and temporal movements (Curry et al. 2002; Zigler et al. 2003), identify distinct life history forms (Meka et al. 2003; Brenkman and Corbett 2005), and determine habitat preferences (Tyus et al. 1984; Muhlfeld and Marotz 2005). Radio telemetry techniques have also been used to evaluate fallback rates of fish over dams (Boggs et al. 2004), estimate sport fishing catch and release mortality (Bendock and Alexandersdottir 1993), examine diel movements (Snedden et al. 1999), and determine seasonal migrations and spawning ecology (Gray and Haynes 1979; Burger et al. 1985; Brown and Mackay 1995; Swanberg 1997; Hilderbrand and Kershner 2000; Schmetterling 2001; English et al. 2005).
Typically, the use of radio telemetry studies is confined to studies of fish movements in freshwater systems. However, radio telemetry has proven useful in understanding fish migrations between rivers and marine environments. Recent studies highlight the importance of radio telemetry in establishing the extent of anadromy, periods of marine residency, and the diverse range of freshwater, estuarine, and marine habitats used by fish that inhabit coastal watersheds [Curry et al. 2002; Brenkman and Corbett 2005; Welch et al. 2006 (acoustic and radio telemetry), Brenkman et al. 2007].