Diversity of movements by individual anadromous coastal cutthroat troutOncorhynchus clarkii clarkii

Abstract

Wild, downstream-migrating cutthroat trout, Oncorhynchus clarkii clarkii, smolts and adults were captured at a weir in Big Beef Creek, Hood Canal, Washington, surgically implanted with acoustic tags and tracked to identify spring and summer movements using stationary receivers in order to test the assumption that the species moves little while in marine waters. Overall, 93-96% migrated from the stream into the east side of the long narrow fjord, where they dispersed north and south along the shoreline. Most O. c. clarkii were detected nearshore within 10 km of the release site, with declining detection rates to 77 km. Over one-third (36%) crossed c. 2-4 km of deep water to the other side but only one O. c. clarkii left the Hood Canal basin. Movements and behaviour patterns did not differ between smolts and adults but cluster analysis revealed two modes of distribution, here categorized as residents and migrants. Within these categories of overall distribution, a range of finer-scale behaviour patterns was observed, including sedentary individuals, daily moving between proximate sites and more continuous long-distance travel. Diel movement patterns varied markedly among individuals but overall activity increased near dawn, peaked around mid-day and declined but continued at night. These patterns contrast with sympatric and closely related steelhead trout, Oncorhynchus mykiss, providing new insights into the diversity of salmonid behaviour.

Size, age, growth and site fidelity of anadromous cutthroat trout Oncorhynchus clarkii clarkii in the Salish Sea

“…The only exception to this pattern is the anadromous form of coastal cutthroat trout Oncorhynchus clarkii clarkii (Richardson 1836). Recent studies in the fjord‐like inlets of south Puget Sound and Hood Canal in Washington State, USA, have shed light on broad‐scale migratory patterns of anadromous O. c. clarkii (Goetz et al ., ; Losee et al ., ; Moore et al ., ) and demonstrated that they undergo short marine migrations relative to other Oncorhynchus spp. (Daly et al ., ).…”

Foraging mechanisms of siscowet lake trout (Salvelinus namaycush siscowet) on pelagic prey

“…Genetic differences between the morphotypes (Goetz et al, 2010) result in higher lipid production in siscowets, resulting in 30-70% body fat composition compared to 20% in lean lake trout (Eschmeyer and Philips, 1965;Wang et al, 1990). Greater lipid levels may be adaptive for regulation of buoyancy in the deeper water and may facilitate DVM (Eshenroder and Burnham-Curtis, 1999;Goetz et al, 2013). Nitrogen is more soluble in fatty tissues than lean tissues, and greater lipid content may allow for quicker vertical migrations (changes in pressure) without associated barotrauma as a result of nitrogen escaping leaner tissues (Shilling et al, 1976).…”

Potential of a no‐take marine reserve to protect home ranges of anadromous brown trout (Salmo trutta)

“…Previously, low biodiversity has been observed at sampling stations in Zone 2, close to the border between Zone 1 and 2, indicating a reduced selection of prey for sea trout in this habitat (Kroglund, Dahl, & Oug, 1998). Salmonids have shown great differences in movement rates contrasting day and night (Alanärä, Burns, & Metcalfe, 2001;Candy & Quinn, 1999;Eldøy et al, 2017;Goetz, Baker, Buehrens, & Quinn, 2013), and it has been shown for steelhead trout (Oncorhynchus mykiss) that horizontal movement rates increase twofold during daylight compared to night in the marine habitat (Ruggerone, Quinn, Mcgregor, & Wilkinson, 1990). There were significantly more excursions from the reserve during day than night, implying greater horizontal movement during day.…”