Movement of rainbow trout (Oncorhynchus mykiss) during the spawning migration in the Tongariro River, New Zealand

Abstract

The movements of 74 rainbow trout (Oncorhynchus mykiss) were monitored every 2-3 days using radio-telemetry during the spawning migration up the Tongariro River, New Zealand, between June and November 1995. Contrary to the views of anglers, movements of individual fish were highly variable and upstream movement could not be predicted from environmental conditions and fish related variables (length, sex, and reproductive status). There was no significant difference in individual movement between male and female fish. When individual movements were in an upstream direction, maiden trout moved faster, but less often, than fish that had spawned in previous years. The flow in the lower river explained 9% of the variance in individual downstream movements. Net upstream movement occurred throughout most of the study period with above mean activity when the river was in spate, especially early in the migration season when fish responded to flow changes as low as 7%. Above mean upstream daily movement occurred 8 times on rising and 9 times on falling barometric pressure. Large floods caused downstream displacements, but fish tended to move up stream again on the flow recession. The most noticeable downstream movement occurred following the eruption of Mount Ruapehu. M98016

Movement and Mortality of Adult Brown Trout in the Motupiko River, New Zealand: Effects of Water Temperature, Flow, and Flooding

“…Faster movement has been recorded for brown trout moving upstream to spawning grounds (Ovidio et al 2002;Rustadbakken et al 2004;Svendsen et al 2004) and also downstream after spawning (Rustadbakken et al 2004). The movement rates we observed were also similar to the range of movement rates reported for spawning rainbow trout Oncorhynchus mykiss in New Zealand (321-487 m/d; Dedual and Jowett 1999;Venman and Dedual 2005), but lower than that reported for bull trout Salvelinus confluentus (up to 4.4 km/d; Swanberg 1997). The total distances moved by brown trout in our study (up to 41 km) were also within the range reported elsewhere for brown trout (Allen 1951;Clapp et al 1990;Meyers et al 1992;Burrell et al 2000;Knouft and Spotila 2002;Ovidio et al 2002;Bettinger and Bettoli 2004;Diana et al 2004;Rustadbakken et al 2004;Heggenes et al 2007), although somewhat less than the 76-202 km reported by Young (1994), Wilson and Boubee (1996), and Strickland et al (1999).…”

“…However, the effects of floods on adult trout appear to be less severe and unpredictable (Allen 1951;Seegrist and Gard 1972;Jowett and Richardson 1989;Lobon-Cervia 1996). Some studies have indicated that adult and juvenile trout displaced downstream by floods have returned upstream during the flood recession (Dedual and Jowett 1999;Dare et al 2002;Ortlepp and Murle 2003). Therefore, it is not clear whether the reduction in abundance associated with floods observed in some studies is due to displacement or direct flood-induced mortality.…”

“…Trout may also be swept downstream or out to sea. Some studies have indicated that fish displaced downstream by floods have returned upstream during the flood recession (Dedual and Jowett 1999;Dare et al 2002;Ortlepp and Murle 2003). As far as we are aware, there are few direct observations of trout mortality resulting NOTE from floods (but see Ortlepp and Murle 2003).…”

“…Once hooked, the time required to land the fish was minimized to limit stress. The fish were transferred to flow-through, vinyl holding bags, similar to those described by Venman and Dedual (2005), until they could be surgically implanted with radio tags (methods of Dedual and Jowett 1999). Following surgery, trout were placed in a large bin of freshwater, carried back to the river, and transferred to a holding bag.…”

“…Trout also seek refuge from adverse environmental conditions in winter (Cunjak 1996) and summer (Nielsen et al 1994;Ebersole et al 2003). Floods may also initiate longitudinal or lateral movement in fish, either to take advantage of easier passage during high flow conditions (Dedual and Jowett 1999;Natsumeda 2003) or in an effort to avoid the impact of floods (Jowett and Richardson 1994;Schwartz and Herricks 2005). Juvenile trout abundance tends to decline after severe floods (Jowett and Richardson 1989;Hayes 1995;Harvey et al 1999;Nislow et al 2002).…”