Movement and mortality of stocked brown trout in a stream

Abstract

The movement and mortality of stocked brown trout Salmo trutta were investigated using radio telemetry. Four brown trout left the study area whereas the remaining fish were stationary. After 5 weeks, 13 out of 50 tagged brown trout were still alive in the stream. Surviving fish had a significantly lower mean movement per day than fish, which later either died or disappeared. This difference in behaviour was most pronounced 2 to 8 days after release. Predation by the otter Lutra lutra was probably the main cause of the observed mortality. # 2005 The Fisheries Society of the British Isles

Combining Radio and PIT-Telemetry to Study the Large and Fine-Scale Movements of Stocked and Wild Brown Trout (Salmo trutta L.) in a Northeastern Stream, Portugal

“…The dispersion of stocked brown trout is relatively well documented in the literature and, similarly to the present study, distinct individual movements were also found including stationary (maintaining the position near the stocking site) and mobile (ranging from upstream to downstream migrations) behaviour in the same stocked trout population (Cresswell, 1981). For example, Aarestrup et al (2005) found that four brown trout left the study area whereas the remaining fish (n= 46) were stationary. However, in our study it was observed a decline in the water flow that conditioned the potential displacement of fish during the radiotelemetry study (32 days).…”

“…Poor stocked brown trout survival rates were also reported in several studies (Pedersen et al, www.intechopen.com 2003; Aarestrup et al, 2005). The significant decrease in the condition of stocked brown trout suggested a lower ability to explore the available resources.…”

“…Probably the minor adaptation of hatchery-reared fish to the wild environment is more visible when stocking is made recurring to fish of superior size/age (> 1 + ). Although Pedersen et al (2003) had found a higher survival and adaptation of smaller brown trout (0 + ) over a period of 11 months, a longer time is needed to fish reach the legal catch size for anglers and, as referred by Aarestrup et al (2005), stocking with trout over the legal size limit could be the correct management tool for supplementing the recreational fisheries. Finally, it is important to consider alternative management techniques with low ecological risks like the improvement of the fish habitat and protective measures (e.g.…”

Distribution and movement of domestic rainbow trout, Oncorhynchus mykiss, during pulsed flows in the South Fork American River, California

“…Radio-tracking studies of rainbow trout, brown trout, bulltrout (Salvelinus confluentus), and cutthroat trout (Oncorhynchus clarki) under natural flow regimes are consistent in their findings that individual trout tend to remain in a small home area, generally <1 km, during non-spawning periods (Clapp et al 1990;Young 1996Young , 1998Knouft and Spotila 2002;Ovidio et al 2002;Schrank et al 2003;Aarestrup et al 2005;Popoff and Neumann 2005;Hojesjo et al 2007), but that they may move longer distances (e.g., 3-63 km) during migrations to spawning habitat (Bailey et al 1978;Meyers et al 1992;Brown and Mackay 1995;Swanberg 1997;Ovidio et al 1998;Burrell et al 2000;Hilderbrand and Kershner 2000;Meka et al 2003;Arnekleiv and Roenning 2004;Bahr and Shrimpton 2004;Bettinger and Bettoli 2004;Muhlfeld and Marotz 2005;Venman and Dedual 2005). In the South Fork American River rainbow trout would be expected to spawn in spring, as high winter flows recede.…”

Daytime habitat selection for juvenile parr brown trout (Salmo trutta) in small lowland streams

“…All of the above studies and others have shown that there is a positive correlation between fish size and water depth, and that the larger the trout, the deeper water it prefers (Greenberg et al, 1996;Heggenes et al, 1999;Maki-Petays et al, 1997). This preference for deep water could be explained by the possibility that parr may primarily be feeding nocturnally during summer (Alvarez and Nicieza 2003;Orpwood et al, 2006;Conallin, 2009;Conallin et al, 2012), and seeking refuge during the day to avoid predation (Aarestrup et al, 2003;Gwiazda and Amirowicz, 2006). Parr in small Danish lowland streams are vulnerable to avian predators such as grey heron (Ardea cinerea) and great cormorants (Phalacrocorax carbo sinensis) (Aarestrup et al, 2003;Jepsen et al, 2010Jepsen et al, , 2013 which are common species in many European countries.…”