Large-Scale, Seasonal Movements of Radiotagged, Adult Bull Trout in the St. Mary River Drainage, Montana and Alberta
Mogen JT and Kaeding LR. 2005. Large-Scale, Seasonal Movements of Radiotagged, Adult Bull Trout in the St. Mary River Drainage, Montana and Alberta. Northwest Science. 79(4):246-253
Radio telemetry was used to determine the large-scale, seasonal movements and wintering areas of adult bull trout (Salvelinus confluentus) in the St. Mary River drainage, Montana and Alberta, between 1998 and 2003. The fish (n = 42; total length, 434–763 mm) had been radiotagged in their spawning creeks (river tributaries) during August–October. Data from automated, stationary radio receivers operated adjacent to the river showed the post-spawning and subsequent pre-spawning movements of tagged bull trout occurred during October–November and May–July, respectively. Searches conducted from the ground and aircraft during winter (December–April) found tagged fish (n = 22) distributed in the St. Mary River between the mouth of Lee Creek (Alberta) and Lower St. Mary Lake (Montana), and in the tributaries (n = 15 fish). Maximum stream distance between contact locations for individual fish (median, 25.5 km; range, 1–83 km) was not associated with fish length or weight when tagged. Some bull trout passed the St. Mary River diversion dam, although passage timing was not precisely determined and may have occurred when the dam was open. Nevertheless, upstream passage of some bull trout appeared to be impeded by the dam during pre-spawning movements, when the dam was closed for the irrigation season.
- Type
- Journal Article
- Authors
- Mogen, Jim; Kaeding, Lynn
- Units
- CRCO , GLAC
- Keywords
- Aquatic Sciences, Bull Trout, Fisheries, Salvelinus confluentus, Seasonal movement