ISSN:
1095-8649
Source:
Blackwell Publishing Journal Backfiles 1879-2005
Topics:
Biology
Notes:
Diel patterns in the spatial distribution of rainbow and cutthroat trout were studied with stationary acoustic transducers, gillnets, and setlines in Spada Lake during summer thermal stratification. Four diel periods (dawn, 03.00–07.00 hours; day, 07.00–19.00 hours; dusk, 19.00–23.00 hours; night, 23.00–03.00 hours) and two horizontal strata (nearshore, bottom depth 〈 8 m; offshore, bottom depth 〉 8 m) were identified from fish distribution patterns. During the day, trout were almost exclusively offshore and their densities were highest at intermediate depths of the water column (4–16 m). From dusk to dawn, trout were in intermediate and shallow depths (0–4 m) of the offshore and nearshore strata. The mean depth of capture was significantly deeper for cutthroat trout (9 m) than for rainbow trout (3m). Both species primarily inhabited the epilimnion and metalimnion where temperature ranged from 22.5 to 11.0°C and were nearly absent from deeper, cooler waters. Dissolved oxygen levels ranging from 3.9 to 8.6 mg/l did not seem to influence trout distributions.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1111/j.1095-8649.1992.tb02566.x
