|The effect of cloud cover on the development of habitat quality indices for juvenile Atlantic salmon (Salmo salar)|Girard, P.; Boisclair, D.; Leclerc, M. (2003). The effect of cloud cover on the development of habitat quality indices for juvenile Atlantic salmon (Salmo salar). Can. J. Fish. Aquat. Sci. 60(11): 1386-1397. dx.doi.org/10.1139/f03-118
In: Canadian Journal of Fisheries and Aquatic Sciences = Journal canadien des sciences halieutiques et aquatiques. National Research Council Canada: Ottawa. ISSN 0706-652X, more
Salmo salar Linnaeus, 1758 [WoRMS]; Marine
|Authors|| || Top |
- Girard, P.
- Boisclair, D.
- Leclerc, M.
We tested the validity of the predictions made by a habitat probabilistic index (HPI) developed using a description of the physical conditions (depth, flow velocity, grain size) used and avoided by parrs during days of different cloudiness. Thirteen surveys were designed to estimate the number and the distribution of parrs actively foraging within a 300-m reach of a river. During these surveys, the number of parrs actively foraging ranged from 12 to 118, cloud cover ranged from 5% to 100%, and water temperature ranged from 16.5 °C to 21.7 °C. The number of parrs actively foraging was negatively related to cloud cover (r2 = 0.44 to 0.88) but was independent of water temperature. HPI models developed under low (<33%) and intermediate (34-67%) cloud cover explained 82% to 98% of the local variations of fish density. The HPI model developed under high cloud cover (67-100%) was unable to predict fish distribution observed during cloudy days. Our results suggest that HPI models developed when cloudiness is >67% may have a limited predictive power.