Prediction of benthic macroinvertebrate composition using microhabitat characteristics derived from stereo photography

1. Benthic macroinvertebrate community and habitat features varying at the microscale (less than or equal to 0.09 m(2)) were measured on one sampling occasion in the Thredbo River, Kosciusko National Park, NSW, Australia. 2. Most of the substratum habitat variables were measured in three dimensions using stereo photography. This is the first time that this method has been used so extensively for this purpose in freshwater ecology. 3. Microhabitat variables most related to benthic macroinvertebrate distribution and abundance were selected with multivariate analyses included rock length, height, area and water velocity. Individual variables alone could not account for macroinvertebrate variation, indicating the importance of interactions among variables. 4. Nine selected habitat variables were used to predict macroinvertebrate taxonomic content of additional sites. Predictions were 87% accurate for taxa with a >50% chance of occurrence and 93% accuracy for taxa with a >70% chance of occurrence. Variability observed in macroinvertebrate assemblages at the time of sampling was largely physically controlled and highly deterministic.