Abstract |
The objectives of the report were to determine if there was any diurnal variation in the amount of drift; what organisms were present in the drift; and to evaluate several physical parameters, including light intensity, water temperature and stream discharge with respect to their influence on the drift of macroinvertebrates in Goldstream Creek. Ephemeroptera (Mayflies) and Diptera (two-winged flies) were the only orders represented consistently within the drift. Ephemeroptera exhibited a definite diurnal periodicity during the second, third and fourth (of four) sampling periods, while Diptera exhibited a similar periodicity during the third and fourth sampling days. Both orders peaked in abundance, as caught with a drift net, after sunset. The greatest numbers of both orders captured during the study were collected on the sampling day during which the highest water temperature was measured. |