A study of drift in the Kakanui River, New Zealand

摘要: The bottom fauna and drift in the Kakanui River, New Zealand, were studied for a period of one year. was dominated by Ephemeroptera Chironomidae. A diurnal rate found with maximum rates just after sunset. mechanism is postulated to account observed correlation decrease light intensity at sunset increase rate. There quantative change night occurrence comparatively large numbers mayfly nymphs Rhyacophilidae larvae. Lowest recorded during winter. close interrelationship between fauna: proportional similar that but modified differences behaviour animals, pieces algae, containing animals. During study flood occurred which halved density within three weeks denslty returned near its pre-flood value. Some species had higher densities than before it. Recolonization substrate animals could be followed interdependent changes samples. immediately occurred.