Upstream Movements of the Benthic Invertebrates in the Speed River, Ontario

摘要: Investigation of the benthic fauna Speed River, Ontario, was carried out from June 1966 to September 1967. Upstream movement substantial numbers invertebrates detected using solid-walled traps with induced current, and Terylene net traps. The mechanism for this largely positive rheotaxis, but skototaxis release phototactic control probably governed distance covered. During winter, statistically greater occurred in areas adjacent banks than midstream, summer midstream contributed most migrants. Artificially darkening increased biomass moving into them. Movements upstream counteracted 6.5% downstream drift by 4% weight, no comparison relative travelled made. sufficient quantity species diversity account recolonization dried-out or erosion-denuded areas.