Diel and Interannual Variation of Size Distribution of Oceanic Zooplanktonic Biomass

摘要: A negative temperature anomaly with an increase in primary production affected the size distribution of zooplanktonic biomass central gyre North Pacific Ocean, a very large, old oligotrophic, and highly diverse ecosystem little seasonal change. Previous reports showed no effect this on species structure macrozooplanktonic community. Composite zooplankton samples from euphotic zone for five cruises corresponding to normal or steady state (two summers, two winters, one spring) perturbation (summer 1969) were fractionated by filtration through column 4, 2, 1, 0.5, 0.3, 0.183 mm mesh, after manual removal organisms larger than approx. = 8 mm. Total was higher during summer winter. Also, distributions more similar between summers winters different years seasons. Vertical migration causes important scale variability; size-differential (larger classes migrate smaller ones) has pattern: winter, all increases nocturnally zone; summer, nocturnal is due almost exclusively largest sizemore » classes. The effects climatic were: total biomass; elimination diel variability typical enhanced small animals, resulting being winter categories; dominance 0.5 -1.0 class.« less