The distribution and some ecological features of the main species copepods in the south Pacific in the spring-winter period

The zooplankton of the Subantarctic and Subtropical Convergence zone of the Pacific was investigated during the spring-summer season. The distribution of the biomass and the number of the main species of copepods were determined both by the hydrographic conditions and by the seasonal status of their populations. The age structure, and sometimes the sex ratio was distinct in the different parts of the area. In the Subantarctic the seasonal development of populations of copepods was markedey delayed. The ecologic heterogeneity of species living in the zone of subtropical and subantarctic communities contact zone supports the in crease of the stability of the ecosystem and decreases the amplitude of fluctuations of the plankton biomass.