Piontkovski, S. A.Williams, R.Melnik, T. A.2024-02-072024-02-071995Piontkovski S. A., Williams R., Melnik T. A. Spatial heterogeneity, biomass and size structure of plankton of the Indian Ocean: some general trends // Mar. Ecol. Prog. Ser. - 1995. - Vol. 117. - P. 219-227.https://repository.marine-research.ru/handle/299011/13627Data from surveys carried out in 1982 and 1990 in the Arabian Sea, and the South and North Sub-equatorial Divergence regions of the Indian Ocean were used to analyse the spatial distribution and the size spectra of zooplankton in relation to primary production and hydrophysical dynamics on a scale of hundreds of kilometres. Spatial heterogeneity of biomass distributions increased with the size of organisms from phytoplankton to macrozooplankton The zooplankton abundance spectra changed with hydrodynamic regimes of water dynamics (cyclonic, anticyclonic eddies, frontal zones) and could be approximated by linear regressions in logarithmic scale. From values of the normalised spatial variance of plankton biomass components (phyto-, meso-, macroplankton) it is concluded that heterogeneous 'fields' of predators exist on more uniform 'fields' of prey. Biomass ratios of phytoplankton (chlorophyll a), microzoo-, mesozoo- and macrozooplankton form an inverted pyramid of biomass in the studied regions. Maximal slopes for zooplankton abundance size spectra have been observed in regions of maximum pnmary production, i.e in regions of high primary production the smallest zooplankton dominate the total zooplankton. This is also true for regions of high phytoplankton turnover. The ratio of primary production to herbivore production indicates that the highest efficiency of transfer from autotrophs to heterotrophs is carried out by the smaller zooplankton. The ratio of pnmary production to zooplankton biomass increases as the spectrum slope of the zooplankton abundance increases. This means that the ratio increases when small mesoplanktonic organisms become more dominant amongst the mesoplankton size range. Both types of relationships can be approximated by diminishing non-linear equations. The values of these 2 ratios can change an order of magnitude on a scale of hundreds of kilometres.enIndian Ocean, Size spectra, Zooplankton biomass