Research Methods of China Marginal Seas Biogeochemical Process

3 Research Methods of China Marginal Seas Biogeochemical Process 

In China, studies of the marine enclosure ecosystem mainly include the following aspects the mutual interactions between nutrients and ph doplankton, the transportation of heavy metals, effects of heavy metals on the plankton, the metabolism of organic carbon, the grazing pressure on bacteria of zooplankton, and so on. 

With respect to the mutual interactions between nutrients and ph3do-plankton, both the continuous and intermittent input of nutrients can firstly cause diatom bloom and then dinoflagellate bloom. However, the intermittent input of nutrients can affect the occurrence time and dominant species of dinoflagellate bloom. Lin et al. (1994) found that after phosphorus addition into enclosure ecosystems, the macro-ph3doplankton were the major contributor to the total biomass of ph3doplankton in October, and micro-ph3doplankton in May. 

Heavy metals can cause inhibition of plankton, even in concentrations at ppb level. Among plankton, zooplankton, especially larvae zooplankton, are very sensitive to heavy metal pollution. In an enclosure ecosystem, concentrations of dissolved heavy metals decreased exponentially with deposition of particulates, with the removal efficiency Pb Hg Zn Cu Cd then the dissolved heavy metals were transformed to particulate forms by biological activities. After 27 d, Cd and Cu existed mostly in the dissolved form, most of Pb and Hg were transported to the bottom, and about half of Zn was transported to the bottom. The release of heavy metals from the sediments was determined by both the nature of the metals themselves and the environmental conditions. An anoxic environment is beneficial to the release of heavy metals. In an oxidizing environment, release fluxes of Cu and Zn were 1 2 order(s) of magnitude higher than those of Cd and Pb. 

In China, studies of the biogeochemical model have been developed since the 1990s. These studies were mainly related to budgets of biogenic elements 

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