Investigations of scales of changeability of biogeochemical processes on the Okhotsk Sea Shelf

Complex investigations of spatial-temporal changeability of biogeochemical processes and parameters were conducted on the north-eastern shelf of Sakhalin. They included: (1) transformation of the size and chemical composition of particulate matter by hydrophysical and biological factors; (2) the shift of equilibrium into the carbonate system of water masses in relation to variable physico-chemical and biological parameters; and (3) change of biomass and species phytozooplankton and the same amount of primary production connected with fluctuations of hydrophysical, physico-chemical and biological characteristics of water masses. Observations conducted during the last 3 years in different seasons, apart from winter, were by way of polygon survey and daily stations. Mathematical treatment of the data made it possible to estimate quantitatively the correlation between separate parameters and to identify the influence of several external factors on their spatial-temporal changeability: seasonal variations; the significance of the Amur river discharge; tidal motion of waters; steady circulation; invasion of CO2 from low-temperature hydrothermal sources on the sea bottom. The obtained dependencies can be used for forecasting possible ecosystem changes during the industrial exploitation of the oilfield