Regionalized primary paleoproduction variability in the sea of Okhotsk during late Pleistocene and Holocene.

In order to reconstruct the history of primary paleoproductivity changes during the last 160 kyr in the Okhotsk Sea (OS), the high-resolution down-core analyses of chlorin content were performed on 11 sediment cores obtained from various part of the studied area with wide ranged depths. Spatial and temporal distributions of the marine phytoplankton paleoproductivity depend on sea ice condition and nutrient supply. The observed discrepancies among the reconstructed records allow us to separate out three main regions with specific environmental conditions. During glacial stages the paleoproductivity was depressed and vice versa. Productivity in the central region is low comparing to other regions due to nutrient limitation. Increased paleoproductivity in the southeastern area was affected by influence of nutrient-rich Pacific waters. [ABSTRACT FROM AUTHOR]