Description: Continental margin ecosystems in the western North Pacific Ocean are subject to strong climate forcing and anthropogenic impacts. To evaluate mechanisms controlling phytoplankton biomass and community structure variations in marginal sea-open ocean boundary regions, brassicasterol, dinosterol and C37 alkenones were measured in suspended particles in summer and autumn from 2012 to 2013 in the northeastern East China Sea and the western Tsushima Strait (NEECS-WTS). In summer, the concentrations of brassicasterol (40 - 1535 ng L-1) and dinosterol (4.2 - 94 ng L-1) were higher in the southwest of Cheju Island, while C37 alkenones (0 - 30 ng L-1) were higher in the south of Cheju Island. In autumn, brassicasterol (12 - 106 ng L-1), dinosterol (2.4 - 21 ng L-1) and C37 alkenones (0.7 - 7.0 ng L-1) were higher in the southwest of Cheju Island and the WTS, and higher C37 alkenones also occurred in the Okinawa Trough. Correlation analysis of biomarkers and environmental conditions (temperature, salinity and inorganic nutrient concentrations) clearly demonstrated that phytoplankton biomass and community structure variations can be well elucidated by water masses as indexed by temperature and salinity. High nutrients from the Changjiang River were the main cause of high biomass in summer, while nutrients from subsurface water were likely the key factor regulating phytoplankton biomass in open ocean water stations in autumn. This study indicates that mechanisms controlling phytoplankton biomass in marginal sea-open ocean boundary regions should be classified by various water masses with different nutrient concentrations, instead of by geography.

Description: A dataset of 42 collected surface sediment samples from the East Siberian Sea by analysis of Arctic sea ice (IP25) and open water phytoplankton biomarkers (Brassicasterol, Dinosterol, HBI-III and HBI-IV). Terrigenous sterols (campesterol and β-sitosterol) data in this region are also included in the dataset. All biomarkers are based on TOC calculations.

Description: The PIP25 indexes calculated by IP25 and phytoplankton biomarkers (Brassicasterol, Dinosterol, HBI-III) in the East Siberian Sea. The calculation methods based on Mueller et al., 2015.

Description: We provide a dataset of 42 newly collected surface sediment samples from the East Siberian Sea by analysis of Arctic sea ice (IP25) and open water phytoplankton biomarkers (Brassicasterol, Dinosterol, HBI-III and HBI-IV). Terrigenous sterols (campesterol and β-sitosterol) data in this region are also included in the dataset. All biomarkers are based on TOC calculations.

Description: The PIP25 indexes calculated by IP25 and phytoplankton biomarkers (Brassicasterol, Dinosterol, HBI-III) in the East Siberian Sea. To better understand the riverine influence, we compared the data set with and without samples that influenced by riverine input. In this dataset, the estuarine samples (surface salinity 〈 25) are removed. The calculation methods based on Mueller et al., 2015.

Description: We analyzed foraminiferal and nannofossil assemblages and stable isotopes in samples from ODP Hole 807A on the Ontong Java Plateau in order to evaluate productivity and carbonate dissolution cycles over the last 550 kyr (kilo year) in the western equatorial Pacific. Our results indicate that productivity was generally higher in glacials than during interglacials, and gradually increased since MIS 13. Carbonate dissolution was weak in deglacial intervals, but often reached a maximum during interglacial to glacial transitions. Carbonate cycles in the western equatorial Pacific were mainly influenced by changes of deep-water properties rather than by local primary productivity. Fluctuations of the estimated thermocline depth were not related to glacial to interglacial alternations, but changed distinctly at ~280 kyr. Before that time the thermocline was relatively shallow and its depth fluctuated at a comparatively high amplitude and low frequency. After 280 kyr, the thermocline was deeper, and its fluctuations were at lower amplitude and higher frequency. These different patterns in productivity and thermocline variability suggest that thermocline dynamics probably were not a controlling factor of biological productivity in the western equatorial Pacific Ocean. In this region, upwelling, the influx of cool, nutrient-rich waters from the eastern equatorial Pacific or of fresh waters from rivers have probably never been important, and their influence on productivity has been negligible over the studied period. Variations in the inferred productivity in general are well correlated with fluctuations in the eolian flux as recorded in the northwestern Pacific, a proxy for the late Quaternary history of the central East Asian dust flux into the Pacific. Therefore, we suggest that the dust flux from the central East Asian continent may have been an important driver of productivity in the western Pacific.