Life history and production of Sphaerium lacustre (Mollusca : Sphaeriidae) in a shallow subtropical Chinese lake

A fingernail clam, Sphaerium lacustre, was studied in subtropical Lake Donghu from June 1999 to May 2000. The S. lacustre population was characterized by a single annual reproduction period starting in March and ending in October; the population comprised three size groups, of which the 1999 cohort was dominant. The annual average density and biomass were 100.2 ind./m(2) and 12.11 g/m(2), respectively The annual production was 43.02 wet weight g/m(2), and the corresponding annual production/biomass ratio was 3.55.

History and variability of Asian interior aridity recorded by eolian flux in the Chinese Loess Plateau during the past 7 Ma

Eolian flux in the Chinese Loess Plateau was reconstructed by measuring the dry bulk density and CaCO3 content of the late Cenozoic loess-paleosol-red clay sequences in the Lingtai profile. Comparison of eolian flux variation between the Lingtai profile and the ODP sites 885/886 in the North Pacific shows a significant wet-dry variability in addition to a gradual drying trend in the dust source regions in interior Asia. Especially, the increase of eolian fluxes from both continental and pelagic eolian sediments indicates a sharp drying of the dust source regions between 3.6 and 2.6 MaBP, which might be attributed to the tectonic uplift of the Tibetan Plateau, which cut down the moisture input to the interior Asia. The average value and variability of eolian flux are higher after 2.6 MaBP than before, which may be related to the Quaternary climatic fluctuations on the glacial-interglacial timescale after the commencement of major Northern Hemisphere Glaciations. The eolian fluxes of the Lingtai profile and Core V21-146 in northwest Pacific show a synchronous variation on the 10(4)-10(5) a timescale, indicating that the flux variations from both continental and marine records are closely correlated to the Quaternary climatic fluctuation forced by the ice volume changes on a global scale.

Origins and pathways of the subsurface and intermediate water masses of the Indonesian Throughflow derived from historical and Argo data

On the basis of Argo data and historic temperature/salinity data from the World Ocean Database 2001 (WOD01 origins and spreading pathways of the subsurface and intermediate water masses in the Indonesian Throughflow (ITF) region were discussed by analyzing distributions of salinity on representative isopycnal layers. Results were shown that, Subsurface water mostly comes from the North Pacific Ocean while the intermediate water originates from both the North and South Pacific Ocean, even possibly from the Indian Ocean. Spreading through tire Sulawesi Sea, the Makassar Strait, and the Flores Sea, the North Pacific subsurface water and the North Pacific Intermediate water dominate the western part of the Indonesian Archipelago. Furthermore its the depth increases, the features of the North Pacific sourced water masses become more obvious. In the eastern part of the waters, high salinity South Pacific subsurface water is blocked by a strong salinity front between Halmahera and New Guinea. Intermediate water in the eastern interior region owns salinity higher than the North Pacific intermediate water and the antarctic intermediate water (AAIW), possibly coming from the vertical mixing between subsurface water and the AAIW from the Pacific Ocean, and possibly coming front the northward extending of the AAIW front the Indian Ocean as well.