ECOLOGICAL STUDY OF PICOPLANKTON IN NORTHERN SOUTH CHINA SEA

Abundance, carbon biomass and composition of picoplankton along a transect (fromthe Pearl River estuary to Dongsha Island) in the northern South China Sea were measured by flow cytom-etry (FCM); and the vertical structure, composition variation, relationship between heterotrophic and au-totrophic picoplankton as well as the controlling mechanism of diel variation were studied. Results showedthat along the horizontal direction, both Synechococcus (SYN) and picoeukaryote (PEUK) were highest inabundance and dominated autotrophic picoplankton in the Pearl River estuary, but decreased

Latitudinal and interannual variations of the spring phytoplankton bloom peak in the East Asian marginal seas

Combined studies of latitudinal and interannual variations of annual phytoplankton bloom peak in East Asian marginal seas(17°–58°N, including the northern South China Sea(SCS), Kuroshio waters, the Sea of Japan and the Okhotsk Sea) are rarely. Based on satellite-retrieved ten-year(2003–2012) median timing of the annual Chlorophyll a concentration(Chl a) climax, here we report that this annual spring bloom peak generally delays from the SCS in January to the Okhotsk Sea in June at a rate of(21.20±2.86) km/d(decadal median±SD). Spring bloom is dominant feature of the phytoplankton annual cycle over these regions, except for the SCS which features winter bloom. The fluctuation of the annual peak timing is mainly within ±48 d departured from the decadal median peak date, therefore this period(the decadal median peak date ±48 d) is defined as annual spring bloom period. As sea surface temperature rises, earlier spring bloom peak timing but decreasing averaged Chl a biomass in the spring bloom period due to insufficient light is evident in the Okhotsk Sea from 2003 to 2012. For the rest of three study domains, there are no significant interannual variance trend of the peak timing and the averaged Chl a biomass. Furthermore this change of spring phytoplankton bloom timing and magnitude in the Okhotsk Sea challenges previous prediction that ocean warming would enhance algal productivity at high latitudes.

Single molecular DNA/RNA sequencing with microscopy

Ultra high-throughput DNA sequencing has been a very hot topic beyond the field of genomic researches.There have been various approaches to this issue ranging from direct observation of individual DNA synthesis[1],amperometric/optical detection of bases using a nanopore[2,3]and direct sequencing with a high-resolution probe microscope[4].Recently,we have developed a technique to chemically modify all nucleobases in DNA[5],so that the bases A,T,G,C can be differentiated in the sequence by using high-resolution electron microscopy(EM).