[Characterization of Chromophoric dissolved organic matter (CDOM) in Zhoushan fishery using excitation-emission matrix spectroscopy (EEMs) and parallel factor analysis (PARAFAC)].

The composition, distribution characteristics and sources of chromophoric dissolved organic matter(CDOM) in Zhoushan Fishery in spring were evaluated by fluorescence excitation-emission matrix (EEM) combined with parallel factor analysis (EEMs-PARAFAC). Three humic-like components [C1 (330/420 nm)], C2 [(290) 365/440 nm] and C3 [(260) 370/490 nm)] and two protein-like components [C4(285/340 nm) and C5 (270/310 nm)] were identified by EEMs-PARAFAC. The horizontal distribution patterns of the five components were almost the same with only slight differences, showing decreasing trends with increasing distance from shore. In the surface and middle layers, the high value areas were located in the north of Hangzhou Bay estuary and the outlet of Xiazhimen channel, and the former's was higher in the surface layer while the latter's was higher in the middle layer. In the bottom layer, CDOM decreased gradiently from the inshore to offshore, with higher CDOM near Zhoushan Island. The distributions of fluorescence components showed an opposite trend with salinity, and no significant linear relationship with Chl-a concentration was found, which indicated that CDOM in the surface and middle layers were dominated by terrestrial input and human activities of Zhoushan Island and that of the bottom layer was attribute to human activities of Zhoushan Island. The vertical distribution of five fluorescent components along 30.5 degrees N transect showed a decreasing trend from the surface and middle layers to bottom layer with high values in inshore and offshore areas, which were correlated with the lower salinity and higher Chl-a concentration, respectively. On this transect, CDOM was mainly affected by Yangtze River input in coastal area but by bioactivities in offshore waters. Along the 30 degrees N transect, the vertical distribution patterns of CDOM were similar to those of 30.5 degrees N transect but there was a high value area in the bottom layer near the shore, attributing to the CDOM release from the marine sediment pore water to the water body because of physical force role like tidal, the underlying upwelling and so on. A strong correlation occurred between C1 and C3, C4, indicating that they had similar sources; a weak correlation was found between C1 and C2, C5, reflecting some differences among their sources. CDOM in Zhoushan Fishery in spring had low humification index (HIX) values, which reflected a low degree of humification, poor stability and a short resident time in the environment. For biological index (BIX), its higher values appeared in the offshore waters and the lower values occurred in the inshore area, reflecting a greater influence of human and biological activities, respectively.

[Distribution of dissolved inorganic nutrients and dissolved oxygen in the high frequency area of harmful algal blooms in the East China Sea in spring].

According to two cruises in the high frequency area of Harmful Algal Blooms (HABs) in ECS from Apr. 8th to 26th and May 7th to 14th 2010, concentrations and distributions of biogenic elements before and after HABs were analyzed, and their influenced factors were also discussed. The results showed that April was the earlier stage of HAB breaking out, and diatom was the dominant species; while Dinoflagellate became the dominant species when large-scale HAB broke out in May. The concentrations of DIN and PO4(3-) -P decreased significantly from April to May. The Mean value of DIN decreased from 18.04 to 10.80 micromol x L(-1), its decline rate was 40%. As for PO4(3-) -P, its Mean value decreased from 0.47 to 0.27 micromol x L(-1), and its decline rate was 43%. This phenomenon indicated the significant depletion of nutrients by harmful algae in the process. However, the primary species of HABs in ECS was dinoflagellates in May. Since dinoflagellates did not consume SiO3(2-) -Si during the breed, as well as the supplement from Changjiang Diluted Water, the mean value of SiO3(2-) -Si increased slightly from 16. 15 to 16.96 micromol x L(11) in the researched area. The Mean value of DO decreased from 8.76 to 6.09 mg x L(-1) from April to May, because the effect of temperature to DO was more obvious than that of phytoplankton photosynthesis. The temperature was higher in May, and the solubility of oxygen decreased with increasing temperature, therefore, the concentration of DO was lower after the Harmful algal blooms.

[Resolving characteristic of CDOM by excitation-emission matrix spectroscopy combined with parallel factor analysis in the seawater of outer Yangtze Estuary in Autumn in 2010].

The distribution and estuarine behavior of fluorescent components of chromophoric dissolved organic matter in the seawater of outer Yangtze Estuary were determined by fluorescence excitation emission matrix spectra combined with parallel factor analysis. Six individual fluorescent components were identified by PARAFAC models, including three terrestrial humic-like components C1 [330 nm/390(430) nm], C2 (390 nm/480 nm), C3 (360 nm/440 nm), marine biological production component C5 (300 nm/400 nm) and protein-like components C4 (290 nm/350 nm) and C6 (275 nm/300 nm). The results indicated that C1, C2, and C3 showed a conservative mixing behavior in the whole estuarine region, especially in high-salinity region. And the fluorescence intensity proportion of C1 and C3 decreased with increase of salinity and fluorescence intensity proportion of C2 kept constant with increase of salinity in the whole estuarine region. While C4 showed conservative mixing behavior in low-salinity region and non-conservative mixing behavior in high-salinity region, and fluorescence intensity proportion of C4 increased with increase of salinity. However, C5 and C6 showed a non-conservative mixing behavior and fluorescence intensity proportion increased with increase of salinity in high-salinity region. Significantly spatial difference was recorded for CDOM absorption coefficient in the coastal region and in the open water areas with the highest value in coastal region and the lowest value in the open water areas. The scope of absorption coefficient and absorption slope was higher in coastal region than that in the open water areas. Significantly positive correlations were found between CDOM absorption coefficient and the fluorescence intensities of C1, C2, C3, and C4, but no significant correlation was found between C5 and C6, suggesting that the river inputs contributed to the coastal areas, while CDOM in the open water areas was affected by terrestrial inputs and phytoplankton degradation.

[Estimation of the flux of inorganic nitrogen flowing into the East China Sea].

The flux of inorganic nitrogen flowing into the East China Sea was estimated based on the systematic analysis of all the pollution sources from 1980-2005. The result showed that the flux of inorganic nitrogen had been increasing from the early 1980s to the early 21st century. In detail, the flux was about 8.8 x 10(5) t x a(-1) in the early 1980s, and increased to about 2.6 x 10(6) t x a(-1) in the early of 21st century. The annual increasing rate was about 4.3%, and the mean flux was 1.8 x 10(6) t x a(-1). The flux of inorganic nitrogen of Yangtze River had also been increasing from early 1980s to the early 21st century. In detail, the flux was 4.0 x 10(5) t x a(-1) in the early 1980s, and increased to about 6.2 x 10(5) t x a(-1) in the middle 1980s, and was then kept at this value to the end of 1980s. After that, the flux value increased quickly from the early 1990s to 1.8 x 10(6) t x a(-1) in the early 21st century. Of all the sources, the proportion of land-source inorganic nitrogen was the largest, which was about 79%, among which, the river-source, the sewage-source and the non-point source accounted for 73%, 4% and 2%, respectively. Besides the land-source, the air-source and the mariculture-source accounted for 18% and 3%. The proportion of flux of Yangtze River in the river source was 76.5%.

[Distribution of dissolved organic carbon in the Bohai Sea and Yellow Sea in spring].

Based on the data from cruises that carried out in the Yellow Sea and Bohai Sea from April to May, 2010, the horizontal distribution of DOC was studied. And the influencing factors were preliminary discussed. The results showed that the concentration of DOC in the Yellow Sea and Bohai Sea ranged from 0.96 to 4.71 mg x L(-1) in spring and the average content was 2.27 mg x L(-1). In horizontal distribution, the highest DOC content appeared in the coastal zones both in the south and the north and it tended to decrease toward the offshore in central section on the whole. The highest DOC value was in the nearshore in the western of Bohai Sea and eastern of Shandong Peninsula which was mainly affected by the terrestrial inputs and the offshore current, especially in the nearshore of the western of Bohai Sea, the highest DOC content was 4.71 mg x L(-1). The second highest DOC value was in the Northeast of Yangtze River Estuary which was mainly affected by the Yangtze River Diluted Water (YRDW). However, the low DOC content was mainly found in open seas in the central of the South Yellow Sea, and the DOC value was lower than 1.50 mg x L(-1).

[Temporal and spatial distribution of particulate organic carbon in the Yellow Sea and East China Sea in spring].

Based on the data from cruises that carried out in the Yellow Sea and East China Sea from April to May, 2009, the temporal and spatial distributions of the particulate organic carbon (POC) were analyzed. And the sources of POC were further discussed according to the chlorophyll a (Chl-a) and C/N. The results showed that the concentration of POC in the Yellow Sea and East China Sea ranged from 24.33 microg/L to 2 817.29 microg/L in spring and the average content was 230.76 microg/L. In horizontal distribution, the highest POC content is in the coastal zones and it tends to decrease toward the far shore on the whole. The highest concentration of POC appears at the northern of Jiangsu Province coastal waters both in surface layer and bottom layer in particular, which is mainly affected by resuspension of sediments. And there is also a second highest concentration in the vicinity of the Yangtze River estuary, indicating the primary influence in the Yangtze River is by diluted water. The concentration of POC in shallow sea area is the highest and distributed uniformly and it is primarily from terrestrial inputs and resuspension. Moreover, the resuspension is relatively stronger than terrestrial inputs. However, the POC concentration in far coast deep water area is under 75 microg/L and it reduces gradually with the increase of water depth, which shows ocean water characteristics. And the POC is mainly from the ocean. The diurnal change of POC concentration in the middle of East Sea shows half-cycle variation, as a whole, the concentration value is high both in the afternoon and midnight, while it is relatively low at dusk, which is mainly under the influence of biological activity at the scene.

Molecular cloning, in vitro expression and bioactivity of quail BAFF.

B cell activating factor (BAFF), belonging to the TNF (tumor necrosis factor) family, is critical for B cell survival and maturation. In the present study, a quail BAFF cDNA, named qBAFF, was amplified from quail spleen by RT-PCR and RACE (rapid amplification of cDNA ends) strategies. The open reading frame (ORF) of qBAFF cDNA encodes a protein consisting of 288-amino acid. The deduced amino acid sequence contains a predicted transmembrane domain and a putative furin protease cleavage site like other identified BAFF homologues. The qBAFF shows 96, 93, 93, 53 and 51% amino acid sequence identity with chicken (cBAFF), goose (gBAFF), duck (dBAFF), human (hBAFF) and mouse BAFF (mBAFF), respectively, with the functional soluble parts of qBAFF is 98, 99, 98, 78 and 71%, respectively. RT-PCR showed that BAFF is expressed in many tissues in the quail, including bursa, spleen, liver, brain, heart, intestine, kidney, thymus and muscle. Recombinant soluble qBAFF (qsBAFF) fused with His(6) tag was efficiently expressed in Escherichia coli BL21 (DE3) and its molecular weight of approximately 19kDa was identified by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) and Western blotting. In vitro, purified qsBAFF was able to promote the survival of quail bursa B cells. Our results suggest that qBAFF plays an important role in survival of quail B cells cultured in vitro.

[Effects of irradiance on blooms of the dinoflagellate Prorocentrum donghaiense Lu in the coastal area in East China Sea].

With field culture experiments and model calculations, the natural-light-dependent growth and the optimal light layers in sea water for growth of red tide dinoflagellate Prorocentrum donghaiense Lu were studied in order to analyze the role of light on algal blooms in the coastal area in East China Sea in spring. The results show that the relationship of growth and light can be well described by Steele's equation, and the optimal light intensity (Iopt) of P. donghaiense is (38.2 +/- 3.8) W x m(-2), which is lower than Iopt for several other red tide algae (40-133 W x m(-2)), meaning that P. donghaiense may have an advantage when developing blooms in turbid environments where solar irradiance is easily attenuated. The optimal light layers for P. donghaiense growth are thicker offshore than inshore, and the thickness of optimal light layers in the subsurface water usually in 3-15 m in depth is about 5-10 m in the red tide area. The trade-off of light and nutrient fitness results in blooms in the so-called red tide area, and the light-optimum characteristic of the subsurface water is an important factor for the subsurface bloom development in spring.

[Exchange rates of dissolved nutrients at the sediment-water interface before and after diatom bloom in the East China Sea in spring].

Exchange rates of dissolved nutrients at the sediment-water interface were studied before and after diatom bloom from March to May in the East China Sea in 2005. Intact sediment cores which were sampled at 10 sites were incubated on board, and exchange rates were calculated in the function method. It was shown that sediment absorbed NO3(-) -N before bloom with the exchange rate ranging from - 1.33 mmol/(m2 d) to - 0.68 mmol/(m2 d). The sediment released NO3(-) -N after bloom with the exchange rate ranging from - 0.69 mmol/( m2 d) to 0.82 mmol/( m2 d). NH4(+) -N was almost released from sediment with the exchange rate ranging from -0.65 mmol/(m d) to 1.46 mmol/( m2 d), and the rate was higher before bloom than that after bloom. NO2(-) -N moved into sediment all along except at Zc17 with the exchange rate ranging from - 0.09 mmol/(m2 d) to 0.05 mmol/(m2 d), and the rate was a little higher after bloom than that before bloom. SiO3(2-) -Si was released from sediment all the time with the exchange rate ranging from 0.85 mmol/(m d) to 9.23 mmol/( m2 d), and the rate was higher after bloom than that before bloom. The sediment absorbed PO4(3-) -P before bloom with the exchange rate ranging from -0.06 mmol/(m2 d) to -0.01 mmol/(m2 d), but released PO4(3-) -P after bloom with the exchange rate ranging from 0 mmol/(m2 d) to 1.26 mmol/(m2 d). PO4(3-) -P and NO3(-) -N which were absorbed by sediment in spring restricted the diatom bloom, but their release from sediment after diatom bloom may make a great contribution to subsequent dinoflagellate bloom.

[Discrimination of Red Tide algae by fluorescence spectra and principle component analysis].

Fluorescence discrimination technology for 11 species of the Red Tide algae at genus level was constructed by principle component analysis and non-negative least squares. Rayleigh and Raman scattering peaks of 3D fluorescence spectra were eliminated by Delaunay triangulation method. According to the results of Fisher linear discrimination, the first principle component score and the second component score of 3D fluorescence spectra were chosen as discriminant feature and the feature base was established. The 11 algae species were tested, and more than 85% samples were accurately determinated, especially for Prorocentrum donghaiense, Skeletonema costatum, Gymnodinium sp., which have frequently brought Red tide in the East China Sea. More than 95% samples were right discriminated. The results showed that the genus discriminant feature of 3D fluorescence spectra of Red Tide algae given by principle component analysis could work well.

[Seasonal variation and spatial distribution of nutrients and their relationships with harmful algal blooms in coastal area of the East China Sea].

Based on the data from four cruises that carried out in the Changjiang River estuary and its adjacent areas from 2002-04 to 2003-02, the seasonal variation and spatial distribution of nutrients were analyzed, and the relationship between nutrients condition and the harmful algal blooms (HABs) was also discussed. Results showed that the annual average concentration of nutrient was (17.93 +/- 2.46) micromol x L(-1) for DIN, (0.59 +/- 0.11) micromol x L(-1) for PO4(3-) -P, (15.34 +/- 3.23) micromol x L(-1) for SiO3(2-) -Si, and the study area was in the state of eutrophication. The average concentration of nutrient showed a remarkable seasonal fluctuation with the higher value in autumn and winter and lower value in spring and summer. The spatial distribution of the nutrients was typically such that the concentrations of DIN, PO4(3-) -P and SiO3(2-) -Si decreased from inshore to offshore area, and the contours generally decreased rapidly in down-coast directions. DIN and SiO3(2-) -Si of the study area were largely contributed by Changjiang River diluted water and other terrigenous inputs, while PO4(3-) -P mainly by Changjiang River diluted water and the Taiwan Warm Current. The following HABs showed that its occurrences were usually laid in the areas with higher nutrients and lower total suspended particles (TSP).