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Enteromorpha prolifera (E. prolifera) tides have erupted frequently in the Yellow Sea and brought serious environmental problems to coastal sea since 2007. In order to research the influence of nutrients on E. prolifera growth, mesocosm experiments were carried out in the Yellow Sea in May 2012. There were 12 mesocosms, including 9 different experimental conditions. It shows that the uptake ability of nutrients and the growth of E. prolifera are strong. The growth rate of E. prolifera reaches 82% when the nutrient level is appropriate, while the rate could also keep around 10% even under low nutrient conditions. When phosphate level is appropriate, high dissolved inorganic nitrogen (DIN) concentration could promote the growth of E. prolifera. Sufficient and continuous nutrient supplement is the material basis for outbreak of E. prolifera green tide. Through analyzing the amount of nutrient uptake by E. prolifera, the production of organics by photosynthesis could be estimated, which has a strong linear relationship with the increased of wet weight of E. prolifera.

PAHs were measured by gas chromatography-mass spectrometry (GC-MS) in the surface sediments collected from the southern Shandong Peninsula coastal area. Contents and distribution characterizations of PAHs, PCBs and OCPs in the area were discussed. The concentration of PAHs in the surface sediments decreased gradually from the inshore area to the offshore area. According to the ratio of P/A and Fl/Py, the release from combustion of fuel was one of the most major sources of PAHs in this area. The level of PCBs in the surface sediments was higher in the Jiaozhou Bay and southwest coast of Qingtao, and lower in the other area. The distribution of PCBs decreased gradually from the inshore to the offshore area. OCPs in surface sediments also decreased from the inshore to the offshore area. The HCHs data showed the area was polluted by agriculture and industry at the same time. There were only a few DDTs imported into the area in the recent years, and DDTs were decomposed by aerobic microbial degradation in surface sediment. The concentration of PAHs, PCBs and OCPs suggested that the potential risk of environmental pollution was low in the area.

The 31 wet deposition samples were collected at Chongming Island from June 2004 to May 2005 in the Yangtze Estuary, and dissolved species of nutrients (NH4+, NO3-, NO2-, PO4(3-) and SiO3(2-)) in the rainwater were analyzed by Spectrophotometry. The results showed that there were significant differences among monthly average concentration of nutrient elements, and the nitrogen content in the rainwater was rather high. The wet deposition flux was 52.02 mmol/(m2 x a) for the total inorganic nitrogen (TIN), 0.17 mmol/(m2 x a) for phosphate and 0.10 mmol/(m2 x a) for silicate. The wet deposition fluxes for TIN were larger than that for PO4(3-) and SiO3(2-). NH4+ was the dominant form of TIN, occupying 70.9% of TIN. The proportion of nutrients in the wet deposition and seawater had obvious differences. The rainwater can change the nutrients structure, salinity, pH, phytoplankton production and biologic community in the surface seawater, and this phenomenon may lead to the red tide directly.

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.

The three-dimensional fluorescence of dissolved organic matter in the mesocosm with different nutrients enrichment experiments in Jiaozhou Bay was determined by using excitation-emission matrix spectrum. The result indicates that phytoplankton can produce protein-like and humic-like fluorescent matter. The protein-like fluorescence is composed of tyrosine-like fluorescence and tryptophan-like fluorescence. The main position of protein-like fluorescent peak is Ex(max)/Em(max) = 270 nm/290 - 310 nm. The fluorescent intensity of the peak located in Ex(max/ Em(max) = 270 - 290 nm/320 - 350 nm is less. The centers of humic-like peaks disperse at Ex(max)/Em(max) = 250 - 260 nm/380 - 480 nm (Peak A), Ex(max)/Em(max) = 310 - 320 nm/380 - 420 nm(Peak C) and Ex(max)/Em(max) = 330 - 350 nm/420 - 480 nm(Peak M) in which peak A is the main peak. The fluorescent intensity of tyrosine-like matter is stronger than the intensity of humic-like matter. When the amount of phytoplankton decreased, the fluorescent intensity of tyrosine-like matter has negative relativity with the chlorophyll-a concentration. Tyrosine-like matter and tryptophan-like matter have similar origin. Dinoflagellate can produce more protein-like fluorescent matter than diatom. The composition ratios of humic-like mixture are different in different environment. And it has a small A/C value in dinoflagellate environment compared to diatom environment.

Fluorescence excitation-emission matrix spectroscopy was employed to characterize the change of humic-like fluorescence from Dagu River to Jiaozhou Bay. The relationships of humic-like fluorescence characteristics with salinity, pH, chlorophyll a, dissolved organic carbon, chemical oxygen demand and carbohydrate were discussed. The results show that humic-like fluorescence intensities are high in Dagu River but low in Jiaozhou Bay. The input of Dagu River is important origin of humic-like fluorescent dissolved organic matter of Jiaozhou Bay. High humic-like fluorescence intensity and high chlorophyll a are not coexist always, which suggests that humic-like fluorescent dissolved organic matter doesn't mainly come from phytoplankton. Good relationships of humic-like fluorescence intensity with dissolved organic carbon, chemical organic demand and carbohydrate suggest that humic-like fluorescent matter is the main component of dissolved organic matter. The distribution of humic-like fluorescence reflects the distribution of dissolved organic matter to some extents.

Fluorescence excitation-emission matrix spectroscopy (EEMS) was employed to characterize the dissolved organic matter (DOM) in algal bloom seawater of Jiaozhou Bay in February, 2004. The relationships of DOM fluorescence characteristics with phytoplankton multiplication, dissolved organic carbon (DOC), salinity, dissolved oxygen and pH were discussed. In addition, the protein-like and humic-like fluorescence changes fore and aft cross-flow ultrafiltration (CFF) were primarily evaluated. The results show that the intensities of high and low-excitation protein-like fluorescence, which have the same sources, are stronger than that of humic-like during algal bloom. Both correlations between protein-like fluorescence intensities and chlorophyll-a and between humic-like fluorescence intensities and chlorophyll-a are relevant to the phytoplankton multiplication. As a whole, the fluorescence intensities of protein-like and humic-like increases with chlorophyll-a increasing. Furthermore the ratios of new to old DOM increase with phytoplankton biomass increasing. Good positive correlations between protein-like fluorescence intensities and DOC and between the ratios of protein-like to humic-like fluorescence intensities and DOC suggest that the DOC is mainly composed of newly produced matter during algal bloom. Some inorganic factors, such as salinity, dissolved oxygen and pH, have little effects on protein-like and humic-like fluorescence. Fore and aft the CFF experiments, the positions of protein-like and humic-like fluorescence peaks have little alteration, the balance of fluorescence intensity is not so good as organic carbon mass balance as a whole. Fluorescence balance should be used only as a supplementary technique for evaluating contaminations or loss by organic carbon mass balance.