Effects of an artificial oyster shell reef on macrobenthic communities in Rongcheng Bay,East China

An artificial oyster shell reef was deployed in Rongcheng Bay, East China. However, the effects of this reef on the surrounding macrobenthic communities were unknown. We compared sedimentary factors, macrobenthic biomass, abundance, and community composition and ecological indicators between the reef and non-reef areas over a one year period. The mean values for chlorophyll a （Chl a）, total organic matter （TOM）, total organic carbon （TOC）, and total nitrogen （TN） content in surface sediments in the reef area were slightly higher than those in the non-reef area. The Chl a levels differed significantly between the two areas, but the TOM, TOC, and TN were not significantly different. The abundance of crustaceans was significantly different between the two areas, but the abundance and biomass ofpolychaetes, echinoderms, mollusk did not differ significantly. The permutational multivariate analysis of variance （PERMANOVA） revealed that the macrobenthic community differed significantly through time and analysis of similarity multivariate analyses （ANOSIM） revealed that the macrobenthic community differed significantly in some months. The ecological indicators revealed that the environmental quality of the reef area was slightly better than that of the non-reef area. Overall, our results suggest that the artificial oyster shell reef may change the macrobenthic community and the quality of the environment. Despite the lack of an effect in the short term, long-term monitoring is still needed to evaluate the effects of artificial oyster shell reefs on macrobenthic communities.     

VERTICAL PROFII,ES OF CHL-A AND PRIMARY PRODUCTIVITY IN THE MIDDLE CONTINENTAL SHELF AREA AND EDDY AREA OF THE EAST CHINA SEA

Vertical profiles of chl-a and primary productivity in the middle continental shelf area and eddy area of the East China Sea were studied using data from a cruise in the East China Sea in February to March, 1997 and a cruise in July, 1998. The results showed that chl-a vertical distribution closely related to in situ hydrological and nutrient conditions. Chla-a concentration ranged from 0.22 to 0.35 mg/m³ and 0.93–1.09 mg/m³ in the eddy area and in the middle continental shelf area, respectively. In both areas, chl-a concentrations in deep layers were slightly higher than those in shallow layers, but was of the same order of magnitude. In summer, when a thermocline existed in the water column, highest chl-a concentrations appeared at the base of the thermocline layers in both areas. In the eddy area, chl-a concentration maximized at 31.743 mg/m³, and averaged 1.143 mg/m³ below 30 m depth. In the middle continental shelf area, the highest chl-a concentration was 2.120 mg/m³, the average was 1.168 mg/m³. The primary productivity reached 1418.76 mgC/(m²·d) in summer and 1360.69 mgC/(m²·d) in winter. In the eddy area, the primary productivity was 787.50 mgC/(m²·d) in summer and 159.04 mgC/(m²·d) in winter. Vertical carbon sinking rate from the deep layer to the bottom in both areas is also discussed in this paper. Contribution NO. 4183 from the Institute of Oceanology, Chinese Academy of Sciences. Project No. 49636210 supported by NSFC.     

��ظ�ԭ���������쳣�ĵ����춯��ѧ�о�

???????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????о??????? ????????????????????????????????б?′?????????????????????????????????????????????????     

HVF������GPS��·��ЧӦ�о��е�Ӧ��

????????Helmert????????????Vondrak????????????HVF??????????????GPS??·??Ч????о????????????????????????????÷???????????Vondrak?????????????????????????????????Ч????????????????е????????????????÷????????·????????????GPS??·??Ч?????????????????????Ч????????·??Ч??????????????????GPS??λ?????     

�ֽ�ؿ��˶�����ѧ����״̬������Ԥ�����о�

??????????????????????????о????40????????????????????α估GPS????????????????????????????????????????????????????????????????????????????????????????￡????????????????????????????????????????????????????????????????????????????????????????????????????????????顢???塢???????????,????????????????????????????????????????????????????1??????????????????????????????????????????????????????????????????????鵽????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????SOC??????????????????????????????????????????????????????????????????????е?????????     

Study on changes of plasmalemma permeability and some primary inorganic ions of Antarctic ice microalgae （Chlamydomonas sp. ICE-L） in the low-temperature stress

The changes of plasmalemma permeability and some primary inorganic ions of Antarctic ice microalgae （ Chlamydomonas sp. ICE-L） in the low-temperature stress were examined. The plasmalemma of 1CE-L could maintain the stability at the freezing condition of -6 ℃. That signifies that it could maintain the proper function of plasmalemma and stability of the intracellular environment during sea ice formation. The function of inorganic ions on low-temperature adaptation of ICE-L was investigated by using the X-ray microanalysis method. Low temperature （0 - -6 ℃ ） induces Ca^2 ＋ concentration increment of cytoplasm, but after 24 h the content decrease quickly to normal value. As a matter of fact, Ca^2 ＋ plays an important role as the second messenger in the low temperature adaptation of ICE-L. In addition, low temperature also influences on the other primary inorganic ions transfer and the cell maintains activity by keeping ratio balance among different ions. Above all, it is necessary for Antarctic ice microalgae to survive and breed by maintaining the stability of K^ ＋ content and the balance of Na^ ＋/Cl^ -.     

Identification and characterization of endosymbiosis-related immune genes in deep-sea mussels Gigantidas platifrons

Deep-sea mussels of the subfamily Bathymodiolinae are common and numerically dominant species widely distributed in cold seeps and hydrothermal vents.During long-time evolution,deep-sea mussels have evolved to be well adapted to the local environment of cold seeps and hydrothermal vents by various ways,especially by establishing endosymbiosis with chemotrophic bacteria.However,biological processes underlying the establishment and maintenance of symbiosis between host mussels and symbionts are largely unclear.In the present study,Gigantidasplatifrons genes possibly involved in the symbio sis with methane oxidation symbionts were identified and characterized by Lipopoly saccharide(LPS) pull-down and in situ hybridization.Five immune related proteins including Toll-like receptor 2(TLR2),integrin,vacuolar sorting protein(VSP),matrix metalloproteinase 1(MMP1),and leucine-rich repeat(LRR-1) were identified by LPS pull-down assay.These five proteins were all conserved in either molecular sequences or functional domains and known to be key molecules in host immune recognition,phagocyto sis,and ly so some-mediated digestion.Furthermore,in situ hybridization of LRR-1,TLR2 and VSP genes was conducted to investigate their expression patterns in gill tissues of G.platifrons.Consequently,LRR-1,TLR2,and VSP genes were found expressed exclusively in the bacteriocytes of G.platifrons.Therefore,it was suggested that TLR2,integrin,VSP,MMP1,and LRR-1 might be crucial molecules in the symbiosis between G.platifrons and methane oxidation bacteria by participating in symbio sis-related immune processes.     

藻类功能食品的物质基础与研究开发现状

对藻类功能食品的研究和开发现状作综述报道。涉及的主要内容有：作为功能食品物质基础的食物纤维、ＰＵＦＡ、维生素、矿物质和微量元素、氨基酸以及其它有生理活性的物质。     

光释光测年揭示浑善达克沙地中世纪暖期和小冰期环境变迁与人类活动的关系

为了深入了解中世纪暖期和小冰期浑善达克沙地环境变迁与人类活动的关系,对沙地5个具有代表性的风成砂——砂质土剖面序列进行了光释光测年研究。结合粒度、磁化率、烧失量等气候替代性指标及地层中的文化遗存分析,得到了浑善达克沙地近2ka来的环境变迁记录: 距今1.45~1.10ka和0.83~0.58ka,浑善达克沙地发育砂质土层,气候温暖湿润,与中国唐朝暖期和元朝暖期相对应,欧洲此时经历了中世纪暖期,该地自然环境条件比较优越,旱作农业文化发展。距今1.10~0.83ka和0.58~0.20ka,浑善达克沙地发育浅黄色砂层,气候干旱寒冷,沙丘活化,分别与我国宋辽和清朝冷期相对应,其中宋辽冷期是中世纪暖期的气候波动,清朝冷期则对应于欧洲小冰期,游牧文化发展。浑善达克沙地地层序列、气候替代性指标及其所保存的人类文化遗存揭示了自然环境与人类活动的相互关系。2ka以来,气候经历了暖湿与冷干的交替变化,自然环境变化影响了人类生产生活方式。沙地气候事件可能对我国相应时期朝代的兴亡产生过重大影响。     

从碱湖沉积和孢粉组合看内蒙古伊盟地区近5ka以来的古植被古气候变迁

内蒙古伊盟地区哈马尔太碱湖沉积特征和孢粉组合特征反映了该区近５ｋａ以来的古植被古气候变迁。研究表明，此期间该区植被由阔叶、灌木草原变为疏树灌木草原，最后变为荒漠草原。在这５ｋａ中存在两次暖期两次冷期，近１．６ｋａ以来以冷干为主。湿润气候只存在于４．５～５．５ｋａＢ．Ｐ．，气候总的趋势是由较湿润变干旱直至干燥。