热带印度-太平洋浮游有孔虫Pulleniatina obliquiloculata的B/Ca和Cd/Ca指标：次表层海水碳化学参数计算的应用

Pulleniatina obliquiloculata shells from 16 core-top samples from the tropical Indo-Pacific Oceans are analyzed for the ratios of boron and cadmium to calcium(B/Ca and Cd/Ca). The B/Ca ratios show a very weak positive relationship with [B(OH)_4~-] and the dissolved carbonate species at the apparent calcification depth of P.obliquiloculata. The boron partition coefficients(K_D) between P. obliquiloculata B/Ca and seawater[B(OH)_4~-]/[HCO_3~-] distribute around 1.1×10~(-3)-1.3×10~(-3) with a mean value of(1.19±0.12)×10~(-3),and are significantly related to the nutrient concentration, especially phosphate. The lack of any clear correlation between the P. obliquiloculata B/Ca and seawater carbonate chemical parameters suggests that the physiochemical controls on boron incorporation are masked by the complexity of natural seawater condition. But the significant dependence of Ku on nutrient may likely be explained by a nutrient related growth-rate effect. Cd/Ca of P.obliquiloculata shows significant correlation with seawater phosphate concentration, and its partition coefficients(D_(cd)) are significantly related to temperature. A first-principle methodology of P. obliquiloculata B/Ca is applied;with the aid of Cd/Ca as a phosphate proxy and a constraint on K_D, to estimating sea water carbonate chemistry(e.g., pH). The results are fairly promising and allow us to propose the possibility to apply the combination of B/Ca and Cd/Ca proxies(and also Mg/Ca and δ~(18)O for estimating temperature and salinity) for the paleoreconstruction of seawater carbonate chemistry.     

绿色渔业背景下的舟山群岛新区海洋渔业创新发展

为促进舟山群岛新区海洋渔业经济发展水平的进一步提升,文章以绿色渔业为背景,采用PEST分析法综述舟山群岛新区海洋渔业创新发展的宏观环境和存在的问题,并提出措施建议。研究结果表明:舟山群岛新区海洋渔业创新发展具有优良的政治、经济、社会和技术环境,但存在渔业资源环境约束、渔业经营规模小、休闲渔业同质化和现代技术发展受阻等问题。未来舟山群岛新区海洋渔业创新发展应主要采取4项措施:加强海域资源环境修复,建设海洋牧场;提升海洋渔业信息化水平,建设渔业智库;深入挖掘旅游文化资源,打造特色休闲渔业综合体;推进互联网技术运用,开拓"互联网+海洋捕捞业"新模式。     

鄱阳湖流域饶河龙口入湖段优势淡水鱼类对微塑料及重金属污染物的生物累积

水体生态环境中的微塑料与重金属污染问题正日益受到热切关注为探讨微塑料与重金属对水产品的复合生态效应,选择鄱阳湖饶河段优势淡水鱼为研究对象,对鱼体内微塑料及重金属Cu、Cd、Pb、Zn、Cr等元素的生物累积作用进行分析与评价结果表明:调查区域水环境中微塑料的丰度范围10～64 items/L,平均值38.56 items/L. 8种淡水鱼消化道微塑料丰度范围为1.21～9.11 items/g,平均丰度为5.40 items/g;鳃部丰度范围0.61～5.00 items/g,平均丰度为2.87 items/g;微塑料类型主要有碎片类、纤维类、薄膜类和颗粒类4种,其聚合物成分主要为聚乙烯(PE)、低密度聚乙烯(LDPE)、聚丙烯(PP)和聚苯乙烯(PS);颜色以透明及彩色为主;微塑料粒径范围为0.01～9.5 mm,粒径0.5 mm的微塑料所占比例为79.07%,鱼体内与其生存水环境中微塑料的丰度特征(形态、粒径、颜色和聚合物类型组分比例)具有一定相似性各鱼类对微塑料的累积系数(BAF)平均值为178.29,不同鱼类累积微塑料的能力大小次序为:乌鳢(Channa argus)、黄颡鱼(Pelteobagrus fulvidraco)鲦鱼(Hemicculter leuciclus)、草鱼(Ctenopharyngodon idellus)、鲶鱼(Silurus asotus)鲤鱼(Cyprinus carpio)、刀鱼(Coilia ectenes)、鲫鱼(Carassius auratus)鱼体肌肉组织内重金属Cu、Cd、Pb、Zn、Cr的平均含量分别为4.27、0.13、0.28、11.73、0.53 mg/kg,均符合无公害水产品的要求且低于人体消费卫生标准,属于安全食用范围;鱼类对5种不同重金属的累积能力大小次序为ZnCuCdPbCr,不同鱼类对不同重金属的累积能力具有差异性通过扫描电镜(SEM)与能谱分析(EDS)检测到各类型微塑料表面均有上述5种重金属元素,证实微塑料可能成为重金属的附着载体,相关性分析表明微塑料与Cu呈极显著相关,与Cd、Pb均呈显著相关;微塑料的存在一定程度上会增强Cu、Cd与Pb的累积效应,并可能产生复合污染效应.     

Changing structure of benthic foraminiferal communities due to declining p H: Results from laboratory culture experiments

The ocean absorbs large amounts of CO_2 emitted from human activities, which results in a decrease in seawater p H.Marine calcifying organisms such as foraminifera, are most likely to be affected by this declining pH. In this study, we collected sediments from five stations of different depths(34–73 m) in a continental shelf of the Yellow Sea. The entire benthic foraminiferal communities together with sea sediments were cultured under three constant pHs(8.3, 7.8, and 7.3) for 6 and 12 weeks in the laboratory to study their responses to pH or incubation time. The microcosm's experimental results obtained showed that most of the foraminiferal community parameters(abundance, species richness, Margalef index, and Shannon-Wiener diversity) decreased significantly(p<0.05) with the decline in pH in all the tested stations. The responses of foraminifera to the decline in p H were species-specific, for instance, Protelphidium tuberculatum and Cribroelphidiumfrigidum were highly sensitive to declining pH and were finally eliminated at low pH, while some species(e.g., Lagenammina atlantica, Verneuilinulla advena, V. propinqua, Haplophragmoides applanata, and H. canariensis) could tolerate low pH and acted as pH-tolerant species. In addition, the proportion of hyaline taxa showed a significant(p<0.05) positive correlation with pH, while agglutinated type showed a negative response. Furthermore, different incubation times(6 and 12 weeks) showed significant effects on the nearshore communities other than the offshore treatments, which were, however, entirely declined after 6 weeks' incubation under low p H manipulation. Our results indicated that nearshore foraminiferal communities showed rather a resilience to the declining p H and the offshore foraminifera, especially those in the central area of the Yellow Sea Cold Water Mass were found to be more sensitive to the decline in pH in the continental shelf sediments of the Yellow Sea.     

西北农居震害构成及抗震性能综合影响因素分析

整理西北地区部分地震的震害资料,对西北五省的主要农居进行震害总结,分析不同结构农居震害和抗震性能,发现不同结构的抗震性能差别较大,并针对不同结构提出相应的防震减灾措施。从地震动特性、场地和地基基础、结构的自身特性等方面分析影响农居民房的抗震能力,并根据西北农居震害特点给出了防震减灾方面的一些建议。     

四种浸提剂对果园与菜地土壤有效硒浸提效果的对比研究

有效硒是评价土壤中硒对植物供给能力的重要指标,我国目前尚无测试有效硒的国家标准方法。浸提剂的选择对于准确测定有效硒的含量至关重要,本文根据浸提的有效硒与硒形态的关联性来确定最优浸提剂种类。实验中选取了碳酸氢钠、磷酸二氢钾、硝酸和盐酸四种浸提剂,对天津果园和菜地的土壤进行有效硒浸提,采用原子荧光光谱法测定各形态硒的含量,并分别对浸提的有效硒与水溶态+离子交换态+碳酸盐结合态硒的最小值、25%处数据值、中位数、75%处数据值和最大值进行比较分析和差异性检验。结果表明:采用碳酸氢钠和磷酸二氢钾提取菜地土壤有效硒的平均含量均约为0.039mg/kg,高于硝酸和盐酸的提取量;采用碳酸氢钠、磷酸二氢钾、硝酸和盐酸提取果园土壤有效硒的含量依次降低。两种土壤中,磷酸二氢钾浸提有效硒的最小值、25%处数据值、中位数、75%处数据值和最大值与水溶态+离子交换态+碳酸盐结合态硒的含量最为接近,而且无显著差异性。研究认为,0.1mol/L磷酸二氢钾适合作为天津果园和菜地土壤有效硒的浸提剂。     

结合随机森林面向对象的森林资源分类

针对森林资源分类研究较少且缺少相对简单有效的方法的情况,提出一种结合面向对象和随机森林的森林资源分类方法。面向对象分割技术可减少“椒盐效应”,随机森林分类算法具有高准确度、抗噪声能力强、性能稳定等优势。鉴于此,通过调整面向对象的分割参数,构造最优特征空间及估算随机森林中决策树的数量等,构建了最优的面向对象随机森林分类模型。另外,选择了SVM算法作对比试验。试验结果显示,本文分类算法的总体精度达到83.34%,Kappa系数为0.7892,明显高于SVM,能够有效提高森林资源分类的精度。     

我国主要海洋捕捞政策对浙江省海洋捕捞业的影响探究

随着海洋渔业资源的不断衰退,为了保护渔业资源、推动海洋渔业的可持续发展,自20世纪70年代后期,我国出台了许多海洋捕捞相关政策。文章从投入控制制度、产出控制制度和技术控制制度3个角度出发,以捕捞许可制度、捕捞限额管理和伏季休渔制度等政策为重点,通过整理1980—2017年浙江省渔业经济的相关资料,从海洋捕捞渔船数量和功率、海洋捕捞产量、渔业劳动力数量变化3个方面,深入分析浙江省海洋捕捞现状,提出了完善现有的海洋捕捞政策、加强渔业执法管理力量、加强普法宣传、建立渔业资源调查与评估体系、帮助捕捞从业人员转产转业等对策建议,以期为我国海洋捕捞管理部门提供决策参考。     

南海西北部89PC柱样沉积物中浮游有孔虫特征及其古环境意义

对南海北部89PC柱状样进行了浮游有孔虫定量统计分析、氧碳同位素测试、碳酸钙含量分析和AMS14C测年,并采用古生态转换函数计算了表层海水古温度和温跃层深度,揭示了该海区约127 ka以来的古海洋学特征。温跃层转换函数计算的温跃层深度结果表明,在MIS5-MIS4期,温跃层深度没有大的变化,在MIS3-MIS1期,温跃层的深度逐渐变深。古温度转换函数计算的古温度结果表明,夏季温度的变化范围为27.9~29.3℃,变化幅度为1.4℃,冬季温度变化范围为20.6~26.3℃,变化幅度为5.7℃。与南海南部的冬夏古水温资料进行对比,南海南部的温度比南海北部的温度要高,这种差异在冬季时表现更为突出,且在冰期时南海南部和北部的温度差异梯度进一步增大,指示了冰期时冬季风更加强盛。     

一株海水氨氧化细菌的系统发育分析

应用PCR技术扩增16S rRNA基因和amoA(ammonia monooxygenase subunit A)的基因片段,并测定其序列,对一株源于海水养殖水体的高效氨氧化细菌(ammonia-oxidizing bacteria,AOB)进行了系统发育分析。结果表明,经PCR扩增得到了1 098 bp的16S rRNA基因片段和491 bp的amoA基因片段,将其序列用NCBI-Blast软件在GenBank数据库中进行同源性检索后发现,该菌株的16S rRNA基因序列和amoA基因序列分别与亚硝化单胞菌Nitrosomonas sp.NS20的相对应基因片段相似性分别为98.4%和96.7%。在此基础上构建了系统发育树,表明用该菌株的16S rRNA基因片段和amoA基因片段构建的系统发育树均与亚硝化单胞菌属类聚在一起,结合该菌株形态和生理生化特性,鉴定该株氨氧化细菌属亚硝化单胞菌。