Intraspecific diet shift in Talitrus saltator inhabiting exposed sandy beaches

Talitrid amphipods are the most abundant herbivores on exposed sandy beaches. Despite their important role as trophic intermediates between macrophytes and higher levels (i.e. insect and bird) of beach food webs, very little information is available on their feeding patterns. The main aim of this study was to investigate intraspecific differences in the feeding behaviour of Talitrus saltator. We tested the hypotheses that: (1) adult females and males showed different isotope signatures and therefore relied on different sources of food; and (2) patterns of variation of isotope signatures of juveniles differed from those of adult specimens, evidencing a diet shift during the development. We used stable isotope signatures and tested for differences upon the level on the shore, times of the year and beaches experiencing similar morpho-dynamic and environmental conditions. Finally, we investigated the trophic significance of macrophyte detritus in the diet of males, females and juveniles. Results showed that adult males had a more variable diet than females and juveniles (inferred from δ¹³C and δ¹⁵N values). Dual-isotope graphs suggested that Sargassum muticum and Cystoseira baccata wrack could be among the main food sources for both juvenile and adult stage.     

湖北省能源信息系统的开发与应用

介绍《湖北省能源信息管理系统》以基础地理信息数据“电子地图”为基础,叠加全省能源的现状和规划信息,直观形象地显示我省能源空间分布与特征,实现各类信息的储存、查询、建模、分析、评价等多项功能,提高能源管理水平、应用水平和共享程度。     

东海海水中的溶存甲烷

基于1994年秋季航次在东海的调查资料,较详细地分析了溶存甲烷在水体中的分布规律、成因和来源.表层水中溶存甲烷呈过饱和状态,饱和度127%～254%,温跃层以上水体中,甲烷的断面分布不同于营养盐的分布,各站测值相近,没有显示出受长江冲淡水的影响,而呈现的舌状分布,在陆架底层水中有明显的高浓度甲烷水体,表明甲烷从沉积物中迅速扩散进入底层水.黑潮次表层水的涌升过程稀释了陆架边缘底层水中的甲烷.在陆架和大洋区测站上,甲烷的垂直分布不同,前者主要受物理混合过程所控制;后者呈大洋区分布特征,在温跃层附近出现甲烷的次表层最大,这可能是陆架底层高浓度甲烷沿等密度面的输送所致.     

象山港水体的磷酸盐及其对赤潮的潜在影响

根据2012年5月和2017年10月在象山港海域的调查结果,研究了象山港磷酸盐的来源、分布和消耗。磷酸盐浓度在两次的调查中均呈现由港顶向湾口逐渐降低的趋势,说明港顶区有较高浓度磷酸盐的输入,可能主要来自生活污水和海水养殖。磷酸盐、硝酸盐和盐度在象山港外湾的分布特征说明长江和钱塘江是外湾水体磷酸盐的一个重要来源;此外,磷酸盐、硝酸盐和盐度在牛鼻山水道和佛渡水道的差异分布说明,陆地径流可能经由佛渡水道向象山港贡献了一部分的磷酸盐。内湾水体的磷酸盐分布受控于内外湾水体混合和浮游植物的同化作用,磷酸盐在水体停留时间较长的内湾发生了明显的消耗,相比于保守混合模型的估算值,磷酸盐在象山港内湾中的净消耗比例在2012年5月和2017年10月分别约为20%和9%。2017年秋季观测到的磷酸盐浓度[（1.88±0.31）μmol/L]与2002-2005年在同季节观测到的结果相比增加超过了50%,N/P值下降明显,这一变化可能会导致象山港内引发藻华的藻类种群发生变化,同时也可能会引发更为严重的赤潮。     

Burial fluxes and source apportionment of carbon in culture areas of Sanggou Bay over the past 200 years

In this study,we assessed the burial fluxes and source appointment of different forms of carbon in core sediments collected from culture areas in the Sanggou Bay,and preliminarily analyzed the reasons for the greater proportion of inorganic carbon burial fluxes(BFTIC).The average content of total carbon(TC) in the Sanggou Bay was 2.14%.Total organic carbon(TOC) accounted for a small proportion in TC,more than 65% of which derived from terrigenous organic carbon(Ct),and while the proportion of marine-derived organic carbon(Ca) increased significantly since the beginning of large-scale aquaculture.Total inorganic carbon(TIC) accounted for 60%–75%of TC,an average of which was 60%,with a maximum up to 90% during flourishing periods(1880–1948) of small natural shellfish derived from seashells inorganic carbon(Shell-IC).The TC burial fluxes ranged from 31 g/(m2·a)to 895 g/(m2·a) with an average of 227 g/(m2·a),which was dominated by TIC(about 70%).Shell-IC was the main source of TIC and even TC.As the main food of natural shellfish,biogenic silica(BSi) negatively correlated with BFTIC through affecting shellfish breeding.BFTIC of Sta.S1,influenced greatly by the Yellow Sea Coastal Current,had a certain response to Pacific Decadal Oscillation(PDO) in some specific periods.     

西沙海槽表层沉积物地球化学特征及其地质意义

对西沙海槽区50个表层沉积物的常微量元素进行了地球化学及沉积环境特征研究。西沙海槽区表层沉积物具有SiO2、TiO2含量低和CaO含量高的特征；除了MnO外，各组分的变异系数均较小，元素的分布差异较小，元素分异不明显。常量组分对比表明研究区兼具浅海及深海沉积的特点，为由浅海向深海过渡的半深海沉积环境。富集因子分析表明，从槽坡至槽底富集因子变化不大，略呈增加趋势，Cu、Co、Ni、Pb、Zn、Ba、Mn的富集因子都大于1，表明这些元素除了陆源之外还有其他的来源。海槽区沉积物的化学组分及其来源是复杂多样的，其中包括陆源组分、生物源、火山碎屑等，但陆源碎屑和黏土组分以及碳酸盐型的生物碎屑组分是控制研究区沉积物化学成分的最主要因素。     

Geochemistry and particle size of surface sediments of Gulf of Manfredonia (Southern Adriatic sea)

In this study we describe mechanisms influencing the spatial distribution of the surface sediments in the Gulf of Manfredonia. Seventy-three samples were collected on a regional grid and analyzed for grain-size, major and trace elements and organic matter content. Sediments contain marine-derived carbonate as well as terrigenous fractions indicating highly heterogeneous sediment composition dictated by different provenance and complex transport processes. Principal Component Analysis provides information about processes involved in the formation and dispersal of the sediments. The regional sediment distribution is function of the Gulf's morphology and sedimentary inputs from fluvial sources, mainly from the Ofanto River, and from the North and Central Adriatic basin. Biogenic carbonate reefs, identified in two restricted coastal areas add complexity to sediment shelf dispersal. The North-Adriatic current flowing southward transports and deposits sediments from the Northern basin in the offshore area of the Gulf while an inner anticyclonic current distributes and mixes northern and fluvial sediment with a clockwise pattern. In order to better assess the fluvial contribution also bedload samples from the main river debouching into the Gulf were sampled, enabling the identification of geochemical indexes to distinguish the role of both fluvial inputs and hydrodynamic processes affecting solid particles dispersion within the Gulf. This study provides a contribution to a qualitative estimate of the sediment supply entailed in the Southwestern Adriatic basin.     

Development and application of water environment management information system based on ARCGIS Engine

Embedded ArcGIS Engine can improve development efficiency of environmental information system. The authors designed the structure, functions and database of the Yongjiang River Basin Water Environment Management Information System （YRBWEMIS） through the integration of ArcGIS Engine software with VC. The spatial data and attribute data in the YRBWEMIS are stored and managed separately. The system functions include display, query., statistics, spatial analysis and thematic mapping for water pollution sources, water quality, water function regionalization and catchments region.     

GPS-LEO无线电中性大气掩星反演误差分析

简要介绍GPS-LEO掩星大气反演算法的基本原理,考虑到多种误差源对反演大气参数带来的影响,利用EGOPS仿真模拟软件,采用三维射线追踪法模拟了1 d 内426个掩星事件,并统计分析多种误差源的影响特性。通过反演温度的统计分析发现,现有的卫星钟稳定性以及卫星定轨精度可以满足反演需求;噪声误差对反演影响较大,需要采取有效措施抑制;多路径效应中,周期误差影响较小,但振幅对反演结果有一定影响,需要有效抑制。