Summer distribution and geochemical composition of suspended-particulate matter in the east china sea

The distribution and geochemical composition of suspended-particulate matter (SPM) in the East China Sea (ECS) were investigated during the summer period of high continental runoff to elucidate SPM sources, distribution and cross-shelf transport. The spatial variability of SPM distribution (0.3–6.5 mg l⁻¹) and geochemical composition (POC, Al, Si, Fe, Mn, Ca, Mg and K) in the ECS was pronounced during summer when the continental fluxes of freshwater and terrestrial materials were highest during the year. Under the influences of Changjiang runoff, Kuroshio intrusion, surface production and bottom resuspension, the distribution generally showed strong gradients decreasing seaward for both biogenic and lithogenic materials. Particulate organic carbon was enriched in surface water (mean ∼18%) due to the influence of biological productivity, and was diluted by resuspended and/or laterally-transported materials in bottom water (mean 9.4%). The abundance of lithogenic elements (Al, Si, Fe, Mn) increased toward the bottom, and the distribution correlations were highly significant. Particulate CaCO₃ distribution provided evidence that the SPM of the bottom water in the northern part of the study area was likely mixed with sediments originally derived from Huanghe. A distinct benthic nepheloid layer (BNL) was present in all seaward transects of the ECS shelf. Sediment resuspension may be caused by tidal fluctuation and other forcing and be regarded as the principal agent in the formation of BNL. This BNL was likely responsible for the transport of biogenic and lithogenic particles across or along the ECS shelf. Total inventories of SPM, POC and PN are 46, 2.8 and 0.4 Tg, respectively, measured over the total area of 0.45 × 10⁶ km² of the ECS shelf. Their mean residence times are about 27, 13 and 11 days, respectively. The inventory of SPM in the water column was higher in the northernmost and southernmost transects and lower in the middle transects, reflecting the influences of terrestrial inputs from Changjiang and/or resuspended materials from Huanghe deposits in the north and perhaps from Minjiang and/or Taiwan’s rivers in the south. The distribution and transport patterns of SPM and geochemical elements strongly indicate that continental sources and cross-shelf transport modulate ECS particulate matter in summer.     

Using benthic macrofauna to assess environmental quality of four intertidal mudflats in Hong Kong and Shenzhen Coast

Abstract-Intertidal zone is a significant wetland between land and ocean. It plays an important rolein maintaining local ecological balance. Both Mai Po and Futian intertidal mudflats are located in Shen-zhen Bay and are important "refueling" point along the East Asian/Australian flyway of migratory birds.The environmental quality of Mai Po and Futian mudflats have aroused great concern due to rapid eco-nomic developments in Hong Kong and Shenzhen in recent decades. Microinfauna of Mai Po and Futianmudflats was investigated in December 2000 and the faunal data were used to assess their environmentalquality. Two other mudflats, namely Ma Wan Typhoon Shelter (a more disturbed area) and Luk Kengintertidal mudflat (a place with relatively less human disturbance), were also sampled for macroinfaunaand used as reference mudflats. Shannon-Weaver species diversity index (I_(sd)), biotic coefficient (C_b)and macrofaunal pollution index (I_(mp)) of the macrofauna community on four intertidal mudflats wereused to     

假晴东方鲀人工育苗研究

假晴东方鲀人工育苗获得４１．８ｍｍ种苗３５１０００尾，每立方水体出 苗８６０尾。越冬成活率９１．６％，增重率６１．８％。利用室内水泥池及养虾土池 养成商品鱼，分别获得１９６９ ｇ／ｍ３和 ２０８ ｋｇ／亩的收成。     

海洋沉积物中的氮循环

氮(N)是生物生命活动的基本营养元素，N循环是整个生物圈物质和能量循环的重要组成部分。近几十年来，环境和资源问题的日益突出促进了人们对海洋生态系统的研究及对海洋资源的开发和利用，海洋中的N循环亦受到了广泛关注。尤其是20世纪90年代以来，随着国际地圈与生物圈计划(IGBP)、全球海洋通量联合研究(JGOFS)、全球海洋生态系统动力学研究(GLOBEC)等重大国际合作计划的实施，海洋中的N循环研究取得了重大进展。 本文主要对海洋沉积物中的N循环过程进行了阐述，包括海洋沉积物中N的生物地球化学循环(海洋中N与生物生产过程的关系、早期成岩作用及N的去营养化、沉积物中N循环及其控制机制、颗粒N的形成及其功能、N与其他生源要素循环的关系)及沉积物中N循环的研究方法等，以期对进一步开展N循环的研究有所帮助。     

台湾海峡西岸第四纪沉积层中的老红砂

本文对采自福建沿海的老红砂作了粒度分析、矿物鉴定和石英电镜扫描。结果表明,组成老红砂的成分主要为中细砂,砂含量大于70%,粘土和粉砂含量较少。概率累积曲线多为跳跃、悬浮两段式,其次为滚动、跳跃、悬浮三段式。轻矿物以石英为主,长石含量居次。含量较高的重矿物有磁铁矿、钛铁矿、白钛石,其次有锆石、赤铁矿、褐铁矿、电气石、绿帘石等。文章对老红砂的成因提出一些粗浅的看法。     

海洋褐藻胶生产废水的絮凝-氧化处理研究

使用新型高效的絮凝剂Xp，对海洋褐藻胶生产废水进行絮凝，催化氧化处理试验，确定了絮凝剂Xp的最佳使用条件，催化氧化时间和氧化剂用量，结果表明，经本工艺处理后，废水中主要污染物CODcr的去除率达到83．9％，处理后的废水基本达到国家《污水综合排放标准》（GB8978－1996）限定的二级标准。     

一种提高粘土矿物去除赤潮生物能力的新方法

在研究粘土颗粒与赤潮生物絮凝作用的基础上，建立了粘土表面改性对其絮凝作用影响的理论模型，认为改变粘土颗粒的表面性质提高其去除赤潮生物能力的主要途径，提出在粘土中引入ＰＡＣＳ（聚羟基氯化铝）的改性方法。结果表明，对于微型原甲藻（Ｐｒｏｒｏ－ｃｅｎｔｒｕｍ ｍｉｎｉｍｕｎ）体系，粘土中引入微量ＰＡＣＳ后，其去除率达９０％以上的高岭土用量由原来的２ｇ／Ｌ降至０．１ｇ／Ｌ，去除效率提高近２０倍。考察了ＰＡ     

长江口南港水道潮流特征分析

根据１９９６年长江口南港水道枯、丰水期（１月、７月）大、中、小潮两次各２６ｈ以上的全潮水文实测资料,统计分析了实测流的特征和潮流类型、运动形式、潮流垂直变化、余流、Ｍ２分潮流及分潮流对涨、落潮流不等的影响。     

粘土矿物对海水中主要营养盐的吸附研究

对海水中磷盐和硝酸盐在粘土矿物上的吸附行为的研究发现，海水体系中高岭土对磷酸盐的吸附能力大于蒙脱土，其原因为，粘土颗粒的表层铝／硅结构比是控制磷酸盐吸附的主要因素，其中铝含量越高，肿附能力越大。考察ＰＨ、粘土酸改性处理等因素对吸附作用的影响，结果表明，ＰＨ＜８．５的磷酸盐吸附ＰＨ曲线呈峰形，其吸附作用以阴离子交换为主；ＰＨ＞８．５时磷酸盐的吸附作用以沉淀吸附为主。酸改性蒙脱土可提高吸附磷酸盐的能力