西瓦湖中壬基酚和双酚A的污染特征

本文研究了西瓦湖内外各环境介质 ,包括表层水体、悬浮物、间隙水和沉积物中的壬基酚和双酚 A的浓度分布。结果表明 ,湖内上述介质中的壬基酚浓度分别为 1 7.4～ 1 1 3.4 ng/ L ,1 5 .6～ 2 8.6 ng/ L,2 4 0～ 3890 ng/ L和 5 .6～ 1 6 2 9ng/ g,西瓦湖外的壬基酚浓度则相对较低。表层水体与其他介质中的壬基酚浓度之间存在显著性相关关系。双酚 A的分布特征与壬基酚相似 ,但前者的浓度较低 ,在上述介质中的浓度分别为 1 3.0～ 5 0 .4 ng/ L,3.2～ 8.5 ng/ L,85～ 2 80 ng/ L和 1 .3～1 1 .2 ng/ g。本文还讨论了西瓦湖中的壬基酚和双酚 A污染对当地生物的潜在危害     

我国近岸海域富营养化评价新方法及应用

参考目前国际上被广泛应用的第2代富营养化评价方法体系,结合我国近岸海域生态环境特点和监测资料现状,建立了一种以压力-状态-响应模式为基本框架、以富营养化症状为主的第2代近岸海域富营养化评价体系。实际应用结果表明,应用本方法得出的长江口海域富营养化状况评价结论,与目前国外主流评价方法的评价结论一致,而且本方法具有评价指标代表性强、数据资料易得、评价标准有据、方法简便易行等优点。     

我国近岸海域富营养化评价新方法及应用

参考目前国际上被广泛应用的第2代富营养化评价方法体系,结合我国近岸海域生态环境特点和监测资料现状,建立了一种以压力-状态-响应模式为基本框架、以富营养化症状为主的第2代近岸海域富营养化评价体系。实际应用结果表明,应用本方法得出的长江口海域富营养化状况评价结论,与目前国外主流评价方法的评价结论一致,而且本方法具有评价指标代表性强、数据资料易得、评价标准有据、方法简便易行等优点。     

Characteristics and landcover of estuarine boundaries: implications for the delineation of the South African estuarine functional zone

This study investigated whether the current lateral boundary for estuaries in South Africa, i.e. the estuarine functional zone (EFZ), includes all estuarine habitats. The EFZ covers 173 930 ha in 304 estuaries/outlets nationally. Field surveys and analysis of available aerial images showed that 82 (12 956.70 ha) of these estuaries (26%) had estuarine habitats occurring outside of this boundary. As a result of mapping scale, the National Vegetation Map does not represent habitats that are associated with small estuaries (approximately 50% of South Africa's estuaries). For estuaries in the Western and Eastern Cape provinces, most habitats have been lost due to urban development, whereas in subtropical areas (northern Eastern Cape and KwaZulu-Natal), cultivation has removed estuarine habitat. Although delineation of boundaries can be complicated by landcover changes, the estuarine lateral boundary in Cape estuaries could be identified based on sediment characteristics (moisture content, organic content, electrical conductivity), groundwater characteristics (salinity, conductivity and depth) and plant species. The delineation of the EFZ needs to be consistent, inclusive of all estuarine physical and biological processes, and cost-effective to identify so that it can protect estuarine habitats.     

河口和沿岸海域生态环境质量综合评价方法评介

海洋环境管理从以往单纯的海洋污染管理已发展到当前的海洋生态环境综合管理。相应地,海洋环境质量评价也从以往单一的污染状况评价(包括水质、沉积物和生物体)发展到海洋生态环境质量综合评价。重点介绍了2种有代表性并被广泛应用的河口和沿岸海域生态环境质量综合评价方法———欧盟的“生态状况评价综合方法”和美国的“沿岸海域状况综合评价”。比较和评析了2种方法的异同和优缺点。建议尽快建立适合中国河口和沿岸海域特点的海洋生态环境质量综合评价方法以及相应的监测和管理体系。     

我国滨海湿地生态修复领域规范的现状与分析

滨海湿地是地球上十分重要的一类生态系统, 可为人类社会提供诸如调节气候、降解污染、碳汇氮汇等众多生态服务功能。近年来, 由于气候变化和围填海等开发活动的影响, 我国滨海湿地面积锐减, 功能退化, 面临多种生态问题。为应对滨海湿地退化及日益凸显的生态环境问题, 滨海湿地保护和修复工作逐渐受到重视, 滨海湿地生态修复工程项目的数量和规模也随之急剧增加。滨海湿地生态修复技术规范对滨海湿地生态修复工作具有重要意义, 然而我国滨海湿地生态修复领域规范体系尚不完善, 导致滨海湿地生态修复项目实施无序以及生态修复成效低等问题。本文全面搜集了我国滨海湿地生态修复领域规范, 对检索到的规范进行分类统计与分析, 从而揭示其存在的问题, 主要包括规范体系系统性不足、生态修复理念滞后、规范之间缺乏协调性、规范可操作性差、规范更新迟滞等。针对存在的问题提出了相应的对策建议, 为完善我国滨海湿地生态修复领域规范体系、不断推进我国生态文明建设进程提供参考。     

闽江河口表层沉积物重矿物特征与物源示踪

对闽江河口近岸海域的230个表层沉积物样品和闽江20个表层沉积物样品进行重矿物分析,系统地研究了重矿物的分布特征及其物源指示。研究区共鉴定出重矿物27种,主要以普通角闪石、绿帘石、磁铁矿和黑云母为主。根据重矿物组合分布特征,将研究区分为两个矿物组合区,并划分为3个矿物组合亚区。闽江口近岸沉积区(Ⅰ-1区)矿物组合为普通角闪石-磁铁矿-绿帘石,受闽江物质影响很大;近岸混合沉积区(Ⅰ-2区)矿物组合为普通角闪石-磁铁矿-黑云母-绿帘石,受浙闽沿岸流携带物质和闽江物质共同影响沉积形成,闽江物质影响明显减弱;残留沉积区(Ⅱ区)矿物组合为普通角闪石-绿帘石-磁铁矿,主要为受后期改造的晚更新世海侵边界层。     

近50年来莱州湾南岸气候变化及环境效应

利用实测的地面气象资料,对近50年来莱州湾南岸的气候变化特征进行了分析。发现自1954年以来莱州湾南岸地区气温持续升高;年均降雨量处于波状起伏状态,1970年以前为多雨期,1970-1990年为少雨期,此后降雨量又有所增加。气温和降水量的变化,加上人类活动不断增强,导致莱州湾南岸海水入侵快速发展,台风风暴潮发生频次和强度有所增加,滨海生态系统发生变化。     

Petroleum pollution in surface sediments of Daya Bay,South China,revealed by chemical fingerprinting of aliphatic and alicyclic hydrocarbons

Nine surface sediments collected from Daya Bay have been Soxhlet-extracted with 2:1 (v/v) dichloromethane-methanol. The non-aromatic hydrocarbon (NAH) fraction of solvent extractable organic matter (EOM) and some bulk geochemical parameters have been analyzed to determine petroleum pollution of the bay. The NAH content varies from 32 to 276 μg g⁻¹ (average 104 μg g⁻¹) dry sediment and accounts for 5.8–64.1% (average 41.6%) of the EOM. n-Alkanes with carbon number ranging from 15 to 35 are identified to be derived from both biogenic and petrogenic sources in varying proportions. The contribution of marine authigenic input to the sedimentary n-alkanes is lower than the allochthonous input based on the average n-C₃₁/n-C₁₉ alkane ratio. 25.6–46.5% of the n-alkanes, with a mean of 35.6%, are contributed by vascular plant wax. Results of unresolved complex mixture, isoprenoid hydrocarbons, hopanes and steranes also suggest possible petroleum contamination. There is strong evidence of a common petroleum contamination source in the bay.     

Investigation and comparison of one-dimensional (1-D) analytical models prediction for salt intrusion condition in two selected estuaries

Abstract

In this paper, two analytical models used worldwide to assess salinity variation in alluvial estuaries are applied to the Ashtamudi estuary, a Ramsar site, southwest coast of India; and Bouregreg estuary, in northwest part of Morocco. The estuaries’ bathymetry is described by an exponential function. Both models are quite similar and use a predictive equation for the dispersion in the estuary mouth (D₀). The major difference between the two models is the use of the constant value of K?=?0.5 for the Van der Burgh coefficient (K) and the introduction of the correction factor ζ, which is a function of damping (δ) and shape (γ). The performance of these two models was evaluated by comparing their results with field measurements; this revealed that both analytical models apply well to both the estimation of salinity distribution and the prediction of salt intrusion in the Ashtamudi and Bouregreg estuaries (Ashtamudi: RMSE = 0.60–1.22 ppt; Bouregreg: RMSE = 0.92–2.71 ppt). One model agrees more with the field measurements of salinity distribution along the estuaries axis; the second underestimate and overestimate some values of salinity distribution along the estuaries. Possibly, the constant value of K?=?0.5 for the Van der Burgh coefficient (K) has applicability limits for the estuaries under tidal conditions. The specifying of the parameterization may be a field of research.     

Nitrite-induced enhancement of toxicity of phenanthrene in fish and its implications for coastal waters

Coastal areas are prone to varying degrees of anthropogenic chemical contamination. In many coastal environments experiencing reducing conditions in the water column, nitrite is produced as a result of denitrification. With a view to determining the effect of a natural stress such as the presence of nitrite in water on the xenobiotic metabolism in fish, the euryhaline cichlid Oreochromis mossambicus was exposed for up to 9 days to environmentally relevant concentrations of water-borne nitrite and phenanthrene, a polycyclic aromatic hydrocarbon.Analyses of different biomarkers in the treated fish indicated significant increase in the metabolism of phenanthrene as a result of exposure to nitrite. For example, the activity of the biotransformation enzyme measured as 7-ethoxyresorufin-O-deethylase activity was, in the presence of 1 μM nitrite, nearly twice that produced by phenanthrene alone. Similarly, biliary fixed fluorescence values reflecting phenanthrene and its metabolites were rendered 1.7 times higher when exposed simultaneously to nitrite. Contact with nitrite and phenanthrene together also led to severe hepatic damage with possible cell death as inferred from the large enhancement in sorbitol dehydrogenase activity in the serum and reduced liver somatic index.     

南海区重点岸段海岸侵蚀现状成因分析与防治对策

在2003年与2006年对南海区琼州海峡两岸重点岸段(雷州市徐闻县龙塘镇赤坎村岸段、海南省海口市镇海村岸段和新海村岸段)的海岸侵蚀进行了现场监测,测量了侵蚀的长度、宽度和面积。对两年现场测量结果进行比较分析,结果表明:海岸侵蚀长度的平均速度为200m/a,宽度的平均速度为20m/a,面积的平均速度为4000m2/a。应用了地质分析、水动力分析、极端海洋气候影响分析等新的理论和方法重点分析了海岸侵蚀的成因,并提出了一些对策,供相关部门参考。     

Tributyl tin levels for sea water,sediment, and selected marine species in coastal Northland and Auckland,New Zealand

Water and sediment samples were collected from the Waitemata Harbour, Opua Inlet, and Tutukaka Harbour, and analysed for tributyl tin (TBT) using a hydride generation atomic absorption method. Specimens of oysters (Crassostrea gigas, Saccostrea glomerata, Ostrea heffordi) and oyster borer, Lepsiella scobina, were collected from the Tamaki Estuary and surrounding areas. These specimens were analysed for TBT using graphite furnace atomic absorption, and the oyster shell valves were examined for thickening. Concentrations of TBT in the water column were as high as 0.32 μg TBT‐Sn H. Marina sediments contained up to 0.240 μg TBT‐Sn g^‐1. Shell thickening was found to occur in C. gigas where its incidence was correlated with the TBT body burden. Concentrations up to 2.24 μg TBT‐Sn gr^‐1 (on a dry weight basis) were observed for C. gigas. This survey provides evidence for the toxic influence of TBT on non‐target organisms in New Zealand.     

Repeat photography as a tool for detecting and monitoring historical changes in South African coastal habitats

Repeat photography was used to illustrate long-term changes occurring in coastal habitats in the Western Cape, South Africa. Historic images were sourced from books and theses, the public and subject specialists, and repeat photographs were then taken from the same perspectives. Visible changes could be categorised into four types: (1) changes in species’ ranges; (2) biological invasions; (3) sea level changes; and (4) direct engineering impacts. In terms of range changes, the images depict a progressive easterly spread of the cold-water kelp Ecklonia maxima and parallel easterly contraction of the warmer-water mussel Perna perna, both evidence for declining water temperatures along the South-West Coast. Since c. 1980 most shores have also become conspicuously invaded by the alien Mediterranean mussel Mytilus galloprovincialis, while those on the West Coast have also been visibly invaded by the more-recently introduced Pacific barnacle Balanus glandula. No changes in vertical zonation due to changing sea levels could be detected, despite suitable images being available. Construction along the shore has radically altered the appearance of the shoreline in urban areas. Repeat photography thus proved a useful tool for both detecting and dramatically illustrating historic changes over the past century. These changes have altered substantially both the appearance and ecological attributes of many rocky shores in this region.     

Changes to regulations and the gear used in the South African commercial fishery for Jasus lalandii

Alterations to the operational fishing gear used in the South African west coast rock lobster Jasus lalandii fishery and their resultant impacts are investigated. The most important developments have been: (i) a change during the 1960s from hand-hauled hoopnets to winch-hauled traps, with a concomitant modification of vessels; (ii) the introduction of deck-grid sorters in 1975; (iii) an increase during 1984 of minimum mesh aperture from 62 to 100 mm (stretched), with a concomitant decrease in the length of the trap codend; (iv) a decrease in the minimum legal size during the early 1990s; and (v) the introduction of bottom-grid traps in 1994. Most of these alterations have been driven by a trade off between the need for greater operational efficiency and concerns surrounding the issue of how best to deal with the problem of catching and releasing specimens smaller than the minimum legal size.     

The importance of estuary head waters as nursery areas for young estuary- and marine-spawned fishes in temperate South Africa

The restriction of freshwater flow into estuaries, the presence of in-stream barriers and the occurrence of invasive fish species in these habitats are identified as major threats to these young estuary- and marine-spawned fish species. These aspects have been investigated using the distribution and abundance of young estuary- and marine-spawned fish species in the headwater environments of four permanently open estuaries of the Eastern Cape, South Africa. Fishes were collected twice per season over the 2009 and 2010 period, using mixed method sampling with seine net hauls and overnight fyke net deployments. Of the 74,751 fishes collected, 37,444 fishes, 18 families and 34 species were taken in fyke net catches, while 34,308 fishes, 21 families and 38 species were caught in seine nets. In the Great Fish, Kowie, Kariega and Sundays River systems, juveniles of estuarine residents dominated headwater catches, followed by juveniles of estuary-dependent marine species. The prevalence of larval and small juvenile stages of estuary- and marine-spawned fish species highlights the potential importance of these transitional areas for young fish.     

The East Caledonian Current: A Case Example for the Intercomparison between AltiKa and In Situ Measurements in a Boundary Current

This paper presents an assessment of SARAL/AltiKa satellite altimeter for the monitoring of a tropical western boundary current in the south-western Pacific Ocean: the East Caledonian Current. We compare surface geostrophic current estimates obtained from two versions of AltiKa along-track sea level height (AVISO 1 Hz and PEACHI 40 Hz) with two kinds of dedicated in situ datasets harvested along the satellite ground tracks: one deep-ocean current-meter mooring deployed in the core of the boundary current and five glider transects. It is concluded that the AltiKa-derived current successfully captures the velocity of the boundary current, with a standard error of 11 cm/s with respect to the in situ data. It also appears important to reference AltiKa sea level anomaly to the latest mean dynamic topography available in our area. Doing so, Ka-band altimetry provides a satisfactory representation of the western boundary current. Thereby, it usefully contributes to observing its variability in such a remote and under-observed ocean region. However, the rather long repeat period of SARAL (35 days) in comparison to the high frequency variability seen in the flow velocity of the boundary current calls for a combined use of SARAL with the other satellite altimetry missions.     

Revised estimates of abundance of South African sardine and anchovy from acoustic surveys adjusting for echosounder saturation in earlier surveys and attenuation effects for sardine

Hydro-acoustic surveys have been used to provide annual estimates of May recruitment and November spawner biomass of the South African sardine Sardinops sagax and anchovy Engraulis encrasicolus resources since 1984. These time-series of abundance estimates form the backbone of the assessment of these resources, and consequently the management of the South African sardine and anchovy is critically dependent on them. Upgrades to survey equipment over time have resulted in recent surveys providing more accurate estimates of abundance, yet in order to maintain comparability across the full time-series, estimates of biomass mimicking the old equipment were used for a number of years. In this paper we develop a method to revise the earlier part of the time-series to correct for receiver saturation in the older generation SIMRAD EK400 and EKS-38 echo sounders and to account for attenuation in dense sardine schools. This is applied to provide a revised time-series of biomass estimates for the South African sardine and anchovy resources with associated variance–covariance matrices. Furthermore, the time-series presented here are based on updated acoustic target strength estimates, making this the most reliable time-series currently available for both resources.