Impacts of anthropogenic activities on the Changjiang(Yangtze)estuarine ecosystem(1998–2012)   总被引：1，自引：1，他引：0  

陈东  戴志军  徐韧  李道季  梅学菲 《海洋学报(英文版)》2015,34(6):86-93

Estuarine ecosystem has greatly changed in the recent decades due to anthropogenic perturbations in the Changjiang Estuary. Change patterns and impact factors were analyzed based on the continuous data...  相似文献   

基于生态系统服务的海洋健康评估与调控:以莱州湾为例     

沈程程  郑伟  石洪华  丁德文  王宗灵 《海洋学报(英文版)》2015,34(12):61-66

近岸海域的生态系统管理,要求对海洋健康进行综合的评估以及对人工调控进行科学的指导,进而促进可持续发展。本文构建了定量化方法,用于评估当前的和近期的基于生态系统服务的海洋健康。以莱州湾为例的研究结果表明,当前的海洋健康指数分值为0.7856(总分为1.0);通过对负面压力进行不同强度的人工调控,得到近期海洋健康预计的变化范围为0.5551到0.8041。具体地说,本文评估得到当前的海洋健康主要表现为文化服务和供给服务基本优秀,而支持服务和调节服务不够良好。若不对持续增长的压力采取有效的调控措施,该近岸海域生态系统会在近期丧失部分支持服务和调节服务;若负面压力被完全控制,该近岸海域生态系统服务的分类等级会得到小幅提升。另外,应进一步加强对生态系统服务尤其是文化服务和调节服务的宣传教育。本文的分析过程和量化结果,为进一步指导人工调控提供了灵活的工具,有助于海岸带区域的生态系统管理。  相似文献   

深海内波空间啁啾的演变研究     

孙美玲  王晶  郭凯  张旭东  孟俊敏 《中国海洋大学学报(自然科学版)》2015,45(1):114-120

根据基于两层流体推导的深海内波弱非线性薛定谔(Nonlinear Schrodinger,简称NLS)方程,引进空间啁啾的思想,研究深海区频散效应和非线性效应的作用。文中推导出了频散效应和非线性效应所致啁啾的表达式,采用数值计算方法计算了综合效应产生的总啁啾。分析了频散和非线性以及综合效应所致啁啾在深海内波传播中的演变规律。从空间啁啾的角度,解释中国南海东沙群岛附近深海区内波演变的机理。  相似文献   

山东省滨海湿地生态价值评估     

丁小迪  丁咚  李广雪 《中国海洋大学学报(自然科学版)》2015,45(1):71-75

本文依据Google Earth近2年的遥感影像以及2013年的资源3号卫星影像数据,并结合他人前期研究资料,对山东省滨海湿地的分布和类型进行了研究,使用ArcGIS软件测算出滨海湿地总面积约为5 124km2,其中自然湿地占35.23%,人工湿地占64.77%。根据山东省湿地实际状况,以及湿地的地理位置、成因、水文、生物等要素的差异,将山东省滨海湿地划分为十种类型,并在此基础上,针对滨海湿地不同的生态服务功能类型,采取了不同的方法进行初步价值评估。结果表明,山东省滨海湿地生态服务总价值约3 303亿元,约占山东省2013年GDP的6.04%。其中物质生产价值约占总价值的50.70%,其次为环境调节价值,约占48.24%,社会服务价值只占1.06%。这表明,山东省滨海湿地蕴含较高的经济和生态潜力,能带来较高的经济效益和生态效益,但是社会服务功能价值量相对偏低,有待于进一步重视和开发。  相似文献   

Reef fishes recruited at midwater coral nurseries consume biofouling and reduce cleaning time in Seychelles,Indian Ocean     

S Frias-Torres  H Goehlich  C Reveret  PH Montoya-Maya 《African Journal of Marine Science》2015,37(3):421-426

In coral reef restoration, coral gardening involves rearing coral fragments in underwater nurseries prior to transplantation. These nurseries become fish-aggregating devices and attract biofouling. We hypothesised that: (1) the presence of corals at a nursery is critical to recruit fish assemblages and (2) the recruited fish assemblages control biofouling, reducing person-hours invested in nursery cleaning. Three midwater coral nurseries were deployed at 8?m depth for 27 months within the marine protected area of Cousin Island Special Reserve, Seychelles, Indian Ocean. Each nursery consisted of a 6?m×6?m PVC pipe frame, layered with a recycled 5.5-cm-mesh tuna net. Human cleaning effort was calculated based on daily dive logs. Nursery-associated fish assemblages and behaviour were video-recorded prior to harvesting corals after a 20-month growth period and seven months post-coral harvesting. The density (ind. m–2) of blue-yellow damselfish Pomacentrus caeruleus was 12–16 times higher when corals were present than when corals were absent at the nurseries. Fish assemblages recruited into the nurseries included three trophic levels, from herbivores to omnivores, in six families: Ephippidae, Pomacentridae, Labridae (Scarinae), Gobiidae, Siganidae and Monacanthidae. Higher abundance of large fish (total number of individuals) resulted in 2.75 times less person-hours spent in nursery cleaning. These results have important implications for cost-effective coral reef restoration.  相似文献   

In vitro screening for endocrine disruptive activity in selected South African harbours and river mouths     

JC Truter  JH van Wyk  BK Newman 《African Journal of Marine Science》2015,37(4):567-574

Various waterborne anthropogenic contaminants disrupt the endocrine systems of wildlife and humans, targeting reproductive pathways, among others. Very little is known, however, regarding the occurrence of endocrine disruptive activity in South African freshwater ecosystems, and coastal ecosystems have not been studied in this regard. In a first attempt to investigate endocrine disruptive activity in South African coastal waters, surface water samples collected from harbours, river mouths and estuaries in three metropolitan municipalities, eThekwini (which includes Durban), Nelson Mandela (specifically Port Elizabeth Harbour) and City of Cape Town, were screened for (anti) oestrogenicity and (anti)androgenicity using recombinant yeast bioassays. Moreover, levels of the female hormone 17β-(o)estradiol (E2) were determined in all samples, as well as a selection of hydrocarbons in the eThekwini samples. A high proportion of samples collected from eThekwini were oestrogenic, whereas none from Port Elizabeth Harbour and only a single river mouth sampled in the City of Cape Town were oestrogenic. E2 was detected in all the samples tested, but at higher concentrations at the eThekwini and City of Cape Town localities than Port Elizabeth Harbour. In addition, the recombinant yeast assays revealed that anti-androgenicity was widespread, being detected in the majority of samples screened apart from those representing Port Elizabeth Harbour. Conversely, no anti-oestrogenic or androgenic activity was detected. Anti-androgenicity did not associate with hydrocarbon loads, providing evidence that other anti-androgens were responsible for the observed activity. The present data suggest potential reproductive disruption in marine and estuarine fauna inhabiting the eThekwini and City of Cape Town regions.  相似文献   

基于遥感图像的湿地生态系统健康评价     

何厚军  刘学工  韩琳  陈亮 《测绘工程》2011,20(5):45-48

黄河三角洲湿地是我国暖温带最完整、最广阔、最年轻的湿地生态系统.文中以遥感数据为基础,基于压力一状态一响应框架构建湿地生态系统健康评价指标体系,并运用熵权模糊物元的方法对研究区东营市河口区和垦利县湿地进行评价.研究表明,1997年、2001年、2006年的生态系统健康评价综合得分分别为0.6388、0.7361和0.8...  相似文献   

Net ecosystem metabolism of a coastal embayment fertilised by upwelling and continental runoff     

D. Villegas-Ríos  X.A. Álvarez-Salgado  G. Rosón 《Continental Shelf Research》2011,31(5):400-413

O₂, N, P and Si net ecosystem metabolism of the Ría de Ares-Betanzos (NW Iberian upwelling system) was estimated during two 3-wk periods of contrasting summer downwelling and autumn upwelling conditions by means of a transient 2-D kinematic box model. The subtidal circulation was positive in both situations, although it was depressed during downwelling and enhanced during upwelling. Concurrently, the ría was fertilised mainly by shelf bottom waters, which introduced from 69% (under downwelling) to almost 100% (under upwelling) of the limiting N nutrients. The ría was an efficient nutrient trap: about 70% of the N nutrients that entered the embayment were retained under downwelling conditions (average flushing time, 9 days) and about 50% under upwelling conditions (average flushing time 3 days). Although the trapping efficiency was lower, the net ecosystem production (NEP) was much higher under upwelling (from 1.0±0.3 to 1.5±0.4 g C m⁻² d⁻¹), than under downwelling favourable winds (from 0.2±0.1 to 0.3±0.1 g C m⁻²). The stoichiometry of NEP suggests that P and N compounds recycled faster than C compounds, specially in the inner segment of the ría. The net degree of silification was twice in the inner than in the outer segment of the ría.  相似文献   

湖泊生态系统的水鸟监测意义   总被引：5，自引：3，他引：2  

张淑霞  董云仙  夏峰 《湖泊科学》2011,23(2):155-162

水鸟的多样性及其变化趋势是保护水鸟必需的信息,也是其柄息湿地环境质量的指示因子之一.本文综述了水鸟与湖泊生态系统关系的研究成果,认为水鸟的物种多样性与丰富度可以快速反映湖泊的水生植物、鱼类的生物量和湖泊水位、营养状况的变化,集群繁殖的食鱼水鸟可用于湖泊生态系统中持久性有毒化学污染物的生态监测;同时阐述了水鸟通过取食水生...  相似文献   

基于层次分析法的拉市海高原湿地生态系统健康评估   总被引：1，自引：0，他引：1  

马立广  曹彦荣  李新通 《地球信息科学学报》2011,13(2):234-239

 本文以云南省丽江市拉市海高原湿地生态系统核心区为研究区域,利用区域生态系统功能监测指标和自然环境及人文活动因素指标,对拉市海高原湿地生态系统的健康状况进行空间综合评估分析。首先,根据当前生态系统的状况和高原湿地生态系统的特征,结合湿地保护区开展的系列生态系统功能监测项目及其指标,并充分考虑评估模型的系统性、科学性和实际操作的可行性,构建了拉市海高原湿地生态系统健康评价的指标和指标体系。然后,采用层次分析方法(AHP),融合自然综合指标、人文因素指标在内的生态系统健康综合评价模型,确定6级的生态系统健康评估标准;最后,根据空间评价模型和数据资源,对各个指标权重进行分析计算,得出拉市海高原湿地生态系统的健康状况的空间分布。研究结果表明,拉市海高原湿地的生态系统健康状况良好。按照划定的6级标准,其中,稳定区和较稳定区面积9 358.93hm²,占研究区域总面积的61%,脆弱区和较脆弱区面积为6 058.46hm²,占总面积的39%。整个研究区域内不存在很稳定区和极稳定区,这为高原湿地生态系统的综合管理及发展规划提供了依据。  相似文献