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1.
For hundreds of years, the seas have been used as a place to dispose of wastes from human activities. Although no high level radioactive waste has been disposed of into the sea, variable amounts of packaged low level radioactive wastes have been dumped at 47 sites in the northern part of the Atlantic and Pacific Oceans. in 1946 the first sea dumping operation took place at a site in the North-East Pacific Ocean. the last dumping operation was in 1982, at a site off the European continental shelf in the Atlantic Ocean. Between these two dates, an estimated 46 PBq (1.24 MCi) of radioactive waste coming from research, medical, military and industrial activities have been disposed of at sea. the present trend, through the Convention for the Prevention of Marine Pollution by Dumping of Wastes and other Matter and other Regional Conventions, points towards the prohibition of the dumping of any radioactive waste into the marine environment.  相似文献   
2.
The feasibility of using U.K. coal-fired power station waste materials for artificial reef production is being examined. in June, 1989, an experimental artificial reef was constructed in Poole Bay, off the central south coast of the U.K., using three different mixtures of pulverised fuel ash (PFA), flue gas desulphurisation (FGD) gypsum and slurry, stabilized with cement and formed into blocks. Fifty tonnes of 40 × 20 × 20 cm blocks were formed into eight conical reef units replicating three different PFA/gypsum mixtures and one concrete control. the reef structure is 10m below chart datum on a flat sandy sea-bed.

Combustion of coal concentrates the heavy metal content in the resultant ash. the purpose of stabilization of the ash as blocks is twofold: to immobilize heavy metals (or other components) and to provide hard substratum for the attachment of organisms. to examine the effectiveness of this stabilization and hence the environmental compatibility of the block materials, heavy metal (Cd, Cr, Cu, Pb, Mn, Ni, Zn) content of the blocks has been monitored routinely over two years, to determine leaching rates. Sectional profiles indicate partial replacement of calcium content by magnesium. Associated with this there has also been some redistribution of heavy metals. Only in the case of cadmium has there been a detectable loss from the surface of blocks. Chromium and manganese concentrations appear to have increased. the metal content of the reef epibiota (including ascidians, Ascidia mentula; hydroids, Halecium spp.; bryozoans, Bugula spp. and red algae) growing on the ash blocks has been compared to that of epibiota attached to the concrete controls and surrounding sea-bed. to date no evidence of excess bioaccumulation of metals has been detected.

The physical integrity of the ash reef blocks has been maintained. There is evidence that the blocks are increasing in compressive strength.

An indication of the fishery enhancement potential of the experimental structure is given by the presence of eight commercially fished species (crustaceans and molluscs) including lobsters (Homarus gammarus).  相似文献   
3.
基于经过验证的三维水动力-水质模型,对珠江口夏季有机碳进行海陆源区分,并对海陆源有机碳的分布特征、贡献比重及其通量过程进行研究.结果表明,水平方向上,珠江口夏季陆源(海源)有机碳浓度从口门到外海逐渐降低(升高),在表、底层海水中平均浓度分别为1.45和0.87mg/L(0.97和1.05mg/L);垂直方向上,在层化水域陆源(海源)有机碳浓度从上到下逐渐递减(升高),在非层化水域海陆源有机碳浓度垂向分布较为均匀.珠江口夏季海源有机碳贡献率表层海水低于底层海水,平均贡献率为48.26%,沿向海方向海源有机碳贡献率逐渐增加--从内伶仃洋水域的4.43%逐渐提升到外伶仃洋东侧水域的81.20%.珠江口水动力条件复杂,在径流、潮汐、季风等因素的作用下陆源有机碳向海输送且向海输送量逐渐递减;海源有机碳在不同水域动力输送特征不同,西南水域向海输送,向海输送量逐渐递增;东北水域向岸输送,向岸输送量逐渐递减.陆源有机碳生化反应活性较弱,只有小部分被生化过程消耗,其迁移转化主要由沉降过程控制,而海源有机碳的迁移转化,则由口门的动力输送过程主控向外海的生化耗碳过程主控过渡.此外,海源有机碳沉降作用明显低于陆源有机碳,生化作用明显高于陆源有机碳.  相似文献   
4.
中国沿海省市海洋生态补偿效率评价   总被引:2,自引:0,他引:2  
本文运用考虑非期望产出的超效率SBM模型、DEA-Malmquist指数模型、Tobit模型和标准差椭圆模型,对2006-2016年中国11个沿海省市的海洋生态补偿效率开展测度和分析,结果显示:2006~2016年中国总体海洋生态补偿效率平均值为0.633,处于中等效率水平,随时间呈“下降-上升-稳定”的趋势;海洋生态技术进步依旧是海洋生态补偿过程中全要素生产率的重要驱动力,但面临一定的技术效率损失;海洋第三产业比重对海洋生态补偿效率值有正向的显著影响,城市化率、进出口总额占比和海洋灾害直接经济损失对海洋生态补偿效率存在显著的负向影响;海洋生态补偿效率的空间聚集性增强,区域不平衡性有所收敛,空间分布格局基本保持稳定.  相似文献   
5.
以海洋环境中一个非常重要的局部腐蚀形式——低水位加速腐蚀(ALWC)为对象,自其检测、发生原因、防护三个方面就国内外的文献报告进行综述分析。在检测方面,首先介绍了常用的宏观观察这一被动形式,并突出其特征,然后介绍了利用海水中可溶性无机氮含量作为ALWC发生概率预测这一主动形式,分析其优势与不足。在发生原因方面,在对将ALWC认定为一种典型的微生物腐蚀(MIC)形式的认知过程进行介绍之后,重点分析了微生物对ALWC作用机制不清晰的原因,并建议在后续研究中突出动态演变过程,结合高通量测序等分子生物学技术,确定在不同的阶段影响ALWC的关键微生物,且进一步在大气-海水体系下研究典型菌株及其协同作用的影响,提出微生物对ALWC的作用机制。在防护方面,根据新建和已建钢结构设施分别对传统和针对ALWC所具有的MIC与局部腐蚀特性的新型高效防护方法进行了介绍,并分析了防护方法的优缺点。  相似文献   
6.
The REEF Fish Survey Project is a volunteer fish monitoring program developed by the Reef Environmental Education Foundation (REEF). REEF volunteers collect fish distribution and abundance data using a standardized visual method during regular diving and snorkeling activities. Survey data are recorded on preprinted data sheets that are returned to REEF and optically digitized. Data are housed in a publicly accessible database on REEF's Web site (http: //www.reef.org). Since the project's inception in 1993, over 40,000 surveys have been conducted in the coastal waters of North America, tropical western Atlantic, Gulf of California and Hawaii. The Fish Survey Project has been incorporated into existing monitoring programs through partnerships with government agencies, scientists, conservation organizations, and private institutions. REEF's partners benefit from the educational value and increased stewardship resulting from volunteer data collection. Applications of the data include an evaluation of fish/habitat interactions in the Florida Keys National Marine Sanctuary, the development of a multi-species trend analysis method to identify sites of management concern, assessment of the current distribution of species, status reports on fish assemblages of marine parks, and the evaluation of no-take zones in the Florida Keys. REEF's collaboration with a variety of partners, combined with the Fish Survey Project's standardized census method and database management system, has resulted in a successful citizen science monitoring program.  相似文献   
7.
8.
Concentrations of HCB, DDTs and PCBs in the tissues andorgans of cetaceans ( Stenella coeruleoalba, Tursiops truncatus, Balaenoptera physalus, Steno bredanensis}, Grampus griseus} and Globicephala melaena) strandedalong the Italian coasts in the period 1987–1993 are reported. The values are compared between speciesand between specimens of the samespecies. Chlorinated hydrocarbon (CH) levels were found toincrease in relation to the quantity andtype of lipids in each tissue and organ. Differences inaccumulation encountered in the differentspecies are principally due to different feeding habitats.Remarkable differences found between malesand females of each species confirm that during gestation andlactation, females undergo disintoxication by passing much of their total burden of CHs to their young.  相似文献   
9.
对2003年7月15~9月28日间中国第二次北极科学考察沿线所采集的气溶胶样品进行分析,获得了Na 、NH4 、K 、Mg2 、Ca2 、Cl-、MSA、SO2-4、NO3-、C2O2-4和CH3COO-11种离子的浓度.离子组成表明,气溶胶主要以海盐颗粒为主,其中(Na Cl-)的贡献平均为60.2%;其次为硫酸盐.根据因子分析,11种离子归为4个因子,解释方差为83.7%.因子1包括Na 、nss-Mg2 、nss-Ca2 、Cl-和nss-SO2-4,代表陆地和海洋混合源,解释方差为41.2%;因子2包括NH 4、nss-K 和NO3-,来源于化石燃料燃烧和生物质燃烧所释放的二次污染物,解释方差为18.9%;因子3只有MSA,来源于海洋表层浮游植物排放的二甲基硫(DMS)的氧化,解释方差为11.9%;因子4包括CH3COO-和C2O2-4,主要来源于高纬度的北温带北部森林大火,解释方差为11.6%.  相似文献   
10.
海洋沉积物中的多氯联苯   总被引:5,自引:0,他引:5  
综述了目前国内外对PCB的研究状况,并指出了PCB的来源、分布及其在沉积物和水相之间的循环受人为活动和生物活动等许多因素的影响。此外本文还概述了PCB的毒性研究近况以及测定其在沉积物中行为的方法,从而为控制环境污染提供了科学依据。  相似文献   
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