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811.
In this paper, the role of nutrient transports between marine basins is investigated for cost-effective solutions to predetermined marine basin targets. The interdependent advective nutrient transports as well as retentions among the seven major marine basins of the Baltic Sea are described by input-output analysis. This is in contrast to prior economic studies of transboundary water pollution that include only direct transport between the basins. The analytical results show that the difference in impacts between transport specifications depends mainly on the openness of the basins, that is, their transports with other basins. The application on Baltic Sea shows significant differences in costs and policy design between the nutrient transport specifications. The reason is that the Sea is characterized by long water and nutrient residence times, so relatively large part of nutrients are transported among basins. 相似文献
812.
Nine similarity indices based on phytoplankton community structure were examined for their sensitivity to assess different
levels of eutrophication. Two phytoplankton data sets, one from an open coastal system and one from a semi-enclosed gulf,
associated with different nutrient dynamics and circulation patterns were used for evaluating the indices. The results have
shown that similarity indices, measuring interspecific association and resemblance of phytoplankton communities between enriched
areas and control sites, were effective for detecting spatial and temporal dissimilarities in coastal marine ecosystems. The
structure of the oligotrophic habitat as a potential source of ambiguity for the results was discussed, whereas the validity
ranges and the potential applicability of this method were deemed to be dependent on the size of the fraction of the common
species among the samples, and the similarity of the classification patterns resulted from this subcategory and those extracted
from the overall community data. Furthermore, the study provides a new technique based on the use of the “Box and Whisker
Plot” designed to distinguish opportunistic and rare phytoplanktonic species. The similarity indices, applied solely to the
dominant species abundance, were more sensitive to resolve eutrophic, mesotrophic and oligotrophic conditions. This procedure
can be proposed as an effective methodology for water characterization and can also be used as a qualitative tracer for detecting
renewal processes of coastal marine ecosystems. 相似文献
813.
This article attempts to put the light on the air quality of the Black Sea region of Turkey. In addition to that, it endeavors to locate the possible sources of the different pollutants at local, regional and long range transported scales. About 196 rainwater samples were collected over the Black Sea region of Amasra between 1995 and 1999, and analyzed for major ions and trace elements using spectrophotometric techniques. Andersen wet only rain samples were used to collect rain events, where the rain sample was filtered inline using 0.45 m cellulose acetate filters. Major anions (SO4
2-, NO3
- and Cl-) were determined using ion chromatography, whereas metals (Ca, Mg, Al, Fe, Na, K), werequantified using ICP-AES. This study shows that, the Black Sea region receives different amounts and types of anthropogenic pollutants via long-range transport according to trajectory models. Although the pH of rain water is not considered acidic (pH = 5.21) yet the neutralizing species are lower than other sites around Europe. 相似文献
814.
The background of this work is the international decision process with regard to the selection of chemicals to be assessed with priority. In order to stress the precautionary principle, mass flows were analysed rather than concentrations, threshold values, etc., as preferred by the chemical legislation (which still excludes the marine area). Lindane, hexachlorobenzene (HCB), trichloroacetic acid and its sodium salt, medium-chained chlorinated paraffins and tributyltin (TBT) were selected due to their great relevance for the marine area. Trichloroacetic acid is an interesting model compound on account of its accidental formation by degradation of volatile chlorinated hydrocarbons and during chlorination processes. In addition, a hypothetical compound was modelled, representing a highly water-soluble substance with low vapour pressure. The balancing area is the Baltic Sea and its catchment area. In order to model the substance flows, the 'Input/Output-load model' has been developed. The model quantifies the shift and the distribution of a yearly load of the substance investigated from the terrestrial-limnic into the marine compartment (Baltic Sea). Water-soluble substances, which are usually considered to be of no concern, may enter the sea in great amounts and, if not degradable, remain there. It turned out to be necessary to take into account remobilisation, unintended formation and point as well as line-sources. 相似文献
815.
大气沉降可为上层海洋带来生物可利用性的营养元素(如N、P、Fe等),从而改变浮游植物的初级生产过程及群落结构,并影响海洋的碳循环.于2014年春季在南黄海开展2次船基围隔培养实验,通过人工添加沙尘、灰霾颗粒及多种营养盐来模拟大气沉降对海洋表层浮游植物生长的影响,结果表明:南黄海北部B07站浮游植物生长主要受到磷限制;南黄海中部H10站则主要受氮限制.沙尘添加在B07站和H10站均显著促进小型和微型浮游植物生长,对微微型浮游植物生长的促进作用不明显.灰霾添加在B07站对浮游植物生长总体呈现抑制作用,且主要抑制小型和微型浮游植物生长,对微微型浮游植物则为先抑制后促进;在H10站对浮游植物的影响整体呈现先抑制后促进,培养前期对各粒级浮游植物均有抑制作用,培养后期对微型和微微型浮游植物有促进作用. 相似文献
816.
南海渔业资源具有"公共池塘资源"的基本属性是导致其面临地缘政治紧张局势的内生困境,为此有必要从南海渔业在低敏度领域的现实表征为立足点,与南海领土主权与海域划界争端等高敏度领域相互结合的角度考察与评判南海渔业资源环境保护的主权变动动向:应该注重传统捕鱼权在南海周边国家的海洋管辖权边界的应用.以东南亚渔业管理组织和新建立南海渔业管理组织联合协同组织新的东南亚渔业管理组织必定有助于南海渔业资源纠纷的解决. 相似文献
817.
海河及渤海表层沉积物中多环芳烃的分布与来源 总被引:11,自引:0,他引:11
采集海河和渤海表层沉积物样品,测定16种EPA规定多环芳烃.海河∑PAH含量(干重)范围为445~2185 ng·g-1,平均值为964 ng·g-1;渤海∑PAH含量范围为171~290 ng·g-1,平均值为226 ng·g-1.海河塘沽区段和天津市区段沉积物中∑PAH含量比郊区段含量高.LMW/HMW(低分子质量/高分子质量)和异构体比值分析表明,生物质及煤的燃烧为海河表层沉积物中PAHs主要来源;对于渤海湾大部分区域来说,石油污染是其PAHs的主要来源,而热解来源的PAHs主要以生物质及煤的燃烧为主;滨海旅游度假村附近海域因受旅游活动影响而燃烧源的贡献较大.风险评价表明,海河及部分渤海海域存在潜在生态危害,滨海村附近海域存在潜在生态风险可能性较低. 相似文献
818.
819.
Andrea Bigano Francesco Bosello Roberto Roson Richard S. J. Tol 《Mitigation and Adaptation Strategies for Global Change》2008,13(8):765-791
While climate change impacts on human life have well defined and different origins, the interactions among the diverse impacts
are not yet fully understood. Their final effects, however, especially those involving social-economic responses, are likely
to play an important role. This paper is one of the first attempts to disentangle and highlight the role of these interactions.
It focuses on the economic assessment of two specific climate change impacts: sea-level rise and changes in tourism flows.
By using a Computable General Equilibrium (CGE) model the two impacts categories are first analysed separately and then jointly.
Considered separately, in 2050, the forecasted 25 cm. of sea level rise imply a GDP loss ranging from (−) 0.1% in South East
Asia to almost no loss in Canada, while redistribution of tourism flows – which in terms of arrivals favours Western Europe,
Japan, Korea and Canada and penalises all the other world regions – triggers GDP losses ranging from (−) 0.5% in Small Island
States to (−) 0.0004% in Canada. GDP gainers are Australia, New Zealand, Western Europe, Middle East and South Asia. The impact
of sea level rise and tourism were simulated jointly and the results compared with those of the two disjoint simulations.
From a qualitative point of view, the joint effects are similar to the outcomes of the disjoint exercises; from a quantitative
perspective, however, impact interaction does play a significant role. In six cases out of 16 there is a detectable (higher
than 2% and peaking to 70%) difference between the sum of the outcomes in the disjoint simulation and the outcomes of the
joint simulations. Moreover, the relative contribution of each single impact category has been disentangled from the final
result. In the case under scrutiny, demand shocks induced by changes in tourism flows outweigh the supply-side shock induced
by the loss of coastal land.
相似文献
Francesco BoselloEmail: |
820.