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41.
Oligotrophic areas harbour low macrofaunal abundance and patchy distribution. In these areas it is necessary to test the reliability of biological indicators, especially those based on taxonomic sufficiency where the level of identification is balanced against the need for ecological information and could affect the efficiency of bioindicators. The BOPA (benthic opportunistic polychaetes and amphipods) index was applied in five coastal areas subjected to different perturbations (aquaculture, harbour, brine, sewage, and thermal pollution) in the Canary archipelago, an oligotrophic area of the Atlantic Ocean. Significant differences in the BOPA index between impact and control sites were only found in the area affected by a harbour. Perturbations such as aquaculture, brine or sewage discharge produce only a weak response of the BOPA index, whereas no effects were observed at thermal pollution‐impacted locations. The BOPA index should be used with caution to establish the ecological status of coastal water bodies in the Canary Islands, since it was only reliable in strongly impacted regions (enlargement harbour works), but did not respond clearly to other man‐induced perturbations.  相似文献   
42.
环渤海地区港口与城市关系的动态测度及驱动模式研究   总被引:2,自引:0,他引:2  
港城交互作用是港口城市形成、演化并实现可持续发展的关键因素,因此,如何测定港城关系并从中揭示港城交互作用的模式是港口城市研究的一个难点问题.一直以来,港城关系中港口功能与城市功能定量分析方法以及港城互动关联机制的研究比较薄弱.在RCI基础上,提出DCI的概念、内涵及其算法,并以此为基础,对环渤海地区主要海港城市的港城关系状况及DCI值动态变化趋势进行定量测度,并运用脉冲响应函数对港城驱动模式进行系统分析,揭示不同港口城市在港城相互作用方面的具体差别与联系,丰富地理学对于港城关系内在机理的认识.结果显示:环渤海地区12个海港城市港城关系状况可以分为港口驱动型、城市驱动型和港城稳定型三类;变动趋势可以分为持续上升型、持续下降型及波动型三类;港城交互作用机制及稳定性存在明显差别.港城关系的强弱或倾向性与港口或城市规模没有直接关系,而是与港口或城市发展阶段、港口与腹地的关系等深层次问题密切相关.  相似文献   
43.
《Geodinamica Acta》2013,26(5-6):209-223
The 2.4 ka shoreline evolution on the Island of Vis has been investigated. It represents a particularly interesting area for this kind of investigation due to the existence of the submerged archaeological remains, the antique port of Issa, as well as to the existence of geomorphological and biological sea-level markers. The actual depths of the different parts of the submerged quay have been mapped and measured with respect to the present mean sea-level, applying corrections for tide and atmospheric pressure values at the time of the surveys. The functional heights related to the sea level at the time of construction have also been taken into account. These data were further compared with predictions derived from a glacio-hydro-isostatic model associated with the Last Glacial cycle. During the investigation of the coast, tidal notches and algal rims were found. They were mapped, measured and correlated with results of the submerged port remains, as well as with other available data along the Croatian coast.

Our results demonstrate a 199±25 cm sea-level change during 2.4 ka on the Island of Vis. Taking into account the total relative sea-level change, an average rate of around ~0.83 mm/yr is derived. If the isostatic-eustatic component is separated, a tectonic subsidence rate ranges between 0.17 and 0.3 mm/yr depending on the predicted model used. Compared to the Northern Adriatic area, the Island of Vis shows a much smaller component of tectonic subsidence.  相似文献   
44.
Patterns and levels of chlorinated aromatic contaminants (DDTs, PCBs, non-ortho PCBs and PCDD/Fs) in blubber tissue were compared among six sample groups of male harbour porpoises (Phocoena phocoena) from the Baltic Sea, the Kattegat-Skagerrak Seas and the west coast of Norway. A principal component and classification analysis showed that mature harbour porpoises from the Baltic had significantly different contaminant patterns than animals from the Kattegat-Skagerrak and Norway. ANOVAs showed that mature porpoises from the Baltic had higher levels of ΣPCB and several individual PCBs and PCDD/Fs than the Kattegat-Skagerrak and the Norwegian samples and higher ΣDDT than the Norwegian. A comparison between immature porpoises showed that Baltic animals had higher levels of ΣPCDD/F than the corresponding sample from the Kattegat-Skagerrak. The levels of ΣDDT, ΣPCB and Σnon-ortho PCB were significantly higher in animals collected during 1978–81 compared to animals collected in 1988–90 indicating a temporal decline of these organochlorines in the Kattegat-Skagerrak Seas. The contaminant levels recorded in the Baltic Sea are a serious cause for concern and could have management implications for the already threatened harbour porpoises in this area.  相似文献   
45.
射阳湖历史变迁研究   总被引:8,自引:1,他引:7  
凌申 《湖泊科学》1993,5(3):225-233
射阳湖是苏北历史上著名的大湖。早全新世因受海侵影响,本区是里下河浅水海湾的一部分;中全新世时,由于西冈等岸外砂堤的形成,本区成为古泻湖,后因海岸东迁,淡水冲灌,古泻湖逐渐演变为淡水湖。1128年黄河夺淮后,大量泥沙进入湖区,湖区淤积迅速,成为沼泽型湖泊,加之人类活动因素的显著影响,射阳湖逐渐演变为里下河平原的一部分。  相似文献   
46.
采用延绳式、浮筏式、立桩式在外海深水区进行马氏珠母贝[Pinctada m artensii (Dunker)]人工养殖试验,结果表明:经 11 个月的养殖,其成活率分别为延绳式 56.3% ,浮筏式 32.8% ,立桩式20.8% ,而同期在港湾浅水区养殖时,其成活率分别为浮筏式 28.8% ,立桩式 18.5% 。而且外海深水区养殖马氏珠母贝生长快,个体大,体质强,病害少,附着物少。此外,外海深水区延绳式养殖设施抗风浪能力强,是开发利用外海深水区的一种良好方式  相似文献   
47.
Chau KW 《Marine pollution bulletin》2005,51(8-12):1078-1084
The eutrophication phenomenon often leads to undesirable water quality. This paper delineates an unsteady three-dimensional finite difference numerical model for eutrophication dynamics in the coastal waters of Tolo harbour, Hong Kong, employing the numerically generated, boundary-fitted, orthogonal curvilinear grid system as well as a grid “block” technique. It models the transport and interaction of nine water quality constituents. Adjustments of values of some kinetic coefficients in the model are effected through calibration with field data. It is demonstrated that the model can reasonably reproduce the interactions amongst all the water quality constituents, the eutrophication processes and, in particular, the featured bottom water anoxic condition during the summer in Tolo harbour.  相似文献   
48.
杜渺  董庆松 《海岸工程》1996,15(2):19-24
分析苏北里下河地区排水入海的最大干河--射阳河在本流域中的地位和作用,目前河道淤积,工程老化和水污染严重等现状,以及射阳河蕴藏着的河海联运,水源充足,自然和人文景观众多潜在优势;阐述了整治和综合开发利用射阳河的重要性和迫切性;提出了整治和开发利用的3条总体原则,大体思路及保证顺利实施的关键措施。  相似文献   
49.
AnalysisofthedevelopmentandcausesofformationofEucampiazoodiacusredtideinXiamenHarbor¥ZhangShuijin(ReceivedJune20,1994;accepte...  相似文献   
50.
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