共查询到20条相似文献，搜索用时 46 毫秒
1.
The striped dolphin, Stenella coeruleoalba, is an oceanic species that occasionally occurs in neritic habitats; in the Bay of Biscay it is abundant offshore and erratic in occurrence over the shelf. Given that prey assemblages differ widely among these habitats both in terms of taxonomic composition and of ecology, this would suggest that striped dolphins are able to shift from vertically migrating meso-pelagic prey to neritic or coastal prey types. We investigated the striped dolphin's dietary plasticity by examining the stomach contents of individuals stranded along the French Atlantic coast. 1109 prey items were identified belonging to 30 distinct taxa and their biomass was calculated. Fish accounted for 91% of the diet by number and 61% by mass; the rest was mostly cephalopods, crustaceans being present as trace. Specific composition included both oceanic (myctophid and sternoptychid fish; histioteuthid, gonatid and brachioteuthid cephalopods), neritic (gadids and anchovy; loliginid, sepiolid and sepiid cephalopods) and even coastal (atherinid fish) prey types, showing that these animals had changed their diet as they moved over the shelf. 相似文献
2.
Characteristic flora and fauna that are highly sensitive to disturbances colonize coastal detritic bottoms in the Mediterranean Sea. In the present study, a comparison of the assemblage composition and colonization by invasive macroalgae was made between two coastal detritic macrophyte assemblages, one dominated by rhodoliths (free-living non-geniculate Corallinales) and the other dominated by fleshy algae, in an area that has been exposed to important levels of anthropogenic disturbance, mainly pollution (including changed sedimentation regimes) in the recent past (bay of Marseilles, France). In comparison with less strongly impacted Mediterranean regions, the macrophyte assemblages in the bay of Marseilles were characteristic in terms of species identity and richness of coastal detritic macrophyte assemblages. However, extremely low species abundance (cover) was observed. As far as invasive species were concerned, Caulerpa racemosa var. cylindracea was only abundant in the rhodolith assemblage whereas the two invasive Rhodophyta Asparagopsis armata and Womersleyella setacea were mainly found in the fleshy algae assemblage. The seasonality observed in the Rhodolith assemblage seemed to be related to the development of C. racemosa var. cylindracea and did not follow the typical pattern of other Mediterranean assemblages. This study represents the first study of coastal detritic assemblages invaded by C. racemosa var. cylindracea. 相似文献
3.
《Marine Policy》2015
Meeting the United States׳ offshore renewable-energy goals for 2030 necessitates deploying approximately 9000 wind turbines along U.S. coastlines. Because siting bottom-mounted turbines in most nearshore coastal zones is either impractical or politically difficult, turbine developers are testing floating-platform turbine technologies for deeper waters. Deepwater, floating-platform turbines have the advantages of being sited in the highest quality winds farther offshore, movable if desired, and located beyond the horizon, out of sight from shore. This paper reports on conversations with 103 coastal stakeholders at community meetings regarding development and testing of floating turbines off the coast of Maine, U.S.A. Using naturalistic field methods, this essay reports common questions and concerns of commercial lobstermen, fishermen, and coastal civic leaders. Early-stage conversations suggest that once coastal community members understand the benefits and impacts of wind farm development on their quality of life, many share specific preferences for where offshore developments could be located. Citizens׳ remarks are sophisticated, nuanced, and innovative and include robust ideas for pairing turbine siting with fishery conservation. Findings imply that when looking to site offshore turbines in public, multiple-use ocean spaces, developers, planners, and coastal communities should engage early and often in two-way conversation rather than one-way outreach. 相似文献
4.
Connell SD 《Marine environmental research》2001,52(2):115-125
There remains little understanding of the relationship between the ecologies of urban habitats (pilings and pontoons) and natural habitats (rocky reef) for sessile plants and animals (epibiota) living on urbanised coasts. This study describes the structure of subtidal assemblages of epibiota among pilings, pontoons and adjacent rocky reef in Sydney Harbour, Australia. I tested the prediction that the experimental provision of substrata of the same age and composition in all three habitats would produce assemblages that: (1) differed among all three habitats; and (2) differed most on floating pontoons relative to the two fixed habitats (pilings and reef). As predicted, the results suggested that both pilings and pontoons, particularly the latter, create novel habitats for epibiotic assemblages independent of age and composition of substratum. It is not fully understood why these urban structures act as such different habitats from natural rocky reefs. The important point is that they are different and we are yet to understand the implications of this for the ecology of coastal areas subject to urbanisation. 相似文献
5.
《Ocean & Coastal Management》2007,50(8):597-605
Given the increasing competition for marine resources, regulatory strategies that benefit multiple stakeholders are increasingly important. Offshore wind power generating facilities are becoming more common in the marine environment and alter the characteristics of the fisheries in the surrounding area. Floating wind turbines can act as fish aggregating devices (FAD), thereby increasing the catchability for some species. Many marine recreational fisheries are open access without effort restrictions; therefore, control of total harvest is difficult. Creating a limited entry recreational fishery and excluding commercial fishing from the area surrounding offshore wind turbines may aid in controlling total harvest and may benefit several important stakeholder groups: (1) recreational and commercial fishermen in terms of higher recreational catch rates and potentially higher overall yield, (2) fisheries managers in terms of more precise control of recreational fisheries harvest, and (3) owners of offshore wind power facilities in terms of reduced risk of damage to infrastructure due to fishing activity. We discuss the compatibility of wind power facilities and fisheries, conditions conducive to this compatibility, and provide an example from a proposed offshore wind power facility in the Adriatic Sea and its potential to affect the fisheries management there, particularly for bluefin tuna (Thunnus thynnus). 相似文献
6.
《Estuarine, Coastal and Shelf Science》2005,62(1-2):271-282
Despite the long history of urbanisation of the coastal environment, there remains very little understanding of the impact of such construction on the ecology of intertidal habitats. Rock rubble groynes are becoming the favoured approach to reduce beach erosion in Dorset, England. This study investigated the assemblages of 10 rock rubble groynes over a 2-year period, taking four factors into account: age of the groyne (<1 year, 2 years, 6 years and 7 years old), tidal height (high shore versus low shore), groyne aspect (east versus west side) and microhabitat (open rock versus rockpool). The age of the groyne, tidal height and microhabitat were significant factors in the composition of the assemblage. The groyne aspect, however, did not significantly influence community composition. These findings are discussed and related to succession and community development theory. 相似文献
7.
对于海上浮式风机而言,由于受到剪切风、塔影效应、浮式基础运动等因素的共同影响,其气动载荷会更加复杂,因此如何准确快速地对海上风力机的气动性能进行预估显得尤为重要。基于速度势的非定常面元法理论,研究海上浮式风机气动载荷特性,编制了相关的计算程序。以NREL 5 MW风机为例,建立了叶片和尾流的三维数值模型,计算得到了不同风速下风机的输出功率以及叶片表面的压力分布,对比数据结果分析了该方法的可靠性。针对非定常流动,模拟了剪切风和塔影效应的作用,并重点分析了浮式基础运动对风机气动载荷的影响。研究表明,浮式基础的纵荡和纵摇会增加输出功率的波动幅值,艏摇运动会导致单个叶片上的气动载荷产生较大的波动,为浮式风机叶片控制提供了参考。 相似文献
8.
为加强对海上风电项目的用海管理,规范海上风电产业的用海活动,促进海域空间资源的科学合理开发利用,文章采用海上风电用海权属、风机遥感影像解译和海上风电用海项目核查的数据,以2016年年底为时间节点,对江苏省海上风电用海项目的确权管理、疑似疑点疑区、项目承担企业和项目运营情况进行调查,并根据调查结果提出存在的问题和建议。研究结果表明:江苏省共确权海上风电用海项目44个,已建设40个,总建设面积为6 712.91hm~2;疑似疑点疑区海上风电用海项目有26个;项目承担企业主要包括华能国际电力股份有限公司等;已建成投产并网的海上风电用海项目有29个,总投资额近293亿元,年发电量约50kW·h,年产出额近34亿元;目前海上风电用海项目主要存在未取得海域证、部分风机偏离原批复界址范围和规划布局不合理的问题,未来应坚持保护优先和适度开发原则、规范项目管理、优化规划布局以及加强动态监测。 相似文献
9.
基于CCMP(cross-calibrated multi-platform)再分析风场数据,研究了0903号台风经过前后21天对我国东部5个海上风电场的影响。发现:风机的输出功率受其所处台风场的相对位置影响,台风北进过程中前沿(后沿)在2009年6月18—19(27—28)日使得风机输出功率显著增加,而6月22—23日,台风中心进入东海时, 5个站位风机输出功率最低。唐山市海港区S1站单机运营能力最低(64.3%)且额定容量最低(0);嘉兴市平湖县S4站单机运营能力最高(88.1%);南通市如东县S3站单机额定容量最大(13.1%)。0903号台风过境整个过程中,风速未超过风机的切出风速,对我国东部海洋风力发电场,提高了发电量。 相似文献
10.
The present study aims to evaluate if invasion of Caulerpa racemosa var. cylindracea can affect both alpha and beta diversity in Mediterranean coastal system. The following hypotheses were tested: (i) measures of alpha diversity differ between invaded and non-invaded assemblages (ii) this pattern is consistent between different habitats, (iii) assemblages from habitats which are naturally very different tend to be more similar when invaded compared to non-invaded situations. Results showed that Mediterranean benthic assemblages invaded by C. racemosa var. cylindracea were characterized by lower values of alpha diversity than non-invaded assemblages; moreover, differences between deep (25 m) and shallow water (5m) assemblages appeared lower in invaded than in non-invaded areas, with a decrease of beta diversity. This homogenisation of habitats was related to a lack of several characteristic species and to a higher abundance of few opportunistic species in invaded areas, particularly turf-forming algae. Moreover, variability in taxa composition was lower in invaded than in non-invaded assemblages in both habitats. 相似文献
11.
Gabriele La Mesa Andrea Molinari Silvia Gambaccini Leonardo Tunesi 《Marine Ecology》2011,32(1):104-114
Variability of fish assemblages across habitat structures can depend on spatial scales. A hierarchical sampling design was used to assess the spatial variability of temperate fish assemblages in different habitats and at multiple scales. Underwater visual censuses were carried out along the coasts of Elba Island (NW Mediterranean) on Posidonia oceanica beds, rocky algal reefs and sandy habitat at three spatial scales, namely tens of metres (individual replicates), hundreds of metres (sites) and tens of kilometres (locations). At the assemblage level, there was a clear relationship between fish and habitat type and the observed habitat‐related differences were largely dependent on species identity. Fish assemblages on P. oceanica beds and rocky reefs shared a high number of species, whereas overlap with sandy assemblages was negligible. Multivariate analyses revealed significant differences in fish assemblages among habitats, although there was also a significant habitat × site interaction. These differences relied mainly upon assemblage composition and species richness. Assemblages on rocky reefs and P. oceanica meadows usually harboured a higher number of species and individuals compared with sandy assemblages. Nevertheless, the patterns of habitat‐related differences in species richness and, especially, in the total number of fish, changed significantly from site to site. Eight species showed significant differences over habitats, but they were not consistent due to the interaction of habitat with site. Predictability of fish at both assemblage and population levels decreased with the scale of observation, and the spatial pattern of fish observed at the smallest scale was likely dependent on factors other than habitat type. 相似文献
12.
针对海上风电整机系统,建立了一体化流固耦合分析方法。在模拟过程中,采用浸入边界法解决风机叶片旋转引起的静动干涉问题,利用改进的守恒式 level set（简称 ICLS）方法捕捉海浪自由面,并使用交错迭代法求解流固耦合方程。通过构建 “风机—塔架—基础”一体化流固耦合数值模拟方法,能够在一次仿真计算中实现海上风电整机系统的全过程数值模拟,准确求解多荷载耦合作用下“风机—塔架—基础”的整体结构动力响应。以某单桩式海上风电工程为例,验证了本方法能够实现对海上风电整体系统的一体化分析。 相似文献
13.
Offshore wind power has a large potential as a vast resource for delivering clean and abundant energy on a global scale. However, the siting of offshore wind farms in the coastal zone has negative effects on the seascape. This might be particularly evident in the case if offshore wind farms are located close to areas with recreational activities in the coastal zone. Extending the analysis from a previous investigation of the preference for reducing visual impacts from offshore wind farms, the present paper utilises the same sample representing the Danish population. Based on the stated preferences from a Choice Experiment in a mail survey the preferences for reducing visual disamenities from offshore wind farms among different types of coastal zone users are compared to the preferences of less frequent users of the coastal zone. The results strongly indicate that in addition people who can see offshore wind farms from their residence, anglers and recreational boaters, i.e. users of the coastal zone, significantly perceive the visual impacts to be more negative compared to people who do not use the coastal area for those specific purposes. Furthermore, the results also indicate that respondents who visit the beach on a frequent basis also have stronger preferences for reducing the visual disamenities, when compared to less frequent visitors. As a consequence, the specific users and frequent visitors of the coastal zone are willing to pay approximately twice as much to have future offshore wind farms moved further away from the coast, when compared to less frequent users and visitors. These results display that, given the wind farms are not located at relative large distance from the shore, the recreational value of the coastal use is potentially jeopardised by visual impacts from offshore wind farms. From an energy planner's point of view, these results are noteworthy, as they – everything else being equal – point towards that potential gains in capital cost (investment, construction and running costs) by locating offshore wind farms at relative close distances from the shore might be outweighed by the visual disamenity costs in coastal areas with a large recreational activity. As such, the optimal location, i.e. distance from the shore, of offshore wind farms might be closer to the coast in areas with little recreational activities compared to coastal areas with a higher level of recreational activities. 相似文献
14.
D.A. Smale G.A. Kendrick K.I. Waddington K.P. Van Niel J.J. Meeuwig E.S. Harvey 《Estuarine, Coastal and Shelf Science》2010
At regional scales, the distribution of species and the structure of assemblages vary with latitude within many marine and terrestrial systems. The oligotrophic coastal waters of Western Australia (WA) support highly speciose and endemic assemblages, yet spatial patterns in benthic structure are currently poorly known. We examined benthic assemblage composition along a latitudinal gradient of 28.5–33.5°S and a depth gradient of 14–62 m, on subtidal reefs in warm-temperate WA. We surveyed benthos using a remotely triggered digital stills camera. In total, we sampled macroalgae and sessile invertebrates at 201 sites spread across four locations. Percent cover of coarse taxonomic groups and dominant species was estimated from over 2000 photoquadrat samples. We recorded significant differences in benthic assemblage composition between locations, and along depth gradients within each location. However, the magnitude of change with depth was not consistent between locations, and shifts in assemblage composition along the depth gradients were not as pronounced as expected. The percent cover of all dominant benthic groupings differed between locations, and several key taxa, such as the kelp Scytothalia dorycarpa, brown foliose macroalgae, hard corals and sponges, changed predictably along the latitudinal gradient. Our study adopted a coarse taxonomic, but assemblage-wide, approach to describing macrobenthic assemblages, and clear differences between locations and depths were detected. The surveys have provided baseline data on broad scale ecosystem structure against which to detect future ecological change. 相似文献
15.
Macroalgae build biogenic habitats which give shelter and provide a suitable physical environment for a great variety of organisms. Structural complexity of algal substrates may influence the composition of their attached epifauna. The aim of this study is to test whether the taxonomic relatedness of the algal hosts and the functional groups to which they belong influence the species richness and composition of their epifaunal bryozoans. We analysed 36 algal genera from the Atlantic coast of South America between 42°S and Cape Horn. Changes in bryozoan species richness (number of species) among different algal functional groups (filamentous algae, foliose algae, corticated foliose algae, corticated macrophytes) were non-significant. The composition of the epifaunal assemblages differed significantly only between filamentous and foliose algae. Sheet-like bryozoans (i.e. encrusting, pluriserial colonies) were more frequent on foliose than on filamentous algae, while runner-like species (i.e. uniserial stolons) were characteristic epibionts on filamentous thallii. Similarity of bryozoan assemblages increased with increasing taxonomic relatedness of their hosts. As most filamentous seaweeds analysed in this study are members of the Order Ceramiales, the influence of algal taxonomic relatedness and functional groups on the composition of their bryozoan assemblages can be viewed as two different aspects of the same phenomenon. 相似文献
16.
风机基础作为海上风机整体结构的重要组成部分,承受着上部风机所受到的风浪流荷载,并且对风机的安全性及可靠性至关重要。吸力式桶形基础由于其安装简单和可重复利用等优点,在海洋平台基础中得到了广泛应用,并逐步应用于海上风机基础中。但由于海上风机与海洋平台在海洋环境中的荷载工况有一定的差别,仍需要通过对其承载特性研究现状进行全面认识,以实现吸力式桶形基础在海上风机基础中的可靠应用。文中通过总结和评价现有研究对桶形基础在不同土体条件以及荷载条件下进行试验及数值模拟分析得到的研究结果,综述了静荷载和循环荷载作用下砂土和黏土中的吸力式桶形基础的承载特性研究现状,以及海上风机吸力式桶形基础的相关研究。文章展望了目前应用于海上风机基础的桶形基础仍缺乏的研究,为海上风机吸力式桶形基础的可靠应用及后续研究提供重要参考。 相似文献
17.
18.
为掌握我国海上风电发展规模和趋势，进而为海上风电发展决策提供参考，文章基于灰色系统理论的3种模型，对全国和主要沿海地区海上风电发展规模和趋势作出预测。研究结果表明:装机量可作为海上风电发展规模的预测指标；通过历史数据模拟，GM（1，1）比NDGM和DGM（2，1）的拟合效果更好且预测精度较高，适用于海上风电装机量预测；GM（1，1）对海上风电发展的短期（1～3年）预测准确率较高，而中长期（5～10年）预测准确率有待检验；海上风电主要地区的装机量将持续增长，但各地区呈现不同的增长率；江苏海上风电发展在多年快速增长后可能放缓，广东和福建有望“接棒”江苏而成为海上风电大省；国内海上风电产业仍处于成长阶段，经济稳妥的发展策略是必然选择。 相似文献
19.
Blockley DJ 《Marine environmental research》2007,63(4):409-427
Worldwide, urbanisation has resulted in extensive replacement of natural habitats with man-made habitats. In Sydney Harbour, Australia, approximately half of the natural foreshore has been replaced by seawalls. Many of these have wharves built over part of their length, which could affect intertidal assemblages on seawalls beneath the wharves. This was tested by sampling and comparing assemblages under and not under wharves in Sydney Harbour. Assemblages differed between the two habitats, with greater cover of macro-algae and abundance of grazing molluscs on seawalls without a wharf and, to a lesser extent, greater cover of sessile invertebrates on seawalls under a wharf. There was, however, considerable spatial variability among locations in composition of assemblages and the species dominating differences between the two habitats. The impact of multiple artificial structures in close proximity and the variability among apparently homogeneous artificial habitats must be considered for the management of urbanised estuaries. 相似文献