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陆源排污和海水养殖等经常造成近海富营养化。选用大型海藻或大型海藻与贝类组成的复合生态系统开展富营养化海区生态修复,在介绍富营养化海区特征及治理方法的基础上,分析不同修复生物及其组合对不同富营养化海区的适宜性。结果表明,贝类不宜单独作为修复生物;大型海藻可以有效吸收水中的溶解无机氮(DIN)、溶解无机磷(DIP),提高溶解氧(DO)浓度,是良好的富营养化海区修复生物。贝藻复合生态系统适宜在营养盐和颗粒物含量较高的海区开展生态修复。针对两种典型的富营养化海区(网箱养殖区、污水排放区),制定不同的生态修复技术和策略,介绍不同修复技术的修复生物品种选择、修复时间、养殖筏架、密度控制、操作方法与实施效果等,具有较好的应用前景,可为富营养化海区的生态修复研究与实践提供参考。 相似文献
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随着海水养殖的快速发展,养殖水体的自身污染和富营养化已成为严重的环境问题。作为生物滤器的大型海藻可以有效地吸收、利用养殖环境中多余的氮、磷等营养物质,从而减轻养殖废水对环境的影响,并提高养殖系统的经济输出,被广泛应用于鱼、虾和贝类等的综合养殖系统中,对富营养化海水养殖区进行生物修复。文章概述了大型海藻对富营养化海水养殖区进行生物修复的原因、原理、优点、研究进展以及应用大型海藻产生的效益和需要注意的问题。并指出在富营养化海水养殖区养殖大型海藻进行生物修复的方法可以实现海水养殖业的可持续发展。 相似文献
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南黄海水体富营养化日益加剧，作为我国绿潮孕育和暴发的主要场所，其水体富营养化的形成演变机制仍未完全清楚。为解析该区沉积物中营养元素磷（P）的释放特征和对水体富营养化的潜在贡献，采用改进的连续浸取法（SEDEX）分析了表层沉积中磷的含量水平和赋存形态，探讨了其生物有效性和对水体富营养化态势的影响。研究表明：总磷（TP）平均值为514 mg/kg，处于轻度污染，以无机磷（IP）为主要赋存形态（76.39%），有机磷（OP）次之，IP又以Ca-P为主（30.17%）。各形态磷平均贡献依次为OP>Ca-P>De-P>Fe-P>Ex-P。Ca-P和De-P属于生物不可利用磷，在沉积物中稳定性较强，在较粗粒径沉积物中含量较高。Ex-P和Fe-P易吸附于细颗粒沉积物表面，pH、温度、水体动力和氧化还原条件等是影响其吸附-释放的主要因素，南黄海海水酸化将促进Ex-P和Fe-P向海水释放，加剧海水富营养化程度。OP变化趋势显示，近岸以陆源输入为主，远岸生物过程具有重要贡献。南黄海生物有效磷（BAP:Ex-P+Fe-P+OP）平均值为240.1 mg/kg，占TP的46.4%，表明... 相似文献
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本研究在室内受控条件下,在虾、贝、藻的多池内循环养殖的基础上,采用残饵污染控制技术减少残饵生成量,并针对对虾养殖中产生的主要目标污染物质及其存在形态,镶嵌以相应的生物修复技术,探讨了综合生物修复技术对对虾养殖生态系统自身污染的修复效果。研究结果表明:采用虾、贝、藻及生物滤池综合生物修复技术可有效降低养殖水体中的悬浮物、溶解无机碳和溶解有机碳的含量。残饵即时修复技术可显著减少残饵生成量,但梭鱼和沙蚕对沉积物的扰动作用对综合生物修复效果产生了一定的负面影响。综合生物修复技术中大型藻类对水体中溶解无机氮的修复能力略显不足,在实际修复过程中需充分考虑大型藻类固氮速率和系统内生物排氮速率的平衡关系,并确保能满足大型藻快速生长最佳的水层空间。单靠微生物滤池对水体中有机物的修复能力并不理想,需辅助增加泡沫分离等技术,提高系统对大分子胶体的去除能力。本研究为进一步构建现场对虾养殖环境的综合生物修复技术体系奠定了基础。 相似文献
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任保卫 《海洋与海岸带开发》2014,(4):95-99
文章根据2012年8月对福建罗源湾海域的环境质量调查结果,结合海洋功能区划对海洋环境质量现状进行了评价与分析,并综合分析了海水中富营养化程度,沉积物中重金属的富集程度与生态风险效应。结果表明:该海域水质中除活性磷酸盐、无机氮和石油类存在超标外,其他环境因子均符合功能区划要求的海水水质标准。沉积物中除滴滴涕外,其他因子均符合海洋沉积物标准。20%的站位富营养化指数大于1,该海区的富营养化程度较低。沉积物中铅的富集程度相对较大,沉积物重金属的潜在生态危害轻微。 相似文献
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为定量评估多元环境因子对红树林分布的影响,探索区域红树林生境适宜性和修复潜力的空间分布格局,本研究应用最大熵模型评估厦门湾红树林生境适宜性,叠加土地利用/覆被数据分析红树林修复潜力。结果表明,在生物气候、地形、水质、沉积物、水文等5组环境变量中,影响厦门湾研究区内红树林分布的主要环境变量类型为温度、地形和水质。在单项环境因子中,离岸线距离、营养盐浓度、盐度等对厦门湾红树林生境适宜性的贡献度最大。适宜性和修复潜力较高的区域主要分布于九龙江河口、翔安下潭尾、海沧东屿等区域。与现存红树林的分布相对照,理论上还有约406.4 hm^2的高修复潜力区和1001.2 hm^2的中修复潜力区可考虑用于未来红树林修复。现有的保护区和修复工程已基本覆盖了上述大部分区域,未来厦门湾内的红树林修复选址可考虑泉州市安海湾沿岸、龙海市九龙江河口、漳州港沿岸和附近岛屿。本研究尝试采用新兴模型方法判断红树林的综合适生条件,并实现空间化、定量化的评估,其结果可为红树林修复选址提供重要的科学依据,并为区域红树林保护与修复管理提供决策支持。 相似文献
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江苏大丰地区潮滩由于水深较浅,潮流、波浪等动力较强,整个水层可视为边界层,其主体部分是对数层,即水流流速在垂向上呈对数分布。在潮流的加减速阶段,流速剖面将可能偏离对数分布,从而使对数剖面法计算出来的边界层参数造成误差。使用MIDAS-400用户化数据采集系统,在大丰潮滩获得了多层流速、浊度等同步高频观测数据,基于修正后的von Karman-Prandtl模型对u-lnz进行回归分析、数据内部一致性分析来定义流速对数剖面并与未修正前经典理论得到的边界层参数进行比较。分析结果表明,修正后的流速剖面更符合实际情况,边界层参数除了受水流加速度的影响外,还和沙纹等因素有关。另外,边界层参数的变化量与特征加速度负相关。 相似文献
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1Introduction The sediment dynamics of intertidal flats in-volves erosion, transport, and settling processes. A-mong these, the mechanisms of sediment transportare a key question. Progress has been made in awide range of associated areas, including sedime… 相似文献
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Many shorebirds on their non-breeding grounds feed on macrobenthic fauna which become available at low tide in coastal intertidal flats. The Eastern Curlew Numenius madagascariensis in Moreton Bay Australia, varies greatly in density among different tidal flats. This study asks: how important is the abundance of intertidal prey as a predictor of this variation? We quantified feeding curlews’ diet across 12 sites (different tidal flats, each re-visited at least eight times), through 970 focal observations. We also estimated the abundance of total macrobenthic fauna, potential prey taxa and crustacean prey on each tidal flat; measured as the number of individuals and a relative biomass index per unit substrate surface area obtained from substrate core samples. We estimated curlew density at each site using low-tide surveys from every site visit. 相似文献
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On aerial photographs, sandy tidal flats display (1) large sandy bedforms (> 10 m long, > 3 m wide), indicating effects of strong hydrodynamics on sediment relief, and (2) beds of seagrass and mussels, indicating stable sediment conditions. These physical and biogenic structures have been mapped from aerial photographs taken in a back-barrier tidal basin of the North Sea coast at low tide between 1936 and 2005. Fields of large intertidal sandy bedforms show a consistent spatial distribution in the central part of the basin, and have increased in area from 7.2 to 12.8 km2, corresponding now to 10% of the tidal flats. Areal expansion may be linked to a rise in average high tide level and an increase of the expansion rate from the 1960s to the mid 1990s might be traced back to an increased frequency of storm tides during this period. It is shown that expanding fields of large sandy bedforms have replaced mussel beds in the low tidal zone and displaced seagrass beds in the mid tidal zone. Fields of intertidal large sandy bedforms are expected to expand further with an accelerating rise in sea level, and it is recommended to monitor these physical indicators of sediment instability and disturbance of biogenic benthic structures by analysing aerial photographs. 相似文献
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A change in the elevation of bare tidal flats outside a mangrove area is an indispensable factor for the sustainable development of mangroves. Waterline extraction, as an effective and economical tool used in reconstructing the terrain of an intertidal zone, has been widely applied to open-coast tidal flats by constructing a digital elevation model (DEM). However, mangrove wetlands are usually located in wave-sheltered sites, such as estuaries and bays that have narrow tidal channels flanked by tidal flats. Changes in water level are affected by the dry-wet processes of complex landforms caused by tides. This article takes as a study case the area of Yingluo Bay, which covers the core region of the Zhanjiang and Shankou National Mangrove National Nature Reserve in southwestern China. Waterline extraction based on seventeen multisource and multispectral satellite images obtained from December 2014 to April 2015, combining the finite-volume coastal ocean model (FVCOM) hydrodynamic model in an iterative process, was used to generate a topographical map of the bare tidal flat outside the mangrove area in Yingluo Bay. The quality of the iterative DEMs was evaluated via six transects of a ground-based survey using Real - time kinematic (RKT) GPS in May 2015. The mean absolute error (MAE) and root mean square error (RMSE) of the DEM decreased with an increase in the number of iterations. In this study, the DEM in the third iteration was used as the final output because the difference from the previous iterative DEM satisfied an inversion-stopping criterion. The MAE and RMSE of the final DEM with the measured data were 0.072 and 0.09?m, respectively, without considering small tidal creeks. The method used in this study can be an effective and highly precise approach for detecting and reconstructing the historical terrain of a bare tidal flat outside a mangrove area. This work also has great importance regarding intertidal resource management and the sustainable development of mangroves facing the vulnerable coastal ecological environment. 相似文献
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Observations of boundary layer parameters and suspended sediment transport over the intertidal flats of northern Jiangsu, China 总被引：7，自引：0，他引：7
A current-turbidity monitoring system (CTMS) was deployed on the intertidal flat at Wanggang, northern Jiangsu during October 16-17, 2000, to measure the tidal current speeds and seawater turbidities at 5 levels above the seabed. Based upon the logarithmic-prof‘de equation, the boundary layer parameters, i.e., u*, Z0 and C60, were obtained for 247 tidal flow velocity prof‘des. Around 90% of the profiles were logarithmic according to the critical correlation coefficient. Internal consistency analysis shows that these parameters derived by different methods are consistent with each other. In addition, the height of the bedforms observed is close to the seabed roughness lengths calculated from the velocity prof‘des, indicating that the boundary layer parameters obtained can reveal the conditions at the sedimentwater interface on the intertidal flats. Suspended sediment concentrations were obtained from the 5 CTMS turbidity meters using laboratory and in-situ calibrations. The results show that the in-situ calibrated SSCs have a much higher accuracy than the laboratory calibrated ones. Calculation of suspended sediment fluxes on the intertidal flats, with a magnitude of 104 kg/m per spring tidal cycle, indicates that suspended sediment moves towards the northwest, which is reversal to the transport pattern controlled by the southward Northern Jiangsu Coastal Current in the sub-tidal zone and adjacent shallow waters. 相似文献
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Jongseong Ryu Jong Seong Khim Jin-Woo Choi Hyun Chool Shin Soonmo An Jinsoon Park Daeseok Kang Chang-Hee Lee Chul-Hwan Koh 《Journal of Sea Research》2011,65(4):390-400
Estuarine tidal flats are both ecologically and economically important, hence developing methods to reliably measure ecosystem health is essential. Because benthic fauna play a central role in the food web of tidal flats, in this study we set out to quantitatively describe the intertidal zonation of macro-invertebrates and their associations with specific environmental parameters along three transects in the Saemangeum tidal flat, Korea. The abundance and biomass of intertidal fauna with respect to five environmental parameters (i.e., shore level, mud content, coarse sand content, water content, and organic content) were measured, to identify environmental factors that influence macrofaunal distribution in intertidal soft bottom habitats. A total of 75 species were identified, with dominant species showing distinct zones of distribution along all transects. The number of species recorded in each transect was found to be dependent on sediment characteristics and salinity. Cluster analysis classified the entire study area into three faunal assemblages (i.e., location groups), which were delineated by characteristic species, including (A) ‘Periserrula–Macrophthalmus’, (B) ‘Umbonium–Meretrix’, and (C) ‘Prionospio–Potamocorbula’. Four environmental variables (i.e., shore level, water content, mud content, and organic content) appeared to determine factors that distinguished the three faunal assemblages, based on the discriminant analysis. The faunal assemblage types of the sampled locations were accurately predicted from environmental variables in two discriminant functions, with a prediction accuracy of 98%. It should be noted that the zonation of benthos in the lower section (C) of Sandong had been affected by the construction of a nearby dike, while this parameter had remained essentially unchanged at the other two location groups (A–B). Overall, the zonation of benthos from the Saemangeum tidal flat was explained adequately by the measured environmental variables, implying that faunal assemblages are closely associated with certain combinations of abiotic factors. The identification of such reliable associations may facilitate the development of statistical models to predict faunal distributions based on environmental variables at both local and regional scales. The entire study area was embanked in 2006 (one year after this study), and an integrated plan was set into force to develop claimed land into industrial, residential and agricultural districts, which also included a partial restoration program of the tidal flats located near to the study area. 相似文献
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以长江河口的沿岸及岛屿潮滩高潮滩湿地为研究区域,结合现场调查和实验室模拟分析,初步研究了大型穴居底栖动物无齿相手蟹(Sesarma denaan)活动对长江口潮滩沉积物-水界面无机氮交换以及界面处氮的生物地球化学循环的影响。结果表明,高潮滩蟹类底栖动物活动对潮滩滩面地貌施加了显著的改造作用,蟹类活动较集中的地段,蟹洞覆盖率达到2%~3%,滩面掘出沉积物高达1~1.5 kg/m2。潮水淹没情况下,小范围内高密度的蟹类活动能通过机体排泄、加强沉积物再悬浮及促进沉积物-水界面溶质交换等方式致使沉积物出现三态无机氮的巨大释放。蟹类活动造成的洞穴结构及对沉积物的翻动混合能增加沉积物中的氧气含量,促进沉积物中有机氮的矿化和NH4 的释放,造成无机氮在沉积物中的剖面分布特征发生较大变化。 相似文献
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H. A. C. Montgomery P. G. Soulsby I. C. Hart S. L. Wright 《Marine environmental research》1985,15(4):285-302
The eutrophication of Langstone Harbour, a large tidal basin, has been studied by statistically designed nutrient surveys. Rates of input of nutrients from the sea, from effluent discharges and from other sources, have been estimated. Sediment/water interactions have been shown to be important in the phosphate budget of the basin, but they are less important in the nitrogen budget. Deductions were made about the relative importance of the various inputs and processes affecting concentrations of nutrients in the water column.It is concluded that ecologically or aesthetically detrimental growths of macroalgae are unlikely to occur in Langstone Harbour in the foreseeable future and that the removal of nutrient inputs, formerly thought to be necessary, will not, in fact, be required.The principles of the experimental design and of interpreting the data are of general applicability to tidal waters where the ratio of natural to man-made inputs needs to be known, where eutrophication is, or is expected to become, a problem, or where the progressive accumulation of nutrients by recycling is suspected. 相似文献