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1.
Modeling of spring bloom in the western subarctic Pacific (off Japan) with observed vertical density structure 总被引：1，自引：0，他引：1
A. Yoshimori J. Ishizaka T. Kono H. Kasai H. Saito M. J. Kishi S. Taguchi 《Journal of Oceanography》1995,51(4):471-488
Effects of vertical stability on spring blooms of phytoplankton were investigated for the western subarctic Pacific ocean using a one-dimensional (depth) ecosystem model. In the model, vertical stability was expressed by diffusion constants calculated from observed density distribution. Dynamics of phytoplankton in blooms was calculated by the model using the vertical diffusion. Then, the calculated results were compared with the Coastal Zone Color Scanner (CZCS) data. The comparison shows that the shallow surface mixed layer causes early start days of spring blooms at inshore (northern) stations. In addition, spring blooms continue long at inshore (northern) stations since a water column has weak stability. This is because weak stability of a water column causes large nutrient supply from a deep layer and large diffusive transport of phytoplankton biomass from the subsurface maximum. 相似文献
2.
V. I. Vedernikov V. G. Bondur M. E. Vinogradov M. R. Landry M. N. Tsidilina 《Oceanology》2007,47(2):221-237
The anthropogenic impact on the biomass of coastal plankton communities caused by submerged disposal of urban sewage waters (dumping) was studied. The observations were carried out in August–September of 2002–2004 in Mamala Bay (Oahu Island, Hawaii) using satellite and sea truth methods. An analysis of the variability of the integral indicators of the water column determined on the basis of shipborne measurements allowed us to divide them into two groups: the elements most sensitive to the pollution (heterotrophic bacteria (H-Bact), the phototrophic cyanobacteria Synechococcus spp. (SYN), and chlorophyll a (CHLa)) and the elements that manifested episodic positive dependence on the inflow of the polluted waters (heterotrophic unicellular eukaryotes, small unicellular algae, the phototrophic green bacteria Prochlorococcus spp., as well as the total biomass of microplankton). It was shown that the submerged wastewater disposal in the region of the diffuser of the dumping device led to an insignificant (1.2–1.4 times, on the average) local increase in the integral biomass of H-Bact, SYN, and in the content of CHLa. A similar but sharper (1.5–2.1, on the average) increase in these parameters was found in the water layers with maximal biomasses. The possible pathways of disposed waters (under the pycnocline, at its upper boundary, and in the entire mixed layer) were analyzed on the basis of studying the vertical displacement of the biomasses of H-Bact, SYN, and prochlorophytes. The possibility of using the optical anomalies distinguished from satellite data as markers of anthropogenic eutrophication caused by dumping was confirmed. Application of such markers depends on the water transparency and on the shapes of the curves of the vertical distribution of autotrophic organisms. 相似文献
3.
Ship-of-opportunity based phycocyanin fluorescence monitoring of the filamentous cyanobacteria bloom dynamics in the Baltic Sea 总被引：1，自引：1，他引：1
J. Seppl P. Ylstalo S. Kaitala S. Hllfors M. Raateoja P. Maunula 《Estuarine, Coastal and Shelf Science》2007,73(3-4):489-500
Distribution of cyanobacteria cannot be evaluated using chlorophyll a (Chla) in vivo fluorescence, as most of their Chla is located in non-fluorescing photosystem I. Phycobilin fluorescence, in turn, is noted as a useful tool in the detection of cyanobacterial blooms. We applied phycocyanin (PC) fluorometer in the monitoring of the filamentous cyanobacterial bloom in the Baltic Sea. For the bloom forming filamentous cyanobacteria Aphanizomenon flos-aquae and Nodularia spumigena, PC fluorescence maximum was identified using the excitation–emission fluorescence matrix. Consequently, the optical setup of our instrument was noted to be appropriate for the detection of PC, and with minor or no interference from Chla and phycoerythrin fluorescence, respectively.During summer 2005, the instrument was installed on a ferryboat commuting between Helsinki (Finland) and Travemünde (Germany), and data were collected during 32 transects providing altogether 200 000 fluorescence records. PC in vivo fluorescence was compared with Chla in vivo fluorescence and turbidity measured simultaneously, and with Chla concentration and biomass of the bloom forming filamentous cyanobacteria determined from discrete water samples.PC fluorescence showed a linear relation to the biomass of the bloom forming filamentous cyanobacteria, and the other sources of PC fluorescence are considered minor in the open Baltic Sea. Estimated by PC fluorescence, cyanobacterial bloom initiated late June at the Northern Baltic Proper, rapidly extended to the central Baltic Proper and the Gulf of Finland, and peaked in the mid-July with values up to 10 mg l−1 (fresh weight). In late July, bloom vanished in most areas.During single transects, or for the whole summer, the variability in Chla concentrations was explained more by PC fluorescence than by Chla fluorescence. Thus, filamentous cyanobacteria dominated the overall variability in phytoplankton biomass. Consequently, we show that during the cyanobacterial blooms, the estimation of Chla concentration using only Chla in vivo fluorescence is not applicable, but PC in vivo fluorescence is required as a predictor as well. 相似文献
4.
吕宋海峡西部深海盆内孤立波潜标观测研究 总被引：6，自引：2，他引：4
HU Zifeng TAN Yehui SONG Xingyu ZHOU Linbin LIAN Xiping HUANG Liangmin HE Yinghui 《海洋学报(英文版)》2014,33(3):118-128
Mesoscale eddies have been suggested to have an impact on biological carbon fixation in the South China Sea （SCS）. However, their overall contribution to primary production during the spring inter-monsoon pe riod is still unknown. Based on large-scale biological and environmental in situ observations and synchro nous remote sensing data, the distribution patterns of phytoplankton biomass and the primary production, and the role of mesoscale eddies in regulating primary production in different eddy-controlled waters were investigated. The results suggested that the surface chlorophyll a concentrations and water column inte grated primary production （IPP） are significantly higher in cyclonic eddies and lower in the anticyclonic eddies as compared to that in non-eddy waters. Although eddies could affect various environmental factors, such as nutrients, temperature and light availability, nutrient supply is suggested to be the most important one through which mesoscale eddies regulated the distribution patterns of phytoplankton biomass and pri mary production. The estimated IPP in cyclonic and anticyclonic eddies are about 29.5% higher and 16.6% lower than the total average in the whole study area, respectively, indicating that the promotion effect of mesoscale cold eddies on the primary production was much stronger than the inhibition effect of the warm eddies per unit area. Overall, mesoscale eddies are crucial physical processes that affect the biological car bon fixation and the distribution pattern of primary production in the SCS open sea, especially during the spring inter-monsoon period. 相似文献
5.
Donald M. Anderson 《Ocean & Coastal Management》2009,52(7):342-347
Virtually every coastal country in the world is affected by harmful algal blooms (HABs, commonly called “red tides”). These phenomena are caused by blooms of microscopic algae. Some of these algae are toxic, and can lead to illness and death in humans, fish, seabirds, marine mammals, and other oceanic life, typically as a result of the transfer of toxins through the food web. Sometimes the direct release of toxic compounds can be lethal to marine animals. Non-toxic HABs cause damage to ecosystems, fisheries resources, and recreational facilities, often due to the sheer biomass of the accumulated algae. The term “HAB” also applies to non-toxic blooms of macroalgae (seaweeds), which can cause major ecological impacts such as the displacement of indigenous species, habitat alteration and oxygen depletion in bottom waters.Globally, the nature of the HAB problem has changed considerably over the last several decades. The number of toxic blooms, the resulting economic losses, the types of resources affected, and the number of toxins and toxic species have all increased dramatically. Some of this expansion has been attributed to storms, currents and other natural phenomena, but human activities are also frequently implicated. Humans have contributed by transporting toxic species in ballast water, and by adding massive and increasing quantities of industrial, agricultural and sewage effluents to coastal waters. In many urbanized coastal regions, these inputs have altered the size and composition of the nutrient pool which has, in turn, created a more favorable nutrient environment for certain HAB species. The steady expansion in the use of fertilizers for agricultural production represents a large and worrisome source of nutrients in coastal waters that promote some HABs.The diversity in HAB species and their impacts presents a significant challenge to those responsible for the management of coastal resources. Furthermore, HABs are complex oceanographic phenomena that require multidisciplinary study ranging from molecular and cell biology to large-scale field surveys, numerical modelling, and remote sensing from space. Our understanding of these phenomena is increasing dramatically, and with this understanding comes technologies and management tools that can reduce HAB incidence and impact. Here I summarize the global HAB problem, its trends and causes, and new technologies and approaches to monitoring, control and management, highlighting molecular probes for cell detection, rapid and sensitive toxin assays, remote sensing detection and tracking of blooms, bloom control and mitigation strategies, and the use of large-scale physical/biological models to analyze past blooms and forecast future ones. 相似文献
6.
大气校正是水体定量遥感的基础与前提。本文从大气校正模型、大气校正模型参数、水体组分差异以及水深反演波段组合方式4个维度探讨大气校正模型对水深反演的影响。研究采用6S、FLAASH、ACOLITE与QUAC 4种大气校正模型,选取大陆型、海洋型与城市型气溶胶模式,以瓦胡岛西北侧与谢米亚岛周边浅水作为清洁水体研究区,以辽东浅滩与槟城海峡作为浑浊水体研究区,基于Landsat-8多光谱影像开展大气校正,并采用8种波段组合方式进行水深遥感反演。研究结果表明:（1）4种大气校正模型均可在一定程度上削弱大气对水体信号的影响;因参数选取以及研究区水体组分的不同,不同模型的校正结果存在一定差异;两类水体反射率峰值分别出现在蓝波段与绿波段;（2）6S大气校正模型鲁棒性较强,该模型因研究区水体组分发生变化导致对应的水深反演结果与其余模型相比波动较小;FLAASH模型在海洋型和城市型两种气溶胶模式水深反演结果在浑浊水体存在较为明显的差异,辽东浅滩浅水区平均相对误差相差7.9%;ACOLITE模型受水体类型影响显著且对浑浊水体具有优越性与稳定性,平均相对误差较FLAASH降低5.6%;（3）多波段水深反演精度普遍优于单波段,但反演精度与波段数目之间无显著的相关性;水深反演波段组合方式对不同研究区敏感性不同,清洁水体三波段模型的反演精度较好,浑浊水体中四波段模型的反演精度最优,平均相对误差较三波段模型降低达5.6%。 相似文献
7.
The wintertime ratio of inorganic dissolved nitrogen to phosphorus (DIN/DIP) in the surface waters of the Baltic Sea is typically below the molar Redfield ratio of 16, which expresses the presence of an excess inorganic dissolved phosphorus (eDIP) reserve compared to DIN. We assessed the role of the vernal phytoplankton bloom period (VPBP) in the consumption of the potential wintertime eDIP reserve, and the role of eDIP after the VPBP as a nutritional agent for the summertime growth of the cyanobacteria in the Baltic Sea. We employed a high-frequency dataset collected by the unattended monitoring systems on board merchant ships. The dataset encompasses the Baltic basins from the Arkona Basin to the Western Gulf of Finland and the time period from 1993 to 2009. All the observed values of the wintertime DIN/DIP ratio were below the molar Redfield ratio; the ratio showed a declining trend during the study, suggesting that there is a pronounced wintertime stock of the potential eDIP in the waters of the Baltic Sea, and that this stock has lately increased in magnitude. The VPBP took up excessively DIP to DIN than calculated according to the uptake in the molar Redfield ratio, thus reducing the potential eDIP reserve. On average, 59% of the potential eDIP reserve was left in the water after the VPBP as eDIP. eDIP was typically exhausted in the time frame early June–early July, matching well the timing of the appearance of cyanobacteria in substantial numbers in the water-column. eDIP clearly fueled the cyanobacterial growth in every instance in which it was possible to clarify their relationship. The cyanobacteria must still have another DIP source than eDIP to form extensive late-summer blooms, except in the western Gulf of Finland, where eDIP remained detectable up to early August. The annual role of eDIP for cyanobacterial growth depends greatly on the weather of late spring and early summer: this may sometimes launch the cyanobacterial growth much earlier than is usually expected. 相似文献
8.
《Deep Sea Research Part I: Oceanographic Research Papers》2005,52(6):979-999
The study establishes an annual estimate for annual primary production of 81 g C m−2 for the open Greenland Sea based on data from five cruises and literature data. This estimate agrees well with a model estimate based on nutrient utilisation but is a factor of 2–5 less than published primary production estimates made by remote sensing of this area. The seasonal distribution of particulate primary production in open Greenland Sea waters followed the seasonal distribution of surface irradiance with a peak in June, indicating that light is the primary factor governing primary production in the area. At stations along the ice edge, blooms were recorded in both June and August, suggesting a pattern of repeated blooms during the summer season at the ice edge. Subsurface phytoplankton peaks were a persistent feature in the open Greenland Sea from May to August. These peaks were consisted of actively photosynthesising phytoplankton and up to 90% of total water column particulate primary production was estimated to occur in association with these peaks. Diatoms dominated the phytoplankton community during the spring bloom and in the Polar Water during August. Size distribution analyses of the phytoplankton communities indicated that the relative abundance of large cells compared to small cells was greatest in May as compared to June and August. No significant differences were noted between June and August in the slope of the phytoplankton size distribution spectra. Inorganic nitrogen and phosphorus nutrients were measurable in surface waters on all cruises. Only in August were there some indications (altered Redfield ratios and higher nutrient concentrations in subsurface chlorophyll peaks than at the surface) of nutrient depletion of surface waters. Implications for food web structure and carbon flux of these patterns in phytoplankton activity and distribution are discussed. 相似文献
9.
Review and suggestions for estimating particulate organic carbon and dissolved organic carbon inventories in the ocean using remote sensing data 总被引：2，自引：0，他引：2
Dissolved organic carbon（DOC） and particulate organic carbon（POC） are basic variables for the ocean carbon cycle.Knowledge of the distribution and inventory of these variables is important for a better estimation and understanding of the global carbon cycle.Owing to its considerable advantages in spatial and temporal coverage,remote sensing data provide estimates of DOC and POC inventories,which are able to give a synthetic view for the distribution and transportation of carbon pools.To estimate organic carbon inventories using remote sensing involves integration of the surface concentration and vertical profile models,and the development of these models is critical to the accuracy of estimates.Hence,the distribution and control factors of DOC and POC in the ocean first are briefly summarized,and then studies of DOC and POC inventories and flux estimations are reviewed,most of which are based on field data and few of which consider the vertical distributions of POC or DOC.There is some research on the estimation of POC inventory by remote sensing,mainly in the open ocean,in which three kinds of vertical profile models have been proposed：the uniform,exponential decay,and Gauss models.However,research on remote-sensing estimation of the DOC inventory remains lacking.A synthetic review of approaches used to estimate the organic carbon inventories is offered and the future development of methods is discussed for such estimates using remote sensing data in coastal waters. 相似文献
10.
黄河口悬浮泥沙时空动态及其驱动机制 总被引：1，自引：1，他引：0
受径流输沙、风浪、潮汐等影响,河口近岸海域悬浮泥沙具有显著的时空变化。本文基于小时分辨率的GOCI遥感影像,利用最优遥感反演算法,结合空间分析和统计方法,深入研究黄河口及邻近海域悬沙时空动态特征及驱动机制。结果表明,径流输沙对悬沙浓度的影响以河口近岸区为主,高径流输沙对悬沙浓度分布影响可达距岸约20 km,并向孤东近岸方向扩散。大风可引起清水沟老河口区泥沙强烈再悬浮,形成高浓度悬沙区。涨落潮对小时尺度的悬沙浓度影响显著,并影响悬沙的南北扩散。大潮悬沙浓度变化和扩散范围均大于小潮,潮流流速不同是造成该差异的主要原因。水深与悬沙浓度之间存在较明显的负相关关系,根据不同驱动因素的差异,悬沙浓度随着水深的增加呈现出指数型、幂函数型、线性3种关系。 相似文献
11.
Max M. Tilzer 《新西兰海洋与淡水研究杂志》2013,47(3):401-412
In eutrophic lakes cyanobacteria are favoured relative to other phytoplankton, both under stratified and mixed conditions. During stratification, gas vacuole formation allows the accumulation of dense surface scums which attain the highest possible area‐specific photosynthetic rates in aquatic environments owing to high irradiances, near‐complete harvesting of impinging light, and minimal light inhibition and photo‐oxidation. During moderate mixing, high yields of biomass can be achieved by effective light harvesting for photosynthesis (aided by phycobilin pigments) and low maintenance energy requirements at low mean irradiances. Howevrr, nitrogen fixation competes for energy and reductant with photosynthesis, and leads to a decline of light‐saturated maximum growth rates. Wind‐driven vertical mixing and lateral advection are the main causes for the instability of cyanobacterial blooms in hyper‐eutrophic lake ecosystems. 相似文献
12.
An automatic measuring system called “FerryBox” was installed in the North Sea on a ferry travelling between Germany (Cuxhaven) and Great Britain (Harwich), enabling online oceanographic and biological measurements such as salinity, temperature, fluorescence, turbidity, oxygen, pH, and nutrient concentrations. Observations made along the ferry transect reveal characteristic phenomena such as high salinity inflow through the Channel into the Southern Bight, algal bloom dynamics and related oxygen and pH changes. Combination of these online observations with remote sensing enhances the spatial resolution of the transect related measurements. Several examples of the synergy between these two measuring strategies are shown, both for large-scale algal blooms in the North Sea as well as for local intense but short-term blooms in the German Bight. Coherence of the data sets can be gained and improved by using water transport models in order to obtain synoptic overviews of the remotely sensed and FerryBox related parameters. Limitations of the currently used algorithms for deriving chlorophyll-a from remote sensing images for coastal and shelf seas (Case-2 water) are discussed, as well as depth related processes which cannot be properly resolved on the basis of water intake at a fixed point. However, in unstratified coastal waters under normal conditions FerryBox data represent average conditions. The importance of future applications of this combination of methods for monitoring of coastal waters is emphasized. 相似文献
13.
悬浮泥沙作为重要水质参数，其分布和动态变化对河口及近岸的生态、环境、物质循环等都具有深远的影响。我国静止轨道高分四号(GF-4)卫星数据具有高时间和高空间分辨率的观测优势，在水色遥感上具有重大应用潜力。为探究GF-4卫星对悬浮泥沙浓度的监测能力，本文以杭州湾为研究区，构建反演模型，利用静止海洋水色成像仪进行交叉验证。结果表明，以GF-4卫星第5和第4波段遥感反射率的比值作为遥感因子建立的反演模型精度较高，决定系数为0.92，均方根误差为223.2 mg/L，平均相对误差为17.2%。交叉验证结果显示，GF-4卫星作为一种新的遥感数据源，在低浓度区与静止海洋水色成像仪反演悬浮泥沙浓度分布相似，但在高浓度区的差异随浓度增高而增大，总体可满足中国大部分海区的监测需求。 相似文献
14.
Remote sensing of chlorophyll concentration is potentially affected by the presence of inorganic matter in the water column. Seasonal variability of total suspended particulate matter (SPM) concentration and its partition into organic and inorganic fractions was thus measured in the estuary and Gulf of St. Lawrence during five cruises. These measures were made in the surface layer down to the depth of the 0.1% light level. Results indicate that vertical variability was small for the entire study area. Data analysis lead to the definition of two main regions having different SPM characteristics: 1) the estuary zone characterized by a strong spatial variability, intermediate SPM concentrations and a clear spring phytoplankton bloom that is combined to an increased inorganic matter load; 2) the gulf region characterized by a relatively low SPM concentration and phytoplankton blooms in the spring and fall periods. Combined with in situ measurements of remote sensing reflectances, the database was used to validate existing inorganic matter retrieval algorithms and develop a new one better adapted to the low concentrations encountered in the St. Lawrence estuary and Gulf. 相似文献
15.
In 2002–2008, seasonal (April–November) monitoring of the phytoplankton in the Russian part of the Curonian Lagoon at five fixed sites was performed. A total of 91 Cyanobacteria, 100 Bacillariophyta, 280 Chlorophyta, 21 Cryptophyta, and 24 Dinophyta species were found. Six potentially toxic species of cyanobacteria: Aphanizomenon flos-aquae, Anabaena sp., Microcystis aeruginosa, M. viridis, M. wesenbergii, and Planktothrix agardhii dominated the phytoplankton biomass and caused water blooms. The seasonal average phytoplankton biomass ranged from 30 to 137 g/m3. The cyanobacteria’s biomass varied from 10 to 113 g/m3 forming 30–82% of the total with a mean of 50%. With the aid of genetic markers (microcystin (mcy) and nodularin synthetases), six variants of the microcystin-producing gene mcyE from the genus Microcystis were identified. Due to the intensive and lengthy blooms of potentially toxic and toxigenic cyanobacteria, the environmental conditions in the Curonian Lagoon appear unfavorable. The water should be monitored for cyanotoxins with analytical methods in order to determine if the area is safe for recreational use. 相似文献
16.
2009年冬、夏季南海北部超微型浮游生物的分布特征及其环境相关分析 总被引：2，自引：1，他引：1
2009年2月(冬季)和8月(夏季)在南海北部海域(nSCS)采用流式细胞术对聚球藻、原绿球藻、超微型光合真核生物3类超微型光合浮游生物和异养浮游细菌的丰度和碳生物量的时空分布特征进行了研究,并分析了其与环境因子之间的关系。结果表明,夏季聚球藻和原绿球藻的平均丰度高于冬季,超微型光合真核生物和异养浮游细菌的丰度反之,为冬季高于夏季。聚球藻、超微型光合真核生物和异养浮游细菌在富营养的近岸陆架海域丰度较高,而原绿球藻高丰度则出现在陆坡开阔海域。在垂直分布上,聚球藻主要分布在跃层以上,跃层以下丰度迅速降低;原绿球藻高丰度主要出现在真光层底部;超微型光合真核生物在水层中的高值同样出现在真光层底部,且与Pico级份叶绿素a浓度分布一致;异养浮游细菌在水体中的分布与聚球藻类似。这些分布格局的差异,取决于环境条件的变化和4类超微型浮游生物生态生理适应性的差异。在超微型光合浮游生物群落中,各类群碳生物量的贡献因季节和海域类型的不同而发生变化:聚球藻在夏季近岸陆架区占超微型光合浮游生物总碳生物量的41%,原绿球藻在陆坡开阔海成为主要贡献者(50%),超微型光合真核生物碳生物量以冬季为高(在近岸陆架区占比68%)。冬、夏季异养浮游细菌碳生物量均高于超微型光合浮游生物碳生物量。 相似文献
17.
An extremely dense bloom of the potentially toxic dinoflagellate Alexandrium tamarense was observed in the lagoons of Cà Pisani (Veneto, Italy) in summer 1993. The lagoons were experiencing a significant eutrophication impact, receiving waste waters from intensive fish culture plants. During their bloom dinoflagellates in the lagoons reached densities of 2 to 4 × 106 cells·dm−3 and a biomass of over 100 g·m−3. The bloom produced drastic ecological changes in the lagoons. It caused nocturnal anoxia, mortality of macrophytes and the build-up of labile organic matter in the water column. Grazing by the tintinnid Favella sp. contributed to the termination of the bloom of the flagellates. The results show that coastal aqua culture probably stimulates dinoflagellate blooms in shallow brackish lagoons. 相似文献
18.
19.
海草生长在热带、亚热带和温带海洋水域, 是全球海洋生态系统中重要的结构和功能组成部分, 具有极高的生态服务价值。由于受到人类活动和自然灾害的强烈影响, 海草正在全球范围内快速衰退, 因此开展海草资源监测与保护具有非常重要的意义。随着传感器技术的发展, 光学遥感在海草监测中表现出卓越优势。本文综述了国内外海草遥感监测研究现状, 重点总结了研究内容、技术和方法, 论证了海草光学遥感监测的可行性, 旨在为我国海草光学遥感监测厘清适宜数据和可靠技术方法, 并指明潜在研究方向。同时也希望能为海草遥感监测提供借鉴, 并拓展海草资源科学管理的思路。 相似文献
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漫衰减系数是一个重要的海洋光学参数,能够为水体环境变化、水质分析以及水产养殖等方面提供基础性数据。针对目前船载实地测量效率与分辨率低、卫星遥感反演精度与分辨率较低的局限性,本文提出一种基于机载LiDAR测深水体波形的漫衰减系数提取方法。该方法首先通过分层异构模型的机载LiDAR波形分解算法得到水体散射回波,利用激光在水体中的衰减特性,构建漫衰减系数提取模型,最终获取大面积水域漫衰减系数的空间分布。采用西沙甘泉岛与江苏连云港两个航次的实测数据对所提算法进行了验证,本算法无需每个测深点的水底底部回波强度和深度即可反演得到漫衰减系数,并且在浑浊水域也可取得较好的效果,表明在中国近海利用机载LiDAR测深系统能够有效获取高精度的漫衰减系数。 相似文献