首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 31 毫秒
1.
Abstract. Red tides of the toxic dinoflagellate Pyrodinium bahamense var. compressum have occurred almost annually since 1976 in the coastal waters of the west coast of Sabah, Malaysia. Field obSérvations have indicated that the timings of these outbreaks could be linked to meteorological forcings. All the red tides have occurred during either the northeast or southwest monsoon periods. Matching of red tide outbreaks with total monthly rainfall, monthly-averaged index of wind-induced surface water mixing, and monthly-averaged upwelling index for the period from 1975 to 1989 failed to show any definite pattern. However, more red tide events occurred in months with high mixing index values. The absence of definable patterns could be due to the use of monthly, rather than daily, values in the calculations.  相似文献   

2.
文章收集整理2010—2020年发生在宁德近岸海域的赤潮事件,综合分析该海域赤潮的时空分布和种类特征,结果表明:(1)近11年来宁德近岸海域共发生赤潮16起,年均1.5起;总面积高达1 468 km2,年均133.5 km2;持续时间共169天,年均15.4天。(2)从月份上看,赤潮发生在4—6月,高发期为5月。(3)发生赤潮的种类共有3种甲藻和1种硅藻,其中发生次数、面积和持续天数最高的均为东海原甲藻,其次为米氏凯伦藻,最低为中肋骨条藻。(4)从空间分布上来看,福宁湾及其周边海域(A区)赤潮次数和持续天数最长,三沙湾外海域(D区)赤潮面积最大,三沙湾内海域(C区)的赤潮种类最多。(5)米氏凯伦藻引发的有毒赤潮共4次,主要集中在霞浦近岸海域。适宜的温度、盐度、丰富的营养盐和良好的天气是米氏凯伦藻形成赤潮的前提条件。  相似文献   

3.
福建沿岸海域主要赤潮生物的生态学特征   总被引:5,自引:0,他引:5  
许翠娅  黄美珍  杜琦 《台湾海峡》2010,29(3):434-441
福建沿岸海域是中国的赤潮多发海区之一.据统计,1962~2008年间,福建沿岸海域共发生赤潮180起以上,潜在的赤潮生物有124种,已经引发过赤潮的种类有27种.本文对中肋骨条藻(Skeletonema costatum)、角毛藻(Chaetocerosspp.)、夜光藻(Noctiluca scintillans)、东海原甲藻(Proro-centrum donghaiense)、米氏凯伦藻(Karenia mikimotoi)、裸甲藻(Gymnodinium spp.)和球形棕囊藻(Phaeocystis globosa)等福建沿岸海域主要赤潮生物的生态学特征和发生原因进行了分析和探讨,评述了福建沿岸海域赤潮发生的特点.福建沿岸海域引发赤潮频率最高的赤潮生物是夜光藻,米氏凯伦藻造成的水产养殖损失最大.其赤潮多发季节在春夏季的4~7月.其赤潮多发区主要分布在3个区域:宁德沿岸海域(以四礵列岛为中心)、厦门西港海域和平潭沿岸海域.对福建沿岸海域几种主要赤潮生物的研究表明,赤潮的发生与水温、盐度、气象、水动力、营养盐等环境条件密切相关.  相似文献   

4.
浙江近岸海域赤潮发生的趋势与特点   总被引:5,自引:0,他引:5  
根据历史记载和近年调查实测资料,概述了浙江近岸海域赤潮的历史与现状,分析了赤潮的特点与发生趋势,研究结果表明:浙江近岸海域各种不同类型藻类引发的赤潮频率均呈上升趋势,其中甲藻赤潮的发生次数上升尤为迅速,赤潮出现的规模越来越大,有毒赤潮记录次数也显著增加。探讨了赤潮发生的一些原因,指出了建立科学评估有害赤潮影响体系和预警系统的意义并提出了一些对策措施与建议。  相似文献   

5.
样品于1987年2月至1988年2月采集于珠江口水域。从珠江口水域鉴定出26种赤潮生物,分析了赤潮生物的季节更替现象,讨论赤潮生物与温度、盐度、营养盐的关系。  相似文献   

6.
收集2000—2018 年福建近岸海域224 次赤潮事件资料,通过综合分析结果表明:2000—2018 年福建近岸海域赤潮发现数量和面积分别占全国的17.3%和6.1%。2015—2018 年相对于2000—2004、2005—2009、2010—2014 年赤潮年均发现数量和面积有明显下降。赤潮发现月份和空间特征明显,5—6 月为高发期;宁德、福州、平潭、厦门、泉州海域是赤潮高发区;4 个时间段比较宁德和厦门海域年均发现赤潮数量下降明显,平潭海域略微下降,泉州海域增加。由甲藻门生物引发的赤潮数量、面积和损失均最高,诱发赤潮的生物类群存在南北差异,有毒赤潮占总赤潮数量的14.3%。根据提出的赤潮等级划分标准,福建近岸海域以小型赤潮为主。建议在宁德至平潭近岸海域、泉州近岸海域加强赤潮立体化监测系统的建设,5—6 月为监测的关键时期。  相似文献   

7.
文章通过收集《广东省海洋灾害公报》中2013—2022年的赤潮灾害数据,运用统计学方法对近10年广东省海域的赤潮灾害时空分布等基本特征进行综合分析,以期为赤潮灾害的预警、防治等工作提供参考依据。分析结果表明:时间分布上,近10年间广东省海域共发生赤潮95次,年平均9.5次,共发生面积3 624.76 km2,主要发生时间集中在1-4月,平均每次赤潮持续时间为8.8 d;空间分布上,赤潮发生次数最多的主要位于珠三角海域,赤潮面积发生最大的则位于粤西海域。引发赤潮的生物共有26种,其中硅藻门13种、甲藻门10种、定鞭藻门、黄藻门和原生动物门各1种,引发赤潮次数最多的是夜光藻和红色赤潮藻,引发赤潮面积最大的是球形棕囊藻,近年来引发赤潮的生物种类呈现多样化的趋势。  相似文献   

8.
在全球气候变化和人类活动加剧的背景下,赤潮、绿潮、褐潮、水母暴发和泥螺入侵等生态灾害已成为近年来海洋生态系统异常的主要表现形式。为科学管理和防治山东近岸海域生态灾害,文章汇总1999-2018年山东近岸海域典型生态灾害的特征和变化趋势。研究结果表明:赤潮是山东近岸海域最主要的生态灾害,研究期内共发生赤潮69起,累计面积为7 141 km2,发生海域主要集中在滨州-东营近岸、潍坊小清河口、莱州近岸、长岛近岸、烟台四十里湾、青岛胶州湾、威海乳山近岸和日照近岸,以夜光藻为主;自2007年以来,绿潮在我国南黄海海域每年均有发生,持续时间70余天,此外烟台套子湾、四十里湾和蓬莱近岸以及潍坊近岸等海域也相继发生绿潮,主要种类包括缘管浒苔、石莼、管浒苔和束生刚毛藻;褐潮是由抑食金球藻引起的生态灾害,山东近岸海域仅2011年和2012年有褐潮发生;水母暴发种主要包括海月水母、沙海蜇和白色霞水母,其中海月水母是山东半岛近岸海域种群数量最大、分布范围最广和暴发频率最高的种类;泥螺入侵是由于2001年的人为引种而导致的生物入侵灾害,近年来泥螺数量大幅减少,目前仅在滨州、东营和潍坊局部潮间带有少量分布。  相似文献   

9.
相较于船舶走航监测, 海洋水质浮标在线监测的优势在于能够获取目标海域长期、连续监测数据, 能更好地反映环境状况的动态变化。为了厘清米氏凯伦藻赤潮的发生、发展动态, 本文以2017年6月南麂附近海域米氏凯伦藻赤潮为例, 分析海洋水质浮标获取的连续监测数据, 探讨米氏凯伦藻赤潮过程叶绿素a和水环境因子动态变化特征及其与气象要素的关系。赤潮期间, 水温为22.8~26.0℃、盐度为28.8‰~31.8‰、气温为20.4~27.3℃, 该温盐范围均适宜米氏凯伦藻的细胞生长; 较高的光照强度能够支持较高的藻类细胞密度。Pearson相关性分析显示, 米氏凯伦藻细胞密度与叶绿素a浓度呈显著正相关; 溶解氧(DO)及其饱和度(DO%)、pH、水温、气温等环境因子与叶绿素a浓度呈极显著正相关, 盐度与叶绿素a浓度呈极显著负相关。向岸风生海流有利于藻种向近岸较高营养区域汇集, 为赤潮的爆发创造有利条件。赤潮过程中, 叶绿素a浓度、溶解氧饱和度、pH发生了协同变化, 据此特征可以开展赤潮短期预警。  相似文献   

10.
To distinguish true red tide water (particularly Cochlodinium polykrikoides blooms) from non-red tide water (false satellite high chlorophyll water) in the South Sea of Korea, we developed a systematic classification method using spectral information from MODIS level products and applied it to five different harmful algal bloom events. Red tide and nonred tide waters were classified based on four different criteria. The first step revealed that the radiance peaks of potential red tide water occurred at 555 and 678 nm. The second step separated optically different waters that were influenced by relatively low and high contributions of colored dissolved organic matter (CDOM) (including detritus) to chlorophyll. The third and fourth steps discriminated red tide water from non-red tide water based on the blue-to-green ratio in areas with lower and higher contributions of CDOM to chlorophyll, respectively. After applying the red tide classification (using the four criteria), the spectral response of the red tide water, which is influenced by pigment concentration, showed different slopes for the blue and green bands (lower slope at blue bands and higher slope at green bands). The opposite result was found for non-red tide water, due to decreasing phytoplankton absorption and increasing detritus/CDOM absorption at blue bands. The results were well matched with the discoloration of water (blue to dark red/brown) and delineated the areal coverage of C. polykrikoides blooms, revealing the nature of spatial and temporal variations in red tides. This simple spectral classification method led to increase user accuracy for C. polykrikoides and non-red tide blooms (>46% and >97%) and provided a more reliable and robust identification of red tides over a wide range of oceanic environments than was possible using chlorophyll a concentration, chlorophyll anomaly, fluorescence analysis, or proposed red tide detection algorithms.  相似文献   

11.
使用《天津市海洋环境状况公报》中的数据,分析天津沿海赤潮发生的特征。通过分析发现2005-2017年天津海域共发生赤潮30次,累计发生面积4 695 km2。天津沿海赤潮发生主要集中在夏季,又以8月最多,占赤潮发生总数的30%。通过赤潮优势种的分析发现近年来天津海域赤潮生物的优势种类有不断增加的趋势。同时本文从水文气象条件诱发赤潮的角度分析得出了天津沿海最易发生赤潮的天气形势,天津沿海25~27℃水温范围内赤潮发生较多,最适宜赤潮发生的风速为3、4级风,风向为东南风、西南风。  相似文献   

12.
长江口海域是我国的一个典型水域,具有很高的浮游植物物种多样性,其中包括很多种赤潮物种,引起赤潮频发.本文总结了过去40年间长江口海域历次航次调查的研究结果,比较分析了52个航次调查鉴定的浮游植物组成,重点探索了赤潮物种的组成,并详细描述了长江口海域的6种典型赤潮物种:中肋骨条藻、东海原甲藻、旋链角毛藻、夜光藻、米氏凯伦...  相似文献   

13.
浙江沿岸的赤潮灾害及防治对策   总被引:4,自引:0,他引:4  
浙江沿岸海域是我国沿岸赤潮灾害的多发区之一。统计表明,在过去的60年间,浙江沿岸曾有34次赤潮记载。赤潮已对浙江近海的渔业和养殖业构成严重威胁。文章简要地分析了赤潮形成的几种可能原因,指出浙江沿岸海域随时都可能发生大面积赤潮。为此。笔者呼吁应加强和重视浙江沿岸赤潮灾害的监测、监视和防治研究工作。提出的几点预防对策,供有关部门参考。  相似文献   

14.
甲藻赤潮与水体中营养盐的关系初探   总被引:8,自引:0,他引:8  
林昱 《台湾海峡》2001,20(1):77-79
作者在国家海洋局第三海洋研究所的陆基水池中,应用围隔实验技术,排除了水动力、盐度等环境因子的变动性的干扰,人工诱发甲藻赤潮.在这个围隔实验的两个围隔体中,分别发生了一种裸甲藻(Gymnodinium sp.)和海洋原甲藻(Prorocentum micans)的赤潮.在赤潮发生和发展过程中所监测到的营养盐数据表明有些甲藻增殖不一定需要水体中高营养盐;营养盐供给的多寡会导致甲藻赤潮优势种的差异和赤潮规模.  相似文献   

15.
Gymnodinium mikimotoi, a senior synonym ofGymnodinium nagasakiense often causes red tides in coastal waters of the western part of Japan. The photosynthetic pigment composition of two strains ofG. mikimotoi were analyzed by HPLC. They contain chlorophyllc 3 which has not been reported from dinoflagellates. They also contain fucoxanthin, 19'-hexanoyloxyfucoxanthin and 19'-butanoyloxyfucoxanthin as major carotenoides, which are anomalous in dinoflagellates. The pigment composition ofG. mikimotoi is compared with that ofGyrodinium aureolum which occur in European waters and is thought as a conspecific species withG. mikimotoi by several authors.  相似文献   

16.
赤潮的爆发是生物、化学、物理等多因素综合作用的结果。温度、风力、风向、气压等气象条件,海况、潮汐、海流及海水的理化特征,如海水温度、盐度、营养盐、微量元素等都是赤潮爆发的重要因子或诱导因素。当前由于海洋生态领域的数值预报仍不成熟,国内的赤潮预测主要还是依靠经验和统计方法为主,如气象条件预报法、水文条件预报法、化学条件预报法、生物条件预报法、卫星遥感预报法或是综合预报法等。本文根据2001年~2005年《沿海海洋赤潮专报》中广东省阳江到汕尾沿海(112°~116°E)即珠江口地区发生赤潮的记录,使用NCEP再分析数据,从气象条件诱发赤潮的角度分析得出最易引发珠江口赤潮的5种天气形势,并用相关性分析方法得出其中两种天气形势的典型场,对预测珠江口沿海的赤潮发生具有一定的指导意义,可在实践中加以应用。  相似文献   

17.
Planktonic mixotrophic and heterotrophic dinoflagellates are ubiquitous protists and often abundant in marine environments. Recently many phototrophic dinoflagellate species have been revealed to be mixotrophic organisms and also it is suggested that most dinoflagellates may be mixotrophic or heterotrophic protists. The mixotrophic and heterotrophic dinoflagellates are able to feed on diverse prey items including bacteria, picoeukaryotes, nanoflagellates, diatoms, other dinoflagellates, heterotrophic protists, and metazoans due to their diverse feeding mechanisms. In turn they are ingested by many kinds of predators. Thus, the roles of the dinoflagellates in marine planktonic food webs are very diverse. The present paper reviewed the kind of prey which mixotrophic and heterotrophic dinoflagellates are able to feed on, feeding mechanisms, growth and ingestion rates of dinoflagellates, grazing impact by dinoflagellate predators on natural prey populations, predators on dinoflagellates, and red tides dominated by dinoflagellates. Based on this information, we suggested a new marine planktonic food web focusing on mixotrophic and heterotrophic dinoflagellates and provided an insight on the roles of dinoflagellates in the food web.  相似文献   

18.
A multi-spectral classification scheme is proposed to identify water with red tide(s) using satellite ocean color imagery obtained by the Sea-viewing Wide Field-of-view Sensor (SeaWiFS). The study area was the eastern Seto Inland Sea in Japan, where serious red tides frequently occur. “Background Ocean Colors” (BOCs hereafter), or colors of water around a red tide or those of the water before/after a red tide, are calculated as the monthly climatological average of normalized water-leaving radiances (nLw) with 0.01 degree spatial resolution with SeaWiFS imagery. Criteria for detecting red-tide pixels are established from analyses of characteristics of the nLws (in the 443, 490, 510, and 555 nm bands) anomalies from BOCs and the nLw spectra together with the red-tide records in Osaka Bay. The proposed scheme can efficiently indicate the presence or absence of red tides for independent match-ups with 83% accuracy. Additional validations of specific events indicate that the algorithm performed well in the study area. These results suggest that the scheme is appropriate to detect red tides in the optically complex coastal water of the eastern Seto Inland Sea.  相似文献   

19.
为进一步加强对赤潮等海洋生态灾害的动态监测,科学支撑海洋防灾减灾工作,文章基于海洋一号D卫星搭载的海岸带成像仪数据,选取北部湾、茂名近岸和陵水湾为研究区域,分析2021年2月发生的4例赤潮事件的遥感影像、叶绿素a浓度和赤潮指数特征。研究结果表明:遥感影像可清晰呈现赤潮分布状况,叶绿素a浓度和赤潮指数的异常值范围与遥感影像一致,赤潮水体的叶绿素a浓度和赤潮指数整体高于非赤潮水体。  相似文献   

20.
The structure and functioning of nanoplanktonic assemblages in coastal upwelling areas have usually been overlooked in explorations of the productivity of these areas. As part of a multidisciplinary, time-series station in the coastal area off Concepción, seasonal variations (upwelling and non-upwelling) in the abundance and biomass of these assemblages were investigated. Hydrographic measurements and biological samples were taken monthly over a 2-year period (18 August 2004-28 July 2006). Nanoflagellates dominated the total integrated abundance (3-317 × 109 cells m−2; 0-80 m). Diatoms and dinoflagellates usually contributed to a lesser degree (<20%) but sporadically made important contributions to the total integrated nanoplankton biomass (0.02-10.6 g C m−2). Most of the nanoplankton was concentrated in surface waters (<30 m) during all the samplings and no seasonal differences in abundance or biomass were found in this layer, although the mean values and dispersions around them were highest during the upwelling period along with maximum integrated (0-80 m) chlorophyll-a values, as total or in the <20 μm fraction. Changes in nanoplankton abundance were significantly but weakly (r < 0.4) correlated with changes in the hydrographic variables; the highest correlation values were positive for temperature and oxygen, factors that varied with depth and date. The potential grazing rates of heterotrophic nano-predators (flagellates and dinoflagellates) on prokaryotic prey, estimated with a generic model, ranged from 3 to 242 bacterioplankton predator−1 h−1 and from 0.1 to 14 cyanobacteria predator−1 h−1. Our results imply a small impact of seasonal hydrographic variability on the abundance and biomass of nanoplanktonic assemblages and suggest that grazing by nanoheterotrophs might control the prokaryotic picoplankton populations in the upwelling area off Concepción.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号