长江口及其邻近海域有害藻华的发生情况、危害效应与演变趋势   总被引：3，自引：0，他引：3  

于仁成  张清春  孔凡洲  周正熙  陈振帆  赵越  耿慧霞  代丽  颜天  周名江 《海洋与湖沼》2017,48(6):1178-1186

长江口及其邻近海域是我国近海有害藻华高发区之一。自2000年以来,由东海原甲藻(Prorocentrum donghaiense)、米氏凯伦藻(Karenia mikimotoi)和亚历山大藻(Alexandrium spp.)等甲藻形成的大规模有害藻华连年暴发,对海水养殖业、人类健康和生态安全构成了严重威胁。以往调查和研究工作表明,长江口及其邻近海域藻华优势类群近年来已由硅藻逐渐转变为甲藻,同时,有害藻华原因种也表现出明显的年际变异特征和有毒有害藻种增多的态势,亟待解析其演变机理、趋势和驱动因素。长江口及其邻近海域受长江径流影响,富营养化问题突出,是大规模有害藻华形成的重要原因。同时,该海域也受到来自台湾东北部黑潮分支的影响,但对其与有害藻华的关系所知甚少。在中国科学院战略性先导科技专项"热带西太平洋海洋系统物质能量交换及其影响"支持下,针对这一问题开展了较为系统的调查和研究工作,本文对研究中得到的科学认识进行了初步总结。结果表明:东海黑潮分支能够到达长江口及其邻近海域赤潮区,影响该海域赤潮生物多样性状况;黑潮分支对长江口及其邻近海域甲藻赤潮发生过程具有重要调控作用;长江冲淡水和黑潮分支的共同作用决定了长江口及其邻近海域有害藻华的发生过程和演变趋势。在现有结果基础上进一步分析和讨论了未来长江口及其邻近海域有害藻华的研究方向,以期为进一步解析有害藻华演变趋势、提升有害藻华的监测和预警能力提供依据。  相似文献   

Biosorption of Uranium Ions by Marine Macroalga Padina pavonia          下载免费PDF全文

Sule Aytas  Elif Gunduz  Cem Gok 《洁净——土壤、空气、水》2014,42(4):498-506

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海洋中型浮游动物的选择性摄食对浮游植物群落的控制   总被引：5，自引：0，他引：5  

王小冬  孙军  LIU Dong-yan  刘东艳  汪岷 《海洋科学进展》2005,23(4):524-535

海洋中型浮游动物的选择性摄食很大程度上影响着浮游植物种群的变化,控制着海洋初级生产力的节律、规模和归宿。从海洋中型浮游动物选择性摄食对有害藻华的控制、中型浮游动物的选择性摄食机制、中型浮游动物选择性摄食的研究方法和中型浮游动物的选择性摄食模型四个方面探讨了中型浮游动物选择性摄食对控制浮游植物种群演替的贡献,为进一步预测和控制有害藻华发生提供科学依据。  相似文献   

三沙市南海诸岛底栖海藻区系调查及其与其它相关区系的比较分析   总被引：1，自引：0，他引：1  

夏邦美  王广策  王永强 《海洋与湖沼》2013,44(6):1677-1704

我国海岸线绵长,所属岛屿众多,除了台湾岛和海南岛两个大岛外,还有数以千计的中小沿海岛屿及众多的珊瑚岛,如我国三沙市的南海诸岛—西沙群岛、南沙群岛、东沙群岛和中沙群岛等。根据多年来我国科研人员在该海区的调查研究,对我国三沙市南海诸岛海区的海藻区系进行初步的植物地理学研究,以探讨我国该海域海藻区系的温度性质,以及与邻近海区海藻区系的关系。研究结果表明,我国三沙市南海诸岛底栖海藻区系与北太平洋西部海藻相同种数最多的是区系性质为热带性的南海南区,因此海藻区系的温度性质具有很明显的热带性。另外,三沙市南海诸岛海藻区系与印度洋海藻区系有很多共同成分,两地共有种数高达184种,为南海诸岛海藻总数的63%,进一步证明我国三沙市南海诸岛区系属于暖水性印度—西太平洋区,印—马亚区。  相似文献   

Light‐dependence of photosynthesis and growth in cyanobacteria: Implications for their dominance in eutrophic lakes     

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   

The genus Pseudo-nitzschia (Bacillariophyceae) in New Zealand: analysis of the last decade's monitoring data     

L Rhodes  W Jiang  B Knight  J Adamson  K Smith  V Langi 《新西兰海洋与淡水研究杂志》2013,47(4):490-503

The diatom genus Pseudo-nitzschia blooms throughout New Zealand's coastal waters. More than a decade of monitoring data were analysed in this study and seasonality was a significant factor in the appearance of Pseudo-nitzschia blooms. Austral spring and summer were the main bloom periods, although there were regional differences. Between January 2000 and August 2011, 8.4% of 29,000 seawater samples analysed for Pseudo-nitzschia exceeded the voluntary trigger level for biotoxin testing (10×10⁴ cells l^?1), and these were analysed by fluorescent in situ hybridisation (FISH) assays. Pseudo-nitzschia fraudulenta and P. pseudodelicatissima (low domoic acid [DA] producers) were the dominant bloom formers throughout New Zealand (each contributing 25%) followed by the highly toxic P. australis (10%). Shellfish flesh testing for DA was triggered on 8477 occasions between 2000 and 2011, but no samples exceeded the regulatory limit (20 mg/kg); the maximum concentration was 13 mg/kg (Marlborough Sounds, mid-winter 2010).  相似文献   

Molecular iodine (I2) emission from two Laminaria species (Phaeophyceae) and impact of irradiance and temperature on I2 emission into air and iodide release into seawater from Laminaria digitata     

《Marine environmental research》2013

Kelps of the genus Laminaria accumulate iodine at high concentrations, but the iodine retaining capacity can be affected by emersion and physiological stress. In this study, I₂ emission into the atmosphere from Laminaria digitata and Laminaria hyperborea was compared under controlled low irradiances and temperatures. The two species exhibited different I₂ emission rates as blades of L. digitata emitted I₂ at rates five times higher than those from newly-grown blades (current growth season) of L. hyperborea. I₂ emission was not detectable from old blades (previous growth season) of L. hyperborea. Additionally, effects of irradiance and temperature on both I₂ emission into air and net I⁻ release into seawater where assessed for L. digitata while monitoring photo-physiological parameters as stress indicators. Irradiances between 30 and 120 μmol photons m⁻² s⁻¹ had only marginal effects on both I₂ emission and I⁻ release rates, but physiological stress, indicated by photoinhibition, was observed. The results suggest that the irradiances applied here were not stressful enough to impact on the iodine release. By contrast, at elevated temperatures (20 °C), photoinhibition was accompanied by an increase in I₂ emission rates, but net I⁻ release rates remained similar at 10–20 °C. High I₂ emission rates into air and I⁻ release into seawater observed from L. digitata underpin the fundamental function of this kelp as mediator of coastal iodine fluxes.  相似文献   

Food web structure within kelp holdfasts (Laminaria): a stable isotope study     

Gauthier Schaal  Pascal Riera  Cédric Leroux 《Marine Ecology》2012,33(3):370-376

Kelp holdfasts are highly reticulated structures which host a large diversity of small fauna. These microhabitats have been reported to play a crucial role in the biodiversity associated to kelp forest ecosystems. This study aimed at identifying trophic links and the main food sources sustaining food webs within communities associated with kelp holdfasts, through a stable isotope (δ¹³C and δ¹⁵N) approach. Sampling of the main invertebrates inhabiting Laminaria digitata holdfasts, and of their potential food sources, took place in February and May 2007. Stable isotope results reveal that most of the primary consumers, including filter-feeders and deposit-feeders, rely on the particulate organic matter sedimented within kelp holdfasts. Only three grazers departed from this general pattern. The correspondence between the stable isotope ratios of predators and sediment consumers indicated that this source is at the base of the main pathway through which energy and matter transit in the food web. δ¹⁵N ranges found for consumers revealed that the food web associated with kelp holdfasts is composed of 3.5 levels. In spite of the low diversity of food sources at the base of the food web, these microhabitats can therefore be considered micro-scale ecosystems, from a functional perspective.  相似文献   

Pigment characterization for the 2011 bloom in Qinhuangdao implicated "brown tide" events in China   总被引：6，自引：0，他引：6  

孔凡洲  于仁成  张清春  颜天  周名江 《中国海洋湖沼学报》2012,30(3):361-370

A large-scale bloom occurred from May to June in 2011 in sea area near Qinhuangdao of the Bohai Sea, leading to huge damage of the scallop culture industry. Similar blooms have been observed in this region for three years. The causative species of the bloom, which dominated the phytoplankton community with the maximum cell density around 109 cell/L, could not be identified with morphological features due to the small cell size (~2 mm). A pigment analytical method was then adopted to analyze the pigment profile of the phytoplankton samples collected from the blooming sea area. It was found that pico-sized (<2 mm), nano-sized (2-20 mm), and bulk phytoplankton samples had similar pigment profile, representing the pigment signature of the bloom-causative species. The major pigments detected included 19-butanoyloxyfucoxanthin (But-fuco), fucoxanthin (Fuco), diadinoxanthin (Diad) and chlorophyll a (Chl a), and high content of But-fuco was the most significant characteristics of the phytoplankton samples. Based on the pigment composition and content, the bloom-causative species could be tentatively identified as pelagophyte, "type 8" group of haptophyte, or silicoflagellate. Some unique features of the bloom, such as the extremely high cell density, small-sized and But-fuco containing cells, occurring in early summer, and the feeding-cessation effects on scallops, suggest it be a "brown tide" event similar to those reported in the east coast of the United States of America. The recurrent "brown tide" events and their dramatic impacts on the shellfish mariculture industry in Qinhuangdao need close attention in the coming years.  相似文献   

The benefits and challenges of Collective and Creative Storytelling through visceral methods within the neoliberal university: Debate title: Better than text? Critical reflections on the practices of visceral methodologies in human geography     

《Geoforum》2017

This contribution describes three phenomenon regarding visceral methods. It highlights the importance of collaborative data creation, and the opportunity of creativity to produce pleasure, laughter, as well as to see and sense power. But it also demonstrates the danger posed by the neoliberal university to the further development and implementation of visceral methods.  相似文献