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1.
横山水库浮游植物群落结构季节性变化特征   总被引:3,自引:0,他引:3       下载免费PDF全文
分析了2010-2011年不同季节横山水库浮游植物群落结构的变化特征.结果表明,4个季节共采集到90种(属)浮游植物,蓝藻和硅藻在横山水库浮游植物季节性演替中的作用非常重要.在太湖流域首次发现拟柱胞藻(Cylindrospermopsis sp.),夏季在水库成为优势种并引起水华,密度达到1.01×108个/L.富营养化日趋严重的横山水库为拟柱胞藻水华奠定了基础.作为生态入侵种,拟柱胞藻可以产生毒素,危害生态系统和人体健康.应加强监测和流域综合管理,防止拟柱胞藻水华扩散到流域内其它大型水库.  相似文献
2.
藻类水华会释放大量毒素和有害物质,造成水生生物的大量死亡,给渔业生态环境带来严重危害。生物控制措施可以在一定程度上降低水体富营养化程度和控制藻类的过度繁殖,防止有害藻类大量爆发。主要生物控制作用包括,一方面促进水体生态系统的物质循环和能量流动,加速营养元素沉降或脱离水生生态系统;另一方面限制或抑制水华藻类的生长,使水体生态系统处于稳定的动态平衡。  相似文献
3.
文章通过对常见丝状藻类及其形成藻华形态的描述,综述丝状藻藻华的形成条件及危害,说明各种水体中控制丝状藻藻华的必要性和紧迫性,概述了常见控制藻类药物和药物的致毒机理,为丝状藻类及其藻华的控制提供参考。  相似文献
4.
杨志远  徐虹 《水产养殖》2012,33(4):17-19
通过对2008年5月发生在连云港海州湾海域的一次赤潮异弯藻赤潮的跟踪监测,并研究其赤潮发生与环境因子的关系,得出:良好的水文气象条件,丰富的营养盐为赤潮的爆发及维持提供了基础。赤潮的发生,导致pH值、盐度、溶解氧、叶绿素a、营养盐等环境因子都发生了变化。此次赤潮异弯藻赤潮主要吸收硝酸盐和铵盐,磷酸盐是其生长的限制因子。高氮磷比也是赤潮异弯藻生长的重要调控因子。  相似文献
5.
继甲藻赤潮、浒苔绿潮的暴发后,2011年中国又一种新的海洋灾害——褐潮(brown tide)被首次确认,中国成为继美国和南非之后第三个出现褐潮的国家。褐潮对我国沿海养殖业、渔业资源、生态环境以及人类健康构成了重大的危害和威胁,严重影响了沿海经济。因此加强与褐潮相关的生态学与海洋学研究,探索褐潮的发生机制,并建立监测网络,进行褐潮预警预报,对减少褐潮的危害,保障我国沿海经济的持续发展,具有十分重要意义。  相似文献
6.
ABSTRACT:   The amount of microcystin in Microcystis aeruginosa bloom was investigated during the rainy season of 1999 in Laguna de Bay, the Philippines. Bloom samples taken from the West Bay and East Cove stations of the lake were studied in relation to the characteristics of environmental conditions. Four types of microcystins, microcystin-LR (MC-LR), microcystin-RR (MC-RR), 6(Z)-Adda-microcystin-RR, and 3-desmethylmicrocystin-LR were identified from the natural bloom samples among which MC-LR was the most dominant type of microcystin. Production of microcystin (88.6 µg/100 mg dried cells) was highest during the first sampling week that coincided with high water transparency and high conductivity. The occurrence of a strong typhoon during the second sampling week had changed the environment drastically, which was characterized by low water transparency, high turbidity, low water temperature, and with trace amounts of MC-LR detected at the East Cove station. Thus, toxin production over time as well as the relationship between Microcystis production and toxin concentration could not be fully evaluated.  相似文献
7.
8.
This study was conducted to gain insight into the characteristics of algal blooms in relation to the marine environment of Gamak Bay. From the first known occurrence of algal blooms in 1984 until 2006, 23 causal species have been identified, the most common ones being Prorocentrum sp., Cochlodinium polykrikoides, Chaetoceros sp., Skeletonema costatum, and Heterosigma akashiwo. A principal component analysis indicated that blooms of these species develop under different conditions in terms of water temperature, salinity, precipitation, and insolation. Field data showed Cochlodinium polykrikoides to be favored by high temperatures and to be euryhaline, whereas Skeletonema costatum appeared to be eurythermal and euryhaline. Prorocentrum sp. and Chaetoceros sp. appeared to be stenothermal and stenohaline. Finally, Heterosigma akashiwo appeared at the lowest temperature and highest salinity of the five species and was classified here as stenothermal and stenohaline.  相似文献
9.
Abstract:   Heterosigma akashiwo virus (HaV) is a large icosahedral virus (∼0.2 μm) harboring a double-stranded DNA (dsDNA) genome (∼294 kbp). The virus is the only member of the genus Raphidovirus in the family Phycodnaviridae. Since its first discovery, a number of ecologic, physiologic and genetic studies about HaV have been conducted; especially, the relationship between H. akashiwo and HaV in nature was studied and viral infection is now regarded as a significant factor influencing the dynamics and termination of H. akashiwo blooms. HaV infection has considerable impacts on H. akashiwo populations in both aspects of fluctuation in biomass (quantity) and changes in clonal composition (quality). Partial sequencing of the HaV genome revealed that a number of genes showed considerable similarity to those of other protist-infecting viruses; still, the phylogenetic position of HaV suggested a number of enigmas in host–virus coevolution. Here are summarized the ecology, physiology and genetics of HaV especially from the viewpoint of the host–virus relationship.  相似文献
10.
阳澄湖是江苏省重要的淡水湖泊之一,全湖分为东、中、西3个湖区。近年来阳澄湖内加大了鲢(Hypophthalmichthys molitrix)、鳙(Aristichthys nobilis)的控藻力度,西湖藻华消失,而中湖和东湖仍偶有藻华出现。为了比较3个湖区水质和浮游植物的差异,在3个湖区分别布设南、北2个采样位点,于2017年夏季、秋季及2018年春季采集水样进行鲢鳙控藻效应分析。结果表明,阳澄湖3个湖区总氮(TN)、总磷(TP)均达到劣Ⅴ类水质标准,营养盐浓度由西向东逐渐下降。西湖3个季节叶绿素a(Chl-a)浓度都低于15 μg/L,透明度最高。调查期间共发现浮游植物8门、77属、177种,其中西湖种类数最少,仅有8门、59属、105种。从浮游植物多样性看,阳澄湖水质处于轻污染状态。西湖浮游植物细胞密度年均(3.50 ± 0.49) × 106 个/L,分别约为中湖和东湖的1/10和1/4。中湖和东湖于夏、秋季检出超富营养化(ɑ-ps)指示藻类,但西湖三季均未检测到。2017年10月,西湖鲢鳙存鱼密度分别为中湖的3.8倍和东湖的2.3倍,规格和肠道饱满度指数显著低于中湖和东湖(P< 0.05)。研究显示,现阶段阳澄湖藻华发生与否不完全由营养盐水平决定,可能与鲢鳙牧食藻类有关。  相似文献
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