中国赤潮的发生趋势和研究进展

通过对中国沿海赤潮发生历史的回顾以及主要赤潮事件的分析,阐明了中国沿海赤潮发生所呈现的趋势,即频率增加,规模扩大,新的赤潮藻种不断出现,有毒赤潮种比例上升,以及有害赤潮危害程度日益增加,且初步分析了赤潮频发的内因和外因,综述了我国科学家在赤潮生消过程监测,赤潮灌的培养生物学和分类学,赤潮藻类的营养动力学及生理生态学特性,赤潮藻类的生活史,赤潮藻类毒素,赤潮的模型和赤潮防治及国际合作等方面工作的进展,指出了研究还存在的不足之处,并对未来赤潮研究和管理提出了建议。     

中国沿海的赤潮问题

统计了中国沿海１９７２～１９９８年的赤潮事件３６０起（香港、台湾省未统计在内）,系统介绍了中国赤潮研究概况和研究机构与组织。对中国沿海的赤潮进行分海区分析。根据海洋学特征,中国赤潮可分为：近岸型（河口和内湾型）、外海型（外洋型）、外来型（外源型）、养殖区型赤潮。根据中国近十多年来发生赤潮的现状,可归纳为４个特点：①频率增高;②持续时间长、范围广和危害增大;③新记录和有毒种类增多;④“双相型”赤潮有上升趋势、类型多样等。     

广东沿海几种赤潮生物的分类学研究

对１９９７年秋￣１９９８年春广东沿海多次赤潮发生期间的几种优势赤潮藻类进行了形态学和分类学研究。１种为我国首次报道引发赤潮的定革命金藻类（Ｐｒｙｍｎｅｓｉｏｐｈｙｔｅｓ）－球状棕囊藻（Ｐｈａｅｏｃｙｓｔｉｓ ｃｆ．ｇｌｉｏｂｏｓａ）。另有甲藻类７种,其中裸甲藻目（Ｇｙｍｎｏｄｉｎｉａｌｅｓ）３种：米氏裸甲藻（Ｇｙｍｎｏｄｉｎｉｕｍ ｃｆ．ｍｉｋｉｍｏｔｏｉ）、环节环沟藻（Ｇｙｒｏｄｉｎｉｕｍ ｉｎ     

我国近海有害赤潮发生的生态学、海洋学机制及预测防治研究

有害赤潮肆虐于我国和世界各国沿海 ,是国际社会共同关注的重大海洋环境问题和生态灾害 .自 2 0世纪 70年代起 ,我国有记录的赤潮有 4 0 0多次 ,发生次数以每 1 0年增加 3倍的速度上升 ;赤潮发生规模也呈急剧扩大的趋势 ,1 998年至今 ,每年都发生了面积超过 1 0 0 0km2的特大赤潮 ,其中发生在东海舟山附近的原甲藻赤潮的面积达到上万平方公里 ,前后持续时间将近 1个月 ;与此同时 ,有毒、有害的赤潮原因种也在不断增加 ,甲藻等有害种类已成为我国赤潮的主要原因种 ;这些趋势表明了我国赤潮问题的严重性和复杂性 .　　赤潮频发对我国沿海造成…     

南海北部沿海夜光藻赤潮的生态模式研究

本文根据１９８０～１９９１年南海北部沿海发生的夜光藻赤潮资料,介绍了夜光藻的生物学特征．生态学特征,从夜光藻发生赤潮的起始、发展、维持和消亡四个阶段分析和探讨其发生机制,提出了夜光藻赤潮的生态模式。研究表明：夜光藻赤潮各阶段的消长过程受到物理、化学和生物因素的制约．这些因素在夜光藻赤潮发生的不同阶段所起的作用是不一样的,其发生机制仍然存在着生物地理学的差异等。     

赤潮的分类分级标准及预警色设置

为便于赤潮信息的发布、统计和管理,依据我国赤潮发生的特点初步制定了我国赤潮的分类分级及预警色划分的标准。根据形成赤潮的生物种类特性及其对人类健康和近岸水产养殖的影响,将我国赤潮分为有毒赤潮、鱼毒赤潮、有害赤潮和无害赤潮4种类型,考虑到我国沿海赤潮发生面积和持续时间相差巨大,将我国赤潮分为大型、中型和小型3个级别。由此,将我国赤潮分为12种,并依次用不同颜色和符号代表之,以利于在媒体上发布。在此基础上,制定了不同类型赤潮的预警机制和管理措施,为赤潮防灾减灾工作提供参考。     

水华束丝藻NH-5株产生麻痹性贝毒毒素几个相关问题的研究

近年来,有害赤潮在我国沿海养殖区发生越来越频繁,对水产养殖业造成的经济损失越来越严重,并且对人类的健康构成了威胁。引起了我国重视,并开始了研究1、2。有害赤潮所产生的毒素中,麻痹性贝毒毒素在世界范围内分布最广,危害最大,引起人们加倍重视3。由于麻痹性贝毒毒素在国际间的传送受到了严格限制,而我国处于研究起始阶段,缺乏标准毒素,缺乏易于进行培养的赤潮产毒藻株,给研究工作带来了一定困难。一种能产生麻痹性贝毒毒素的淡水蓝藻水华束丝藻NH-5株受到了注意。       

中国东南沿海赤潮发生机理研究已论证通过资助

由暨南大学、中国科学院海洋所、国家海洋局南海分局和中山大学等联合申请的国家自然科学基金重大项目“中国东南沿海赤潮发生机理研究”已论证通过资助。亦潮是由甲藻、硅藻、蓝藻和夜光藻等海洋浮游生物在适宜的条件下,短时间内突发性地大量增殖,密集于海面,使海水相应地变成红色、褐色或其他颜色的一种自然现象。科学家认为赤潮是至今尚难预测的一种海洋生物性的自然灾害。赤潮的危害毒化水质而导致海洋生物大量死亡。如果赤潮恰好发生在水产养殖区、     

近海海洋生态系统与有害赤潮的发生综述

海洋生态系统是地球生物圈的重要组成部分。目前,人类活动已经严重破坏了海洋生态系统,导致了海洋生态系统的失衡。赤潮的发生正是这种不平衡的具体体现。文章讨论了人类活动对海洋生态系统的负面影响以及对近海海域赤潮发生的推波助澜作用;主要综述了影响赤潮发生和消亡的生态条件及环境影响因子。最后,强调了学科交叉研究在管理和防范赤潮的发生,维护近海海洋生态系统健康服务功能的必要性,并提出了一些相应的对策和措施。     

18SrDNA序列分析鉴定棕囊藻香港株P2为球形棕囊藻

有毒赤潮原因种棕囊藻(Phaeocystis sp.)生活史复杂,且形体微小,缺乏明确可靠的分类标准。1997、1999年中国东南沿海发生两次棕囊藻赤潮,但目前种的鉴定仍存在混乱。本文测定了香港海域一株棕囊藻赤潮原因种P₂的18SrDNA部分核苷酸序列,序列长度为650bp,并对其进行了分子鉴定,结果表明其为球形棕囊藻(P.globosa)。     

Characteristics of the membranes of the pellicle of the ciliatePseudomicrothorax dubius

Summary The membranes of the pellicle of the ciliatePseudomicrothorax dubius are investigated using thin section electron microscopy and freeze-fracture replicas. The plasma membrane is covered by a surface coat and is connected to the outer alveolar membrane by short, sometimes branched, bridges. The inner alveolar membrane is coated on both sides. The epiplasm lies in intimate contact with the cytoplasmic surface of this membrane, and there is a corresponding deposit on the other surface. This deposit is regularly striated.The epiplasmic layer and the alveoli are interrupted at sites of cytotic activity,e.g., the attachment sites of trichocysts, the cytoproct, and the parasomal sacs. The striated deposit ends where the epiplasm ends, indicating a direct relationship between these two epimembranous layers.There is a deposit along the sides of the first part of the tip of the trichocysts, and in this region the trichocyst membrane is free of intramembranous particles.The membrane of the parasomal sacs has a coat on both surfaces. That on the extraplasmic surface is similar to the surface coat of the plasma membrane. The origin of the cytoplasmic coat is unknown. The cytotic activity of these sacs is indicated by their highly irregular profiles.     

The early development of the tail and the transformation of the shape of the nucleus of the spermatid of the domestic fowl,Gallus gallus

Summary The differentiation of the spermatid, especially in reference to the formation of the flagellum, and transformation of the shape of the nucleus was investigated in the domestic fowl.In the early stage of the spermatid, a prominent Golgi apparatus appears around the centrioles. The Golgi vesicles then surround the axial-filament complex which develops from the distal centriole. These vesicles fuse to form continuous membrane at the earliest stage of flagellar formation, and in the succeeding stage Golgi lamellae are attached to the plasma membrane of the developing flagellum. From these observations, it is assumed that Golgi apparatus may be a source of the membrane system of the flagellum.The microtubules distributed around the nucleus form the circular manchette. The anterior region of the nucleus with the manchette is cylindrical in shape and the posterior region without it remains irregular in shape. When the circular manchette has been completed, the whole nucleus acquires a slender cylindrical shape. The circular manchette then changes into the longitudinal manchette. The nuclei of spermatids without a longitudinal manchette are abnormal in shape. In view of these observations it is assumed that the nuclear shaping of the spermatid may be accomplished by circular manchette and the maintenance of shape of the elongated nucleus by longitudinal manchette.The authors wish to thank Mr. Takayuki Mori for his helpful suggestions and technical advices     

Characterization of the composition of the aqueous humor and the vitreous body of the eye of the frog Rana temporaria L

This study aimed to analyze the aqueous humor (AH) and the vitreous body (VB) of the eye of the adult frog Rana temporaria L. as a representative species of amphibians, which lead a semi-terrestrial life. The presence of collagen, albumin, uric acid and electron donors was shown in both media; however, there are slight differences in their concentrations. To determine collagen, a spectral-fluorescent probe, cyanine dye, was used. The presence of collagen in AH of the frog was found at the first time. The total content of electron donors (ascorbic and uric acids, tryptophan, and tyrosine) in VB and HA was roughly estimated at ~ 1.5 × 10^− 4 mol/L. Both VB and AH absorb light in similar UV regions. The total protein and albumin contents in AH were found to be somewhat higher than those in VB. The uric acid content was at an equally low level in both intraocular media. It is supposed that the similarity of VB and AH compositions shown in this work is due to some exchange between VB and AH contents in the course of accommodation. The role of intraocular fluids in physiological functions of the eye and in protecting the retina against UV light is discussed.