中国北部沿海有毒鳍藻产毒特征及其与贝类染毒关系的研究

Previous detection results indicated that cultured shellfish contaminated by Dirrahetic Shellfish Poisoning(DSP) has been found frequently and widely in China. Toxic Dinophysis spp. in genus Dinophysis were the main source of DSP in shellfish, and they were able to pollute shellfish even in low density.Thus, there is an urgent need for researching on toxin production and population dynamics of toxic Dinophysis spp. from coastal area of our country. This research will be mainly executed by adopting field ecological investigation, synthesizing advanced image collection &. analysis technology, molecular biological methods and chemical analysis technology with high sensitivity. Selecting the north region of China Sea as research area, where the distribution of toxic Dinophysis spp. and shellfish contaminated by DSP were reported. We will study the seasonal, regional and interannual change characteristics of toxin composition and content in Dinophysis spp., to reveal the toxin prodution disciplinarian and the interspecific differences. Different species of Dinophysis spp. will be identified and the seasonal, regional and interannual change characteristics of Dinophysis spp. populaiton will be investigated to find out their population dynamics disciplinarian. The process of DSP contaminating shellfish during Dinophysis spp. bloom will also be studied, to clarify the relationship between toxic Dinophysis spp. and shellfish contaminated by DSP, and to extimate the influence from toxic Dinophysis spp. to the safety of aquatic products. The systematically research of this program on the toxin production characteristic, population dynamics of Dinophysis spp. and its influence to the safety of cultured shellfish in the north region of China Sea, will provides scientific evidence and make suggestions to effectively monitor and prevent poisoning events of DSP for relevant department, and also supply useful scientific methods for deeply understanding the forming and damage mechanism of toxic Dinophysis spp. bloom.

已有检测结果表明，我国沿海养殖贝类沾染腹泻性贝毒的情况非常严重。鳍藻属中的有毒种类在低密度下就可以导致贝类沾染腹泻性贝毒，故亟需系统开展针对我国沿海有毒鳍藻产毒特征和种群动态的研究。本项目将主要通过野外生态调查，综合图像采集分析技术、分子生物学技术和高灵敏度化学分析技术，选择有鳍藻分布和贝类染毒事件报道的中国北部沿海区域作为目标海域，研究鳍藻的毒素组成及含量的季节性、地域性和年际变化特征，揭示其产毒规律和种间差异性；研究不同种类鳍藻种群密度和分布的季节性、地域性和年际变化特征，探明其种群动态规律；研究养殖贝类在鳍藻水华发生期间的染毒过程，阐明有毒鳍藻对养殖贝类食品安全的影响。本项目针对中国北部沿海区域鳍藻产毒特征、种群动态及对养殖贝类食品安全影响开展的系统研究，将为有效监测、预防腹泻性贝毒中毒提供科学依据和建议，并为深入研究鳍藻藻华的形成机制和危害机理提供科学研究方法。

由沾染腹泻性贝毒（Diarrhetic Shellfish Poisoning, DSP）的水产品所导致的人类中毒事件在沿海各国均有报道。已有的检测结果表明，我国沿海贝类沾染DSP毒素的情况非常严重，甚至已有相关中毒事件发生的报道，应当引起相关部门的重视。本项目主要通过野外生态调查，综合形态学特征分析、分子生物学技术和高灵敏度的化学分析技术，选择有鳍藻分布和贝类染毒报道的中国北部沿海区域作为目标海域，研究了鳍藻的毒素组成及含量的季节性变化特征；同时，对海域中包括DSP毒素在内的多种常见脂溶性毒素进行了分析，研究了其地域性、季节性变化规律；研究了养殖贝类在鳍藻高密度值期间的染毒情况，探讨了有毒鳍藻对养殖贝类食品安全的影响。研究结果显示，我国北部沿海海域，包括青岛胶州湾、大连獐子岛和烟台四十里湾均有鳍藻分布，其种类主要有渐尖鳍藻复合种（Dinophysis acuminata species complex）、圆形鳍藻（D.rotundata）、倒卵形鳍藻（D. fortii）。鳍藻的种群密度呈现季节性变化规律，但表现出一定的种间差异性。影响鳍藻种群动态的环境因子主要有温度（T）、总磷（P）、硝酸盐（NO3-N）和亚硝酸盐（NO2-N），但不同种类鳍藻对环境因子的响应表现出一定的差异。利用高灵敏度的超高效液相联用技术从手工挑取的鳍藻细胞中检测到蛤毒素2（Pectenotoxin-2，PTX2）毒素，其含量呈现一定的季节性差异。同时，从所有调查海域中都检测到多种脂溶性毒素，除了常见的DSP毒素，包括大田软海绵酸（Okadaic acid，OA）、鳍藻毒素1（Dinophysistoxin-1，DTX1）外，还有PTX2、虾夷扇贝毒素（Yessotoxin，YTX）和环亚胺毒素（Gymnodimine，GYM）。从典型调查海域鳍藻密度高值期的多数养殖扇贝体内检测到PTX2毒素，可能来源于鳍藻，另外仅从1个样品中检出OA毒素。此外海域中还可能存在其他产毒藻类，需要继续开展相关研究工作。综上所述，本项目针对中国北部沿海区域鳍藻产毒特征、种群动态及对养殖贝类食品安全影响开展了系统研究，为有效监测、预防腹泻性贝毒中毒事件提供了科学依据和建议，为深入研究鳍藻藻华的形成机制和危害机理提供了科学的研究方法。