Li Meihui, Sun Geng, Qiu Jiangbing, Li Aifeng
College of Environmental Science and Engineering, Ocean University of China, Qingdao, 266100, China.
College of Environmental Science and Engineering, Ocean University of China, Qingdao, 266100, China; Key Laboratory of Marine Environment and Ecology, Ocean University of China, Ministry of Education, Qingdao 266100, China.
Toxicon. 2017 Mar 1;127:1-10. doi: 10.1016/j.toxicon.2016.12.009. Epub 2016 Dec 22.
Lipophilic shellfish toxins (LSTs) produced by diverse microalgae have become a potential threat to the marine aquaculture industry in coastal regions throughout the world. In this study, phytoplankton, scallop, and seawater samples were collected and monitored in the aquaculture zone of Liuqing Bay located in the coast of Qingdao, Yellow Sea, in 2014 and 2015. Dissolved LSTs in seawater were adsorbed by solid phase adsorption toxin tracking (SPATT) bags and solid phase extraction (SPE) cartridges, respectively. PTX2 was found to be the predominant LSTs, while OA and DTX1 were detected at trace levels in the three species of Dinophysis and Phalacroma genera picked from the investigation zone. The highest quota of PTX2 occurred in D. fortii (0.28 pg cell), followed by D. acuminata complex (0.08 pg cell) and P. rotundatum (=D. rotundata) (0.02 pg cell). PTX2 (nd∼5.7 μg kg), OA (nd∼2.8 μg kg) and DTX1 (nd∼1.6 μg kg) were also observed in cultivated scallops, but in addition to the former, PTX2sa, 7-epi-PTX2sa and an isobaric form of DTX1 suspected as DTX1b were also found in the SPATT bags. The isobaric compound of DTX1 only appeared in the SPATT bags deployed in field samples of seawater. A significant higher quantity of OA was adsorbed by SPATT bags compared to DTX1, although similar concentrations of both toxins were adsorbed by SPE cartridges from the aquaculture zone. AZA2 was also found in the concentrated phytoplankton cells, which demonstrated that AZA-producing microalgae were present in this investigated area. The variation in concentrations of PTX2 adsorbed by SPATT bags could reflect the change of Dinophysis density in seawater, but there was a time lag behind the peaks of Dinophysis density. Comparative results did not support the SPATT technology as a useful warning tool for toxic algal blooms and toxin accumulation in bivalves. The data suggest that the contamination of LSTs was prevalent in the coast of Qingdao and the environmental behavior of LSTs should be explored further.
由多种微藻产生的亲脂性贝类毒素（LSTs）已对全球沿海地区的海水养殖业构成潜在威胁。本研究于2014年和2015年在黄海青岛海岸的柳清湾养殖区采集并监测了浮游植物、扇贝和海水样本。海水中溶解的LSTs分别通过固相吸附毒素追踪（SPATT）袋和固相萃取（SPE）柱进行吸附。发现PTX2是主要的LSTs，而在从调查区域采集的三种双鞭藻属和圆筛藻属物种中检测到痕量水平的OA和DTX1。PTX2的最高含量出现在强渐尖鳍藻（0.28 pg/细胞）中，其次是渐尖鳍藻复合种（0.08 pg/细胞）和圆筛藻（=旋转双鞭藻）（0.02 pg/细胞）。在养殖扇贝中也观察到PTX2（未检出～5.7 μg/kg）、OA（未检出～2.8 μg/kg）和DTX1（未检出～1.6 μg/kg），但除了前者外，在SPATT袋中还发现了PTX2sa、7-表-PTX2sa和一种疑似DTX1b的DTX1等压异构体。DTX1的等压化合物仅出现在部署于海水现场样本的SPATT袋中。与DTX1相比，SPATT袋吸附的OA量显著更高，尽管来自养殖区的SPE柱吸附的两种毒素浓度相似。在浓缩的浮游植物细胞中也发现了AZA2，这表明该调查区域存在产生AZA的微藻。SPATT袋吸附的PTX2浓度变化可以反映海水中双鞭藻密度的变化，但在双鞭藻密度峰值之后存在时间滞后。比较结果不支持将SPATT技术作为有毒藻华和双壳贝类毒素积累的有效预警工具。数据表明，LSTs污染在青岛海岸普遍存在，LSTs的环境行为应进一步探索。
