Deblois Charles P, Aranda-Rodriguez Rocio, Giani Alessandra, Bird David F
Département des Sciences Biologiques, Université du Québec à Montréal, P.O. Box 8888, Stn. Centre-Ville, Montréal, Canada.
Toxicon. 2008 Mar 1;51(3):435-48. doi: 10.1016/j.toxicon.2007.10.017. Epub 2007 Nov 6.
The objective of this study was to measure levels of the toxin microcystin in different tissues of fish known to feed on cyanobacteria during toxic bloom events. Wild Nile and redbreast tilapia (Oreochromis niloticus and Tilapia rendalli) were sampled from the catch of artisanal fishermen at eutrophic stations of Funil and Furnas reservoirs in southeastern Brazil. Phytoplankton communities in the two reservoirs were quite different taxonomically, but not dissimilar in microcystin content (200 microg g dry weight (DW) seston(-1) at Funil, 800 microg gDW seston(-1) at Furnas). All of the 27 fish sampled contained microcystin, ranging from 0.8 to 32.1 microg g liver(-1) and from 0.9 to 12.0 ng g muscle(-1). Most microcystin variants found in seston were also found in fish liver. T. rendalli had the lowest concentration in both tissues when compared to O. niloticus. In both reservoirs, one of every four fish sampled, always O. niloticus, had a level of microcystins beyond the World Health Organization tolerable daily intake (8 ng g tissue(-1)) and represented a risk for consumers. It is possible that closer study of inter-species variability in toxin burden in cyanobacteria-impacted water bodies will permit the development of guidelines for fish consumption that will better protect public health.
本研究的目的是测量在有毒水华事件期间以蓝藻为食的鱼类不同组织中的毒素微囊藻毒素水平。野生尼罗罗非鱼和红胸罗非鱼（尼罗罗非鱼和伦氏罗非鱼）从巴西东南部富尼尔和富尔纳斯水库富营养化站点的个体渔民捕捞物中取样。两个水库中的浮游植物群落分类学上差异很大，但微囊藻毒素含量并无不同（富尼尔水库为200微克/克干重（DW）悬浮质（-1），富尔纳斯水库为800微克/克DW悬浮质（-1））。所采样的27条鱼均含有微囊藻毒素，肝脏中含量为0.8至32.1微克/克，肌肉中含量为0.9至12.0纳克/克。在悬浮质中发现的大多数微囊藻毒素变体在鱼肝中也能找到。与尼罗罗非鱼相比，伦氏罗非鱼在这两种组织中的浓度最低。在两个水库中，每四条采样鱼中就有一条（总是尼罗罗非鱼）的微囊藻毒素水平超过世界卫生组织的每日可耐受摄入量（8纳克/克组织（-1）），对消费者构成风险。对受蓝藻影响水体中毒素负荷的种间变异性进行更深入的研究，有可能制定出更好地保护公众健康的鱼类消费指南。
