Pouil Simon, Clausing Rachel J, Metian Marc, Bustamante Paco, Dechraoui-Bottein Marie Yasmine
International Atomic Energy Agency, Environment Laboratories (IAEA-EL), 4a Quai Antoine Ier, MC-98000, Monaco; Littoral Environnement et Sociétés (LIENSs), UMR 7266, CNRS-Université de La Rochelle, 2 rue Olympe de Gouges, F-17000 La Rochelle, France.
International Atomic Energy Agency, Environment Laboratories (IAEA-EL), 4a Quai Antoine Ier, MC-98000, Monaco.
J Environ Radioact. 2018 Dec;192:250-256. doi: 10.1016/j.jenvrad.2018.06.008. Epub 2018 Jul 6.
Marine organisms are exposed to and affected by a multitude of chemicals present in seawater and can accumulate in their tissues a wide range of contaminants as well as natural biotoxins associated with harmful algal blooms (HABs). Trace elements and biotoxins may modify physiological functions in exposed organisms, and studies have been conducted to better understand their respective kinetics and effects in marine species. Despite the increasing concern of concurrent toxic HABs and pollution events due to anthropogenic pressures and global change, very little information is available on their combined effects. Chemical interactions between biotoxins and trace elements have been reported, and exposure to certain biotoxins is known to modify ion transport pathways, suggesting that biotoxins have the potential to alter trace element uptake. Using specific and sensitive radiotracer techniques (radioligand receptor binding assay and γ-spectrometry), this laboratory study examined the influence of pre-exposure to the brevetoxins (PbTxs)-producing microalgae Karenia brevis on the bioaccumulation of selected non-essential (Cd) and essential (Co, Mn and Zn) trace elements in the blue mussel Mytilus edulis. PbTxs are a group of neurotoxins known to accumulate in bivalves but also to have lethal effects on a number of marine organisms including fish and mammals. We found that, over 23 days exposure to the radiotracers, the bioaccumulation of the dissolved essential trace elements Co, Mn and Zn in M. edulis was not significantly affected by pre-exposure to toxic K. brevis. In contrast, the uptake rate constant k of Cd was significantly higher in the pre-exposed group (p < 0.05), likely caused by a decrease in mussel clearance rates after K. brevis exposure. These results suggest that the effects of algal toxin exposure on bioaccumulation of trace elements in mussels may be trace element-dependent.
海洋生物暴露于海水中存在的多种化学物质并受其影响，它们的组织中会积累各种污染物以及与有害藻华（HABs）相关的天然生物毒素。微量元素和生物毒素可能会改变受暴露生物的生理功能，人们已开展研究以更好地了解它们在海洋物种中的各自动力学和影响。尽管由于人为压力和全球变化，有毒藻华和污染事件并发引起的关注日益增加，但关于它们的联合影响的信息却非常少。已报道了生物毒素与微量元素之间的化学相互作用，并且已知暴露于某些生物毒素会改变离子转运途径，这表明生物毒素有可能改变微量元素的摄取。本实验室研究使用特定且灵敏的放射性示踪技术（放射性配体受体结合测定和γ能谱分析），研究了预先暴露于产生短裸甲藻毒素（PbTxs）的微藻短裸甲藻对紫贻贝中选定的非必需（镉）和必需（钴、锰和锌）微量元素生物积累的影响。短裸甲藻毒素是一类神经毒素，已知会在双壳贝类中积累，但也会对包括鱼类和哺乳动物在内的许多海洋生物产生致命影响。我们发现，在暴露于放射性示踪剂的23天期间，预先暴露于有毒短裸甲藻对紫贻贝中溶解的必需微量元素钴、锰和锌的生物积累没有显著影响。相比之下，预先暴露组中镉的摄取速率常数k显著更高（p < 0.05），这可能是由于暴露于短裸甲藻后贻贝清除率降低所致。这些结果表明，藻毒素暴露对贻贝中微量元素生物积累的影响可能因微量元素而异。
