Abstract:
The ecology and life-histories of white sharks make this species susceptible to mercury bioaccumulation; however, the health consequences of mercury exposure are understudied. We measured muscle and plasma total mercury (THg), health markers, and trace minerals in Northwest Atlantic white sharks. THg in muscle tissue averaged 10.0 mg/kg dry weight, while THg in blood plasma averaged 533 μg/L. THg levels in plasma and muscle were positively correlated with shark precaudal length (153-419 cm), and THg was bioaccumulated proportionally in muscle and plasma. Nine sharks had selenium:mercury molar ratios in blood plasma >1.0, indicating that for certain individuals the potential protective effects of the trace mineral were diminished, whereas excess selenium may have protected other individuals. No relationships between plasma THg and any trace minerals or health markers were identified. Thus, we found no evidence of negative effects of Hg bioaccumulation, even in sharks with very high THg.
摘要:
白鲨的生态和生活史使该物种容易受到汞的生物积累;然而,汞暴露对健康的影响研究不足。我们测量了肌肉和血浆总汞(THg),健康标记,以及西北大西洋白鲨中的微量矿物质.肌肉组织中THg平均为10.0mg/kg干重,而血浆中THg平均为533μg/L。血浆和肌肉中THg水平与鲨鱼尾前长度(153-419cm)呈正相关,THg在肌肉和血浆中按比例生物积累。九只鲨鱼的血浆中硒:汞的摩尔比>1.0,这表明对于某些个体,微量矿物质的潜在保护作用减弱,而过量的硒可能保护了其他个体。未鉴定血浆THg与任何微量矿物质或健康标志物之间的关系。因此,我们没有发现汞生物累积的负面影响的证据,即使在鲨鱼中THG很高。