One of the categories of environmental contaminants possibly contributing to declining sockeye salmon (Oncorhynchus nerka) in the Fraser River, British Columbia, Canada is pesticides. In this 4-month study, the effects of environmentally relevant concentrations of a waterborne neonicotinoid, clothianidin (0.15, 1.5, 15 and 150 μg/L), on embryonic, alevin and early swim-up fry sockeye salmon derived from four unique genetic crosses of the Pitt River, BC stock were investigated. There were no significant effects of clothianidin on survival, hatching, growth or deformities, although genetic variation significantly affected these endpoints. Clothianidin caused a significant 4.7-fold increase in whole body 17β-estradiol levels in swim-up fry after exposure to 0.15 μg/L, but no effects were observed on testosterone levels. In addition, hepatic expression of the gene encoding glucocorticoid receptor 2 was also impacted at the highest concentration of clothianidin tested, and was found to be ∼4-fold lower compared to the sockeye reared in control water. These results indicate additional examination of clothianidin and its effects on salmonid gonad development and the reproductive and stress endocrine axes in general, is warranted.

中文翻译：

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新烟碱类可比尼丁对野生早期红鲑鱼（Oncorhynchus nerka）的亚致死作用。

在加拿大不列颠哥伦比亚省的弗雷泽河中，可能导致红鲑鲑（Oncorhynchus nerka）下降的环境污染物之一是农药。在这个为期4个月的研究中，环境相关浓度的水性新烟碱类可尼丁（0.15、1.5、15和150μg/ L）对源自四个独特遗传杂交的胚胎，鱼精和早期游泳鱼苗的红鲑鱼的影响对皮特河（Pitt River）的卑诗省存量进行了调查。尽管遗传变异显着影响了这些终点，但可尼丁对存活，孵化，生长或畸形没有显着影响。暴露于0.15μg/ L后，鱼腥草素可使整个鱼苗的全身17β-雌二醇水平显着增加4.7倍，但未观察到对睾丸激素水平的影响。此外，编码糖皮质激素受体2的基因的肝表达在最高可比甜蛋白浓度下也受到影响，并且与在对照水中饲养的红大黄鱼相比，其表达降低了约4倍。这些结果表明，对噻菌胺及其对鲑鱼性腺发育以及一般生殖和应激内分泌轴的影响进行了进一步检查。