缺氧和低盐度会加剧石油暴露对羊头鱼(Cyprinodon variegatus)繁殖的影响。
Hypoxia and reduced salinity exacerbate the effects of oil exposure on sheepshead minnow (Cyprinodon variegatus) reproduction.
机构信息
Department of Pathobiology and Veterinary Science, University of Connecticut, Storrs, CT, USA.
Department of Pathobiology and Veterinary Science, University of Connecticut, Storrs, CT, USA.
出版信息
Aquat Toxicol. 2019 Jul;212:175-185. doi: 10.1016/j.aquatox.2019.05.002. Epub 2019 May 9.
Estuaries of the northern Gulf of Mexico are dynamic environments, with fluctuations in salinity and dissolved oxygen, including areas of seasonal hypoxia. Fish that reside and reproduce in these estuaries, including sheepshead minnow (Cyprinodon variegatus; SHM), were at significant risk of oil exposure following the Deepwater Horizon oil spill. It is poorly understood how differences in environmental conditions during oil exposure impact its toxicity. The present study investigated the effects of crude oil high-energy water accommodated fraction (HEWAF) on SHM reproduction in three environmental scenarios (normoxic, hypoxic, and hypoxic with low salinity) to determine if differences in salinity (brackish vs low salinity) and dissolved oxygen (normoxia vs hypoxia) could exacerbate the effects of HEWAF-derived polycyclic aromatic hydrocarbons (PAHs). We observed that HEWAF exposure significantly increased liver somatic index of SHM compared to control, but this effect was not exacerbated by hypoxia or low salinity. HEWAF exposure also significantly decreased egg production and egg fertilization rate, but only in the hypoxic and hypoxic with low salinity scenarios. A significant correlation existed between body burdens of PAHs and reproductive endpoints, providing substantial evidence that oil exposure reduced reproductive capacity in SHM, across a range of environmental conditions. These data suggest that oil spill risk assessments that fail to consider other environmental stressors (i.e. hypoxia and salinity) may be underestimating risk.
墨西哥湾北部的河口是动态环境,盐度和溶解氧波动较大,包括季节性缺氧区。在深海地平线溢油事件后,生活和繁殖在这些河口的鱼类(包括羊头鲦鱼)面临着巨大的石油暴露风险。人们对石油暴露期间环境条件的差异如何影响其毒性知之甚少。本研究调查了原油高能水可溶部分(HEWAF)在三种环境情景(正常氧、缺氧和低氧低盐)下对羊头鲦鱼繁殖的影响,以确定盐度(半咸水与低盐)和溶解氧(正常氧与缺氧)的差异是否会加剧 HEWAF 衍生多环芳烃(PAHs)的影响。我们观察到,与对照组相比,HEWAF 暴露显著增加了羊头鲦鱼的肝脏体比,但这种影响不受缺氧或低盐的加剧。HEWAF 暴露还显著降低了产卵量和卵受精率,但仅在缺氧和低氧低盐的情况下。PAHs 的体负荷与生殖终点之间存在显著相关性,这为石油暴露降低羊头鲦鱼生殖能力提供了充分的证据,这在一系列环境条件下都是如此。这些数据表明,未能考虑其他环境胁迫因素(即缺氧和盐度)的溢油风险评估可能会低估风险。