USDA APHIS National Wildlife Research Center, Fort Collins, CO, United States.
Department of Animal Science, Michigan State University, East Lansing, MI, United States.
Ecotoxicol Environ Saf. 2017 Dec;146:83-90. doi: 10.1016/j.ecoenv.2017.07.018. Epub 2017 Aug 16.
The explosion of the Deepwater Horizon oil rig released, millions of gallons of oil into the environment, subsequently exposing wildlife, including numerous bird species. To determine the effects of MC252 oil to species relevant to the Gulf of Mexico, studies were done examining multiple exposure scenarios and doses. In this study, laughing gulls (Leucophaeus atricilla, LAGU) were offered fish injected with MC252 oil at target doses of 5 or 10mL/kg bw per day. Dosing continued for 27 days. Of the adult, mixed-sex LAGUs used in the present study, ten of 20 oil exposed LAGUs survived to the end of the study; a total of 10 of the oil exposed LAGUs died or were euthanized within 20 days of initiation of the study. Endpoints associated with oxidative stress, hepatic total glutathione (tGSH), oxidized glutathione (GSSG) and reduced glutathione (rGSH) significantly increased as mean dose of oil increased, while the rGSH:GSSG ratio showed a non-significant negative trend with oil dose. A significant increase in 3-methyl histidine was found in oil exposed birds when compared to controls indicative of muscle wastage and may have been associated with the gross observation of diminished structural integrity in cardiac tissue. Consistent with previous oil dosing studies in birds, significant changes in liver, spleen, and kidney weight when normalized to body weight were observed. These studies indicate that mortality in response to oil dosing is relatively common and the mortality exhibited by the gulls is consistent with previous studies examining oil toxicity. Whether survival effects in the gull study were associated with weight loss, physiologic effects of oil toxicity, or a behavioral response that led the birds to reject the dosed fish is unknown.
深水地平线石油钻井平台爆炸，数百万加仑的石油流入环境，随后暴露了野生动物，包括许多鸟类。为了确定 MC252 石油对与墨西哥湾相关的物种的影响，进行了多项暴露情景和剂量的研究。在这项研究中，给笑鸥（Leucophaeus atricilla，LAGU）投喂注射了 MC252 石油的鱼，目标剂量为每天 5 或 10mL/kg bw。给药持续 27 天。在本研究中，使用的成年混合性别 LAGUs 中，有 20 只中的 10 只暴露于油的 LAGUs 存活到研究结束；共有 10 只暴露于油的 LAGUs 在研究开始后的 20 天内死亡或被安乐死。与氧化应激相关的终点、肝总谷胱甘肽（tGSH）、氧化谷胱甘肽（GSSG）和还原谷胱甘肽（rGSH）随着油平均剂量的增加而显著增加，而 rGSH：GSSG 比值与油剂量呈负相关趋势。与对照组相比，暴露于油的鸟类中 3-甲基组氨酸显著增加，表明肌肉消耗，可能与心脏组织结构完整性明显减少的大体观察有关。与鸟类以前的油剂量研究一致，观察到肝、脾和肾重量与体重标准化时显著变化。这些研究表明，对油剂量的反应导致的死亡率相对较高，而海鸥表现出的死亡率与以前研究检查的石油毒性一致。在海鸥研究中，生存效应是否与体重减轻、石油毒性的生理效应或导致鸟类拒绝投喂鱼的行为反应有关尚不清楚。
