Following large crude oil spills, oil from feathers of brooding birds and oiled nesting material can transfer to eggs, resulting in reduced embryonic viability for heavily oiled eggs. Eggs may also be subjected to trace or light oiling, but functional teratogenic effects from sublethal crude oil exposure have not been examined. We assessed whether sublethal application of weathered Deepwater Horizon crude oil to the eggshell surface alters heart rate and metabolic rate in Zebra Finch (Taeniopygia guttata) embryos. We first determined sublethal applications with a dosing experiment. Embryo viability for eggs exposed to 5 μL or more of crude oil decreased significantly. We conducted a second experiment to measure heart rate and metabolic rate (CO2 production) 5 and 9 days after 1 sublethal application of crude oil to eggshells on day 3 of incubation. One application of 1.0 or 2.5 μL of crude oil reduced embryonic heart rate and metabolic rate on day 12 of incubation. Using unfertilized eggs, we measured the transfer of polycyclic aromatic hydrocarbons (PAHs) from the eggshell surface to egg contents 8 days after a single application of sublethal crude oil. Our results suggest avian eggs externally exposed to small amounts of crude oil may have protracted embryonic development and impaired postnatal cardiac performance. Article impact statement: Sublethal embryonic effects of crude-oil exposure may impair recovery of bird populations after an oil spill. This article is protected by copyright. All rights reserved.

中文翻译：

---

亚致死应用深水地平线油对鸟蛋胚胎心脏及代谢率的影响

在大量原油泄漏之后，来自育雏鸟类羽毛和沾油的筑巢材料中的油会转移到鸡蛋上，导致严重沾油的鸡蛋的胚胎活力降低。鸡蛋也可能会受到微量或轻油的影响，但尚未研究过亚致死原油暴露引起的功能性致畸作用。我们评估了将风化的深水地平线原油亚致死应用于蛋壳表面是否会改变斑胸草雀（Taeniopygia guttata）胚胎的心率和代谢率。我们首先通过剂量实验确定了亚致死应用。暴露于 5 μL 或更多原油的鸡蛋的胚胎活力显着降低。我们进行了第二个实验，以测量在孵化第 3 天对蛋壳进行 1 次亚致死原油处理后 5 天和 9 天的心率和代谢率（CO2 产量）。在孵化第 12 天，1.0 或 2.5 μL 原油的一次应用降低了胚胎心率和代谢率。使用未受精的鸡蛋，我们测量了单次施用亚致死原油 8 天后多环芳烃 (PAH) 从蛋壳表面转移到鸡蛋内容物的情况。我们的研究结果表明，外部接触少量原油的禽蛋可能会延长胚胎发育并损害出生后的心脏功能。文章影响声明：原油暴露的亚致死胚胎效应可能会损害漏油后鸟类种群的恢复。本文受版权保护。版权所有。我们测量了单次施用亚致死原油 8 天后多环芳烃 (PAH) 从蛋壳表面转移到蛋内的情况。我们的研究结果表明，外部接触少量原油的禽蛋可能会延长胚胎发育并损害出生后的心脏功能。文章影响声明：原油暴露的亚致死胚胎效应可能会损害漏油后鸟类种群的恢复。本文受版权保护。版权所有。我们测量了单次施用亚致死原油 8 天后多环芳烃 (PAH) 从蛋壳表面转移到蛋内的情况。我们的研究结果表明，外部接触少量原油的禽蛋可能会延长胚胎发育并损害出生后的心脏功能。文章影响声明：原油暴露的亚致死胚胎效应可能会损害漏油后鸟类种群的恢复。本文受版权保护。版权所有。原油暴露的亚致死胚胎效应可能会损害漏油后鸟类种群的恢复。本文受版权保护。版权所有。原油暴露的亚致死胚胎效应可能会损害漏油后鸟类种群的恢复。本文受版权保护。版权所有。