Alaska SeaLife Center, PO Box 1329, Seward, AK 99664, USA.
Aquat Toxicol. 2018 Jun;199:220-231. doi: 10.1016/j.aquatox.2018.04.002. Epub 2018 Apr 7.
Increasing oil development around Alaska and other Arctic regions elevates the risk for another oil spill. Dispersants are used to mitigate the impact of an oil spill by accelerating natural degradation processes, but the reduced hydrophobicity of dispersed oil may increase its bioavailability to marine organisms. There is limited research on the effect of dispersed oil on cold water species and ecosystems. Therefore, spiked exposure tests were conducted with bay mussels (Mytilus trossulus) in seawater with non-dispersed oil, Corexit 9500 and oil dispersed with different concentrations of Corexit 9500. After three weeks of exposure, acute and chronic physiological impacts were determined. The majority of physiological responses occurred during the first seven days of exposure, with mussels exhibiting significant cytochrome P450 activity, superoxide dismutase activity and heat shock protein levels. Mussels exposed to non-dispersed oil also experienced immune suppression, reduced transcription and higher levels of mortality. After 21 days, mussels in all treatments exhibited evidence of genetic damage, tissue loss and a continued stress response. Bay mussels are useful as indicators of ecosystem health and recovery, and this study was an important step in understanding how non-dispersed oil, dispersant and dispersed oil affect the physiology of this sentinel species in Arctic/subarctic conditions.
随着阿拉斯加和其他北极地区的石油开发不断增加，再次发生石油泄漏的风险也在上升。分散剂被用于通过加速自然降解过程来减轻石油泄漏的影响，但分散后的石油疏水性降低可能会增加其对海洋生物的生物利用度。关于分散后的石油对冷水物种和生态系统的影响，研究还很有限。因此，在海水中进行了带有海湾贻贝（Mytilus trossulus）的加标暴露测试，海水中含有未分散的石油、Corexit 9500 和用不同浓度的 Corexit 9500 分散的石油。暴露三周后，测定了急性和慢性生理影响。大多数生理反应发生在暴露的前七天，贻贝表现出明显的细胞色素 P450 活性、超氧化物歧化酶活性和热休克蛋白水平。暴露于未分散的石油中的贻贝也经历了免疫抑制、转录减少和更高的死亡率。21 天后，所有处理组的贻贝都表现出遗传损伤、组织损失和持续的应激反应的证据。海湾贻贝是评估生态系统健康和恢复的有用指标，本研究是了解非分散油、分散剂和分散油如何影响北极/亚北极条件下这种指示物种生理机能的重要一步。
