Brannon Ernest L, Collins Keya M, Cronin Mathew A, Moulton Lawrence L, Parker Keith R, Wilson William
Center for Salmonid and Freshwater Species at Risk, Aquaculture Research Institute, University of Idaho, Moscow, Idaho 83844-2260, USA.
Environ Toxicol Chem. 2007 Apr;26(4):780-6. doi: 10.1897/06-414r.1.
It has been hypothesized that pink salmon eggs incubating in intertidal streams transecting Prince William Sound (PWS) beaches oiled by the Exxon Valdez oil spill were exposed to lethal doses of dissolved hydrocarbons. Since polycyclic aromatic hydrocarbon (PAH) levels in the incubation gravel were too low to cause mortality, the allegation is that dissolved high-molecular-weight hydrocarbons (HPAH) leaching from oil deposits on the beach adjacent to the streams were the source of toxicity. To evaluate this hypothesis, we placed pink salmon eggs in PWS beach sediments containing residual oil from the Exxon Valdez oil spill and in control areas without oil. We quantified the hydrocarbon concentrations in the eggs after three weeks of incubation. Tissue PAH concentrations of eggs in oiled sediments were generally < 100 ppb and similar to background levels on nonoiled beaches. Even eggs in direct contact with oil in the sediment resulted in tissue PAH loads well below the lethal threshold concentrations established in laboratory bioassays, and very low concentrations of HPAH compounds were present. These results indicate that petroleum hydrocarbons dissolved from oil deposits on intertidal beaches are not at concentrations that pose toxic risk to incubating pink salmon eggs. The evidence does not support the hypothesis that interstitial pore water in previously oiled beaches is highly toxic.
据推测，在横切威廉王子湾（PWS）海滩的潮间带溪流中孵化的粉鲑卵，因埃克森·瓦尔迪兹号油轮漏油事件而受到油污影响，接触到了致死剂量的溶解碳氢化合物。由于孵化砾石中的多环芳烃（PAH）水平过低，不足以导致死亡，有人认为从溪流附近海滩上的油沉积物中浸出的溶解高分子量碳氢化合物（HPAH）是毒性来源。为了评估这一假设，我们将粉鲑卵放置在含有埃克森·瓦尔迪兹号油轮漏油事件残留油污的PWS海滩沉积物中，以及没有油污的对照区域。孵化三周后，我们对卵中的碳氢化合物浓度进行了量化。受油污沉积物中卵的组织PAH浓度一般<100 ppb，与未受油污海滩的背景水平相似。即使是直接与沉积物中的油接触的卵，其组织PAH含量也远低于实验室生物测定中确定的致死阈值浓度，且HPAH化合物的浓度非常低。这些结果表明，从潮间带海滩上的油沉积物中溶解出来的石油碳氢化合物浓度，不会对正在孵化的粉鲑卵构成毒性风险。证据不支持以前受油污海滩中的间隙孔隙水具有高毒性这一假设。
