Environmental and ecological effects and recoveries after five years of the Hebei Spirit oil spill, Taean, Korea

The Hebei Spirit oil spill (HSOS) in December 7, 2007 spilled approximately 10,900 tons of crude oil in about 10 km off the Taean coasts in South Korea. We first summarize and overview, in the present study, the current status of environmental and ecological effects of the HSOS focusing on i) pollution status for surrounding environment (water, sediment, and porewater), ii) biological effects on living organisms, iii) potential toxic effects in vitro and in vivo, and finally iv) human health risk. In particular, ecological impacts followed by the recoveries of coastal ecosystem are intensively addressed. Water quality seemed to be rapidly recovered considering the background levels of oil pollution indices, while oil impacted sediments experienced fairly long history of contamination. Meanwhile, the benthic epifauna mapping in the worst impacted area of Taean indicated that the coastal organisms are fairly recovered after five years of the HSOS. However, it should be noted that residual oils are still found in some inner part of small bays and mud dominant regions in Taean area which would cause the potential toxic effects on coastal organisms. Finally, the current understandings and limitations of such effects from the HSOS are further discussed highlighting, i) long-term effects of residual oils, ii) identification of certain toxic chemicals in residual oils, iii) weathering characteristics of spilled oils, iv) possible effects from the unknown hydrocarbons in oils, and v) recovery of community level responses to the HSOS.