The Sanchi, a tanker carrying 136,000 tons, or about 1 million barrels, of oil, caught fire and sank in Chinese waters in mid-January, with the spill area affecting 332 sq km of sea surface by January 21st. According to media reports, “The oil tanker was carrying condensate oil, which differs considerably from the thick black oil slicks typically associated with a spill. Instead, the colourless oil is a liquid only under certain conditions and is partially soluble in water, making it much harder to separate and detect”.
On January 26th, Reuters produced a graphic showing the possible spread of oil/ affected water over the next 100 days. They suggest that South Korean officials believe that most of the oil will evaporate, presumably in line with research conducted elsewhere which suggests that condensate oil has a very short life once exposed to the environment (one study suggested a half-life of 3-7 days for one type of condensate).
If this does not happen for some reason, then, because of sea currents, the oil is predicted to move north toward Jeju Island; and then on northeast through the Korean Strait/ South Sea.
What might the impacts be?
In the worst case, at least one important seabird colony would be affected (Mara, southwest off Jeju Island); and oil is then predicted to spread to two areas that Birds Korea considers as candidates for Marine Important Bird and Biodiversity Areas – (1) the narrow strait between Busan and Teima Do/ Tsushima island (used by large numbers of birds during migration); and (2) the area off from the Guryongpo Peninsula close to Pohang in the southeast, used by very large concentrations of wintering and staging birds – large numbers of which likely will still to be present in April with smaller numbers into early May (i.e ~100 days from now).
Although there has been very limited survey effort of seabirds at sea in Korean waters, the research that has been done to date suggests that the following bird species (listed below with their global conservation status) would likely be the most affected in ROK waters IF this model is accurate, and the condensate does not evaporate as hoped:
a) Likely to be affected in large numbers (e.g. thousands to tens of thousands of individuals)
- Red-throated Loon Gavia stellata (LC)
- Pacific Loon Gavia pacifica (LC)
- Black-tailed Gull Larus crassirostris (LC)
- Vega Gull Larus vegae (LC)
- Ancient Murrelet Synthliboramphus antiquus (LC)
b) Likely to be affected in substantial numbers (e.g. 100s to thousands of individuals)
- Arctic Loon Gavia arctica (LC)
- Swinhoe’s Storm Petrel Oceanodroma monorhis (NT)
- Streaked Shearwater Calonectris leucomelas (NT)
- Great Cormorant Phalacrocorax carbo (LC)
- Red-necked Phalarope Phalaropus lobatus (LC)
- Common Gull Larus canus (LC)
- Common Tern Sterna hirundo (LC)
- Crested Murrelet Synthliboramphus wumizusume (VU)
c) Likely to be affected in small numbers (low 10s to 100s of individuals, still potentially significant at the national level):
- Yellow-billed Loon Gavia adamsii (NT)
- Great Crested Grebe Podiceps cristatus (LC)
- Black-necked Grebe Podiceps nigricollis (LC)
- * Pacific Reed Egret Egretta sacra (LC)
- Temminck’s Cormorant Phalacrocorax capillatus (LC)
- * Western Osprey Pandion haliaetus (LC)
- Black-legged Kittiwake Rissa tridactyla (VU)
- Black-headed Gull Chroicocephalus ridibindus (LC)
- Taimyr Gull Larus heuglini taimyrensis (LC)
- Aleutian Tern Onychoprion aleuticus (VU)
- Pomarine Jaeger Stercorarius pomarinus (LC)
- Long-billed Murrelet Brachyramphus perdix (NT)
*if oil reaches shoreline
Impacts on Jeju Island could also be substantial in terms of culture (e.g. the women divers), tourism, fisheries. National impacts will include fisheries; mariculture
During the last big oil spill(s) in 2007, there was a limited and belated response in the ROK. Most importantly, there were no properly equipped wildlife cleaning centres in place; and the only immediate large-scale response was the mobilisation of thousands of people volunteering to mop up spill on beaches. One problem with this spill is that if it indeed reaches Korean waters, it might still be mixed with water and will likely affect many areas which are hard to reach from large human population centres.