Joan Albaigés on the Importance of Response Protocols in Oil Spills
Special Topic of Oil Spills Interview, October 2010
The majority of your highly cited papers are about either the Prestige spill or the Aegean Sea spill. Why are these spills in particular so significant?
The northwest Spanish coast is exposed to heavy tankers' traffic and to very rough weather in several periods of the year, particularly during winter. Consequently, the risk of accidental oil spills is moderate. Moreover, the Galicia coastal ecosystem is one of the primary producers of mussels worldwide, so oiling of the marine rope systems used to grow the mussels, or just any loss of water quality, may have significant detrimental effects.
In this context, the Aegean Sea and Prestige oil spills have been the most important accidents that occurred in the area during the last 20 years and attracted an exceptionally high level of public attention and concern due to the large extension of the areas affected, and the perceived high ecological and socioeconomic impacts.
In December 1992, after several days of severe weather conditions, the tanker Aegean Sea ran aground off La Coruña harbor, on the Galician coast (northwest Spain). The tanker was transporting 79,000 tons of the relatively light Brent crude oil (North Sea) from Sulloe Voe to La Coruña refinery. The first rescue operations were unsuccessful and in a short time the ship broke in two and caught fire. For five days the tanker was leaking and burning oil.
"A detailed understanding of the fate of an oil spill is essential in order to foresee the extension of the environmental damage and to develop effective restoration strategies"
However, from the combined effects of severe weather and fire the amount of oil which affected the coastal area was only around 10% of the cargo. The winds and sea currents drove the spilled oil and the combustion products towards the northeast, rather far from the wreck point.
Ten years later (November 2002), another accident occurred, in this case involving the single hull tanker Prestige, carrying 77,000 tons of heavy fuel-oil. The tanker suffered a severe structural failure of the starboard cargo tanks 30 miles off the Galician coast and started to leak oil.
After six days of erratic towing along the coast, the tanker broke in two and sunk at the Galicia Bank (3,800 m depth, 150 miles offshore). The winds and sea currents drove the patches of about 60,000 tons of emulsified oil towards the shore, affecting more than 800 km of the northwest Spanish coast.
Apart from the current technical activities derived from the response systems, involving operational forecasting, risk and damage assessment, restoration measures, and environmental monitoring, these accidents deserved a major interest from the scientific point of view.
In the case of the Aegean Sea, the combination of a light crude oil with the combustion products provided a unique case for the study of the fate of different types of hydrocarbons in the marine environment. The Prestige spill was unique in the sense that heavy oil was dispersed at sea in a very large area, drifting for more than six months, and most of it leaking from a wreck at high water depth. The burial of oil at several meters on sandy beaches posed an unforeseen challenge to the clean-up operations (Environ. Sci. Technol., 43: 2470, 2009).
What do you hope we have learned from past spills to be able to apply to current/future spills?
A major lesson learned from past accidental spills is that besides the initial high emotional impact on the society and the immediate economic consequences, both by the impact on fishing activities and the cost of the remediation operations, the marine environment is able to recover in a rather short period of time if the response is produced according to well-established protocols. In this respect, the use of adequate clean-up operations is crucial.
In general, when the oil is removed, the levels of hydrocarbons in marine biota go to background in less than six to eight months and the environment is steadily re-populated with the damaged species in one to two years.
Nowadays, the methodologies for assessing the sources and fate of petroleum hydrocarbons in the marine environment are robust enough to support the response mechanisms and decision-making systems, enabling the adoption of best operational practices.
Joan Albaigés, Ph.D.
Department of Environmental Chemistry
CSIC
Barcelona, Spain
KEYWORDS: GEOCHEMICAL PROCESSES, OFF-SHORE OIL EXPLORATION, ENVIRONMENTAL IMPACT, TOURISM, SURVEILLANCE SYSTEM, GCMS FINGERPRINTING TECHNIQUES, IXTOC, METULA, AEGEAN SEA, PRESTIGE, MARINE POLLUTION MONITORING PROGRAMS, OIL SPILL FATE, RESTORATION STRATEGIES, DISPERSION, DISSOLUTION, COMPOSITION, CONCENTRATION, SOLUBLE FRACTION, AROMATIC HYDROCARBONS, BEACH OILING, CONTINENTAL SHELF, WILD BIVALVES, SEDIMENTS, TANKER TRAFFIC, ROUGH WEATHER, NORTHWEST SPANISH COAST, MUSSELS, CLEAN-UP OPERATIONS.