Summaries of major tanker spills from 1967 to the present day. More incidents will be added shortly.
- AMOCO CADIZ (France, 1978)
- ARGO MERCHANT (USA, 1976)
- BRAER (UK, 1993)
- CASTILLO DE BELLVER (South Africa, 1983)
- ERIKA (France,1999)
- EXXON VALDEZ (USA, 1989)
- METULA (Chile, 1974)
- PRESTIGE (Spain, 2002)
- SEA EMPRESS (UK, 1996)
- TANIO (France, 1980)
- TASMAN SPIRIT (Pakistan, 2003)
- TORREY CANYON (UK, 1967)
AMOCO CADIZ (France, 1978)
The tanker AMOCO CADIZ ran aground off the coast of Brittany on 16 March 1978 following a steering gear failure. Over a period of two weeks the entire cargo of 223,000 tonnes of light Iranian and Arabian crude oil and 4,000 tonnes of bunker fuel was released into heavy seas. Much of the oil quickly formed a viscous water-in-oil emulsion, increasing the volume of pollutant by up to five times. By the end of April oil and emulsion had contaminated 320km of the Brittany coastline, and had extended as far east as the Channel Islands.
Strong winds and heavy seas prevented an effective offshore recovery operation. All told, less than 3,000 tonnes of dispersants were used. Some chalk was also used as a sinking agent, but with the consequence of transferring part of the problem to the sea bed. The at-sea response did little to reduce shoreline oiling. A wide variety of shore types were affected, including sandy beaches, cobble and shingle shores, rocks, seawalls and jetties, mudflats and saltmarshes. Removal of bulk free oil trapped against the shore using skimmers proved difficult, largely due to problems with seaweed and debris mixed with the oil. Greater success was achieved with vacuum trucks and agricultural vacuum units, although much of the free oil was simply removed by hand by more than 7,000 personnel (mainly military). A considerable portion of the oil that did come ashore eventually became buried in sediments and entrapped in the low energy salt marshes and estuaries.
At the time, the AMOCO CADIZ incident resulted in the largest loss of marine life ever recorded after an oil spill. Two weeks after the accident, millions of dead molluscs, sea urchins and other benthic species washed ashore. Although echinoderm and small crustacean populations almost completely disappeared from some areas, populations of many species had recovered within a year. Diving birds constituted the majority of the nearly 20,000 dead birds that were recovered. Oyster cultivation in the estuaries ("Abers") was seriously affected and an estimated 9,000 tonnes were destroyed because of contamination and to safeguard market confidence. Other shell and fin fisheries as well as seaweed gathering were seriously affected in the short-term, as was tourism. Cleanup activities on rocky shores, such as pressure-washing, as well as trampling and sediment removal on salt marshes caused biological impacts. Whilst rocky shores recovered relatively quickly, the salt marshes took many years. Failure to remove oil from temporary oil collection pits on some soft sediment shorelines before inundation by the incoming tide also resulted in longer-term contamination. Numerous cleanup and impact lessons were learned from the AMOCO CADIZ incident, and it still remains one of the most comprehensively studied oil spills in history.
Selected Bibliography
Bellier, P. and Massart, G. (1979). The Amoco Cadiz oil spill cleanup operations - an overview of the organisation, control and evaluation of the cleanup techniques employed. Proceedings of the 1979 Oil Spill Conference, 141-146. API Publication No. 4308. American Petroleum Institute, Washington, DC, USA
NOAA (1978). The Amoco Cadiz oil spill: A preliminary scientific report. A National Oceanic and Atmospheric Administration and Environmental Protection Agency special report, Washington DC, USA
Spooner, M.F. (editor) (1978). The Amoco Cadiz oil spill. Special edition of Marine Pollution Bulletin 9 (7). Pergamon Press, Oxford and New York
Conan, G., d'Ozouville, L., and Marchand, M. (1978). Amoco Cadiz - preliminary observations of the oil spill impact on the marine environment. One day session, Amoco Cadiz, Brest, France, 7 June 1978. Le Centre National pour l'Exploitation des Oceans, Paris, France
Links
CEDRE - Case History
www.cedre.fr
ARGO MERCHANT (USA, 1976)
ARGO MERCHANT ran aground on Nantucket Shoals, off Massachusetts, USA, on 15 December 1976, and over the next month spilled her entire cargo (28,000 tonnes) of Venezuelan No 6 fuel oil and cutter stock. Storms broke up the tanker after grounding, and attempts to pump the oil into another vessel failed. In-situ burning was attempted on two occasions, but the slick failed to remain alight.
Winds during the spill period were offshore from Massachusetts, and as a result no oil from ARGO MERCHANT ever reached the shoreline and no coastal impact was reported. Hydrocarbon contamination of the bottom sediments was restricted to an area immediately around the wreck, and apparently was short-lived. The bulk of the spill formed large 'pancakes' and sheens on the surface; these were carried offshore over the continental shelf and into the prevailing North Atlantic circulation pattern. The cutter stock, which was mixed with the fuel oil to improve handling, entered the water column. Despite its relatively high potential toxicity, there was little evidence of impact on the marine fauna or phytoplankton. The accident occurred at the time when the fewest potential effects on pelagic organisms would be expected; a period of low productivity in the water column, with few fish eggs and larvae present. Oiled birds were seen near the wreck, and though total mortalities are difficult to evaluate, it was concluded that the spill probably had little effect on the coastal and marine bird populations off the New England coast. The outcome of the ARGO MERCHANT oil spill appears to have been fortunate in several respects: - the winds were almost continuously offshore, preventing the oil from coming on the beaches; the density of the oil was low enough so that it did not sink and contaminate the bottom, and the spill occurred in the winter when the biological activity, productivity, and fishing activities are relatively low.
Selected Bibliography
Winslow, R. (1978). Hard aground: The story of the Argo Merchant oil spill. W.W. Norton & Company Inc, New York, USA
Grose, P.L. & Mattson, J.S. (editors) (1977). The Argo Merchant oil spill: A preliminary scientific report. Govt Print. Off. [for] Department of Commerce, National Oceanic and Atmospheric Administration, Washington, DC, USA
Center for Ocean Management Studies (1978). In the wake of the Argo Merchant. Proceedings of a Symposium, 11-13 January 1978. University of Rhode Island, USA
BRAER (United Kingdom, 1993)
Following engine failure, BRAER ran aground in severe weather conditions on Garth's Ness, Shetland on 5 January 1993. Over a period of 12 days the entire cargo of 84,700 tonnes of Norwegian Gullfaks crude oil, plus up to 1,500 tonnes of heavy bunker oil, were lost as almost constant storm force winds and heavy seas broke the ship apart. Weather conditions prevented the use of mechanical recovery equipment at sea, although about 130 tonnes of chemical dispersant was applied from aircraft during periods when the wind abated slightly and some oil remained on the surface. Oiling of shorelines was minimal relative to the size of the spill and cleanup involved the collection of oily debris and seaweed by a small workforce.
The BRAER spill was very unusual in that a surface slick was not produced. A combination of the light nature of the oil and the exceptionally strong wind and wave energy naturally dispersed the oil throughout the water column. The oil droplets were adsorbed onto sediment particles which eventually sank to the sea bed. Sub-surface currents led to this oil being spread over a very wide area, although a significant portion eventually ended up in two deep, fine sediment 'sinks'.
A wide range of fish and shellfish over a fairly large area became contaminated with oil, resulting in the imposition of a Fisheries Exclusion Zone. Farmed salmon held in sea cages in the surface waters within this zone bore the brunt of the contamination since they could not escape the cloud of dispersed oil. Although this contamination was lost quickly once clean water conditions returned, millions of salmon that could not be marketed had to be destroyed. The Exclusion Zone was progressively lifted as fish and shellfish species were found by chemical analysis and taste testing to be free of contamination, although it was still in place over 6 years after the spill for mussels and Norway lobsters at some sites within the closure area.
The BRAER spill was unusual in that a significant amount of oil was blown on to land adjacent to the wreck site. The effects of this airborne oil were localised and had no more than a temporary impact on vegetation and livestock. Seabird casualties were also relatively low. Considering the size of the spill, the environmental impacts were surprisingly limited.
Selected Bibliography
Davies, J.M. & Topping, G. (editors) (1997). The impact of an oil spill in turbulent waters: The Braer. Proceedings of a symposium held at the Royal Society of Edinburgh, 7-8 September 1995. Stationery Office, Edinburgh, UK
ESGOSS (1994). The environmental impact of the wreck of the Braer. Scottish Office, Edinburgh, UK
Marine Pollution Control Unit (1993). The Braer Incident, Shetland Islands, January 1993. HMSO, London, UK
Links
CEDRE - Case History
www.cedre.fr
CASTILLO DE BELLVER (South Africa, 1983)
CASTILLO DE BELLVER, carrying 252,000 tonnes of light crude oil (Murban and Upper Zakum), caught fire about 70 miles north west of Cape Town, South Africa on 6 August 1983. The blazing ship drifted off shore and broke in two. The stern section - possibly with as much as 100,000 tonnes of oil remaining in its tanks - capsized and sank in deep water, 24 miles off the coast. The bow section was towed away from the coast and was eventually sunk with the use of controlled explosive charges. Approximately 50-60,000 tonnes are estimated to have spilled into the sea or burned. Although the oil initially drifted towards the coast, a wind shift subsequently took it offshore, where it entered the north-west flowing Benguela Current.
Although a considerable amount of oil entered the sea as a result of the CASTILLO DE BELLVER incident, there was little requirement for cleanup (there was some dispersant spraying) and environmental effects were minimal. The only visible damage was the oiling of some 1,500 gannets, most of which were collected from an island near the coast where they were gathering for the onset of the breeding season. A number of seals were observed surfacing in the vicinity of the dispersant spraying activities but were not thought to have suffered any adverse effects.
Also of initial concern was the 'black rain' of airborne oil droplets that fell during the first 24 hours of the incident on wheat growing and sheep grazing lands due east of the accident, although no long-term damage was recorded from these residues. The impact on both the rich fishing grounds and the fish stocks of the area was also considered to be negligible.
Selected Bibliography
Moldan, A.G.S. et al (1985). Some aspects of the Castillo de Bellver oil spill. Marine Pollution Bulletin 16 (3) 97-102
Wardley-Smith, J. (1983). The Castillo de Bellver. Oil and Petrochemical Pollution 4 (1) 291-293
ERIKA (France, 1999)
The Maltese tanker ERIKA, carrying some 31,000 tonnes of heavy fuel oil as cargo, broke in two in a severe storm in the Bay of Biscay on 11 December 1999, 60 miles from the coast of Brittany. About 20,000 tonnes of oil were spilled. The bow sank on 12 December and the stern on the following day.
The French Naval Command in Brest took charge of the response operations at sea in accordance with the French National Contingency Plan. Response vessels were mobilised on 14 December, but attempts at skimming ultimately met with little success owing to the poor weather and widespread fragmentation of the slick. In 15 days of operations 1,100 tonnes of oil/water mixture were collected, mainly during a 24-hour period of relatively calm weather and reduced swell. It has been estimated that less than 3% of the total spill volume was collected during the response operations at sea.
Owing to the influence of strong winds and currents, shoreline oiling did not occur as quickly as expected or in the locations originally forecast. After first moving south-east from the spill site toward La Rochelle, then turning north, the oil finally began stranding around the mouth of the River Loire on Christmas Day 1999. Intermittent oiling subsequently occurred over some 400km of shoreline between Finistère and Charente-Maritime. Due to the long time that the oil spent at sea, much of it formed a water-in-oil emulsion, which increased its volume and viscosity.
The degree of oiling of shores was very patchy through the affected area. The most heavily contaminated areas were located in Loire Atlantique, the northern Vendée and on offshore islands, notably Belle Ile. These areas required the mobilisation of considerable cleanup resources to carry out a programme of initial bulk oil removal, followed by prolonged and difficult secondary cleaning. Other areas received only very light oiling (eg parts of Finistère and Morbihan) where fine cleaning alone was needed.
During the cleanup operation, more than 250,000 tonnes of oily waste was collected from shorelines and temporarily stockpiled. Temporary reception facilities were established in car parks and stretches of land close to beaches, mainly by building earth or sand bunds or digging holes and lining them with plastic. Ultimately, the French oil company Total agreed to receive all the wastes at their Donges refinery, where adequate storage sites were available within and close to the refinery. Little attention was paid to segregation of wastes, however. The result was a mixture of oil, sand, debris, seaweed, protective clothing, damaged booms and other response equipment like scrapers, buckets and spades, which needed sorting before disposal could proceed.
Operations to pump out oil remaining in the sunken sections of ERIKA began once the weather improved in June 2000 and were successfully completed within three months. Some 10,000 tonnes of oil were recovered during the main pumping operations. Fine cleaning added a further 1,200 tonnes.
The main environmental impact of the spill was on sea birds. Almost 65,000 oiled birds were collected from beaches, of which almost 50,000 were dead. A major cleaning operation was mounted for the 15,000 oiled survivors and 2,000 were ultimately released.
The magnitude of the spill and the length of coastline affected resulted in a large number of compensation claims. There are important coastal fisheries, mariculture (oysters and mussels) and tourism resources throughout southern Brittany and the Vendée. Salt production areas were also affected by oil pollution.
Selected Bibliography
The ERIKA oil spill: environmental contamination and effects in the Bay of Biscay (2004). Special issue of Aquatic Living Resources, Volume 17, Number 3, July-September 2004. EDP Sciences
Le Guerroue, P., Poupon, E., Merlin, F.X., Cariou, G. (2003). Recovery of sunken and buried oil in coastal water during the Erika spill. Proceedings of the International Oil Spill Conference 2003, Vancouver, Canada, 6-11 April 2003 (CD ROM). American Petroleum Institute, Washington DC, USA
Ragot, R., Poncet, F., Laruelle, F., Tintilier, F. (2003). Results of a three year monitoring programme on the natural recovery of vegetation after the Erika oil spill: Lessons for adapting response techniques. Proceedings of the International Oil Spill Conference 2003, Vancouver, Canada, 6-11 April 2003 (CD ROM). American Petroleum Institute, Washington DC, USA
Laruelle, F., Kerambrun, L. (2001). Erika oil spill: some innovations in the French shoreline response and beach cleanup methods. Proceedings of the twenty-fourth Arctic and Marine Oilspill Program (AMOP) technical seminar (including 18th TSOCS and 3rd PHYTO), Edmonton, Canada, 12-14 June 2001, 671-678. Environment Canada, Ottawa, Canada
Couvreur, J.-F., Scherrer, P. (2001). Treatment of waste from the Erika spill. Proceedings of the International Oil Spill Conference 2001, Tampa, Florida, 26-29 March 2001 (CD ROM). American Petroleum Institute, Washington DC, USA
LeDrean-Quenec'hdu, S., Jacques, J-P., Lamy, A. (2001). The Erika oil spill: The bird rescue response. Proceedings of the International Oil Spill Conference 2001, Tampa, Florida, 26-29 March 2001 (CD ROM). American Petroleum Institute, Washington DC, USA
Peigne, G., Cabioc'h, F. (2001). Offshore operations following the Erika oil spill. Proceedings of the International Oil Spill Conference 2001, Tampa, Florida, 26-29 March 2001 (CD ROM). American Petroleum Institute, Washington DC, USA
Links
CEDRE - Case History
www.cedre.fr
International Oil Pollution Compensation Funds
www.iopcfund.org/erika.htm
EXXON VALDEZ (United States, 1989)
EXXON VALDEZ grounded on Bligh Reef in Prince William Sound, Alaska, on 24 March 1989. About 37,000 tonnes of Alaska North Slope crude escaped into the Sound and spread widely. There was some limited dispersant spraying and an experimental in-situ burn trial during the early stages of the spill, but at-sea response concentrated on containment and recovery. Despite the utilisation of a massive number of vessels, booms and skimmers, less than 10% of the original spill volume was recovered from the sea surface. The oil subsequently affected a variety of shores, mainly rock and cobble, to varying degrees over an estimated 1,800km in Prince William Sound and along Alaska's south coast as far west as Kodiak Island.
This spill attracted an enormous amount of media attention because it was the largest spill to date in US waters (although well down the scale in world terms). Moreover, it happened in a splendidly scenic wilderness area with important fisheries and attractive wildlife such as sea otters and bald eagles. Consequently the response was the most expensive in oil spill history, with over 10,000 workers being employed at the height of the cleanup operations, many of them in shoreline cleanup, often in remote areas. The clean-up cost for the first year alone was over US$2 billion.
Shoreline cleanup techniques included high pressure, hot water washing, which was carried out on a scale never attempted previously or subsequently. This caused substantial impact in intertidal communities and may have delayed their recovery in some areas, although recovery on over 70% of oiled shorelines was progressing well one year after the spill. There were also some relatively large scale bioremediation trials that gave mixed results. About 1,000 sea otters are known to have died, and over 35,000 dead birds were retrieved. There were particular efforts to protect fisheries, for example with booming of salmon hatcheries. Oil residues remain trapped in intertidal sediments at a few locations and scientists dispute the evidence of long-term damage to wildlife and fish populations. Indeed, assessment of damage and recovery has been controversial because of the segregation of scientists into different camps, as a result of US litigation practices.
Selected Bibliography
Rice, S.D., Spies, R.B., Wolfe, D.A. and Wright, B.A. (editors) (1996). Proceedings of the Exxon Valdez oil spill symposium. American Fisheries Society, Bethesda, Maryland, USA
Wells, P.G., Butler, J.N. and Hughes, J.S. (editors) (1995). Exxon Valdez oil spill - fate and effects in Alaskan waters. ASTM (STP 1219), Philadelphia, USA
Galt, J.A., Lehr, W.J. and Payton, D.L. (1991). Fate and transport of the Exxon Valdez oil spill. Environmental Science & Technology 25 (2) 202-209
Alaska Sea Grant College Program (1995). Prevention, response and oversight five years after the Exxon Valdez oil spill. Proceedings of an international conference, 23-25 March 1994, Anchorage, Alaska. Report no. 95-02. University of Alaska, Fairbanks, USA
Loughlin, T.R. (editor) (1994). Marine mammals and the Exxon Valdez. Academic Press Inc, San Diego, USA
Links
CEDRE - Case History
www.cedre.fr
Exxon Valdez Oil Spill Trustee Council
www.evostc.state.ak.us/
Valdez Science - An Environmental Update
Results of key scientific studies of Prince William Sound and the Gulf of Alaska following the Exxon Valdez oil spill. Supported by ExxonMobil Inc.
http://www.valdezscience.com/index.cfm
METULA (Chile, 1974)
METULA grounded in the eastern Strait of Magellan, Chile, on 9 August 1974. About 47,000 tonnes of light Arabian crude oil and 3,000 to 4,000 tonnes of heavy fuel oil are estimated to be have been lost. Large volumes of water-in-oil emulsion were produced in the rough sea conditions and much of this landed on shores of northern Tierra del Fuego. Most of the shores affected were of mixed sand and gravel, but two small estuaries including saltmarshes were also oiled. About 4,000 birds are known to have been killed, including cormorants and penguins.
No cleanup was done because of the remoteness of the area and consequently this remains a distinctive spill site mainly because hard asphalt pavements formed on many shorelines. The long-term fate and effects of heavy oiling have been extensively investigated. One very sheltered marsh received thick deposits of mousse and, 20 years after the spill, these deposits were still visible on the marsh surface, with the mousse quite fresh in appearance beneath a weathered surface skin. Little plant re-colonisation has occurred in the areas with thicker deposits of 4 or more cm, though it is proceeding in more lightly oiled areas. On sand and gravel shores, an asphalt pavement remained in a relatively sheltered area in 1998, but oil deposits had mainly broken up and disappeared from more exposed shores. These remain amongst the longest-term contaminants recorded for an oil spill, even though they have not resulted in significant impacts on fisheries or the biology of coastal waters.
Selected Bibliography
Guzman, L. and Campodonico, I. (1981). Studies after the Metula oil spill in the Straits of Magellan, Chile. In Proceedings of the Petromar '80 Conference, Monaco, 363-376. Graham and Trotman Ltd., London, UK
Owens, E. H., Robson, W. and Humphrey, B. (1987). Observations from a site visit to the Metula spill 12 years after. Spill Technology Newsletter 12, 83-96
PRESTIGE (Spain, 2002)
During the afternoon of Wednesday 13 November 2002, the tanker PRESTIGE (81,564 DWT), carrying a cargo of 77,000 tonnes of heavy fuel oil, suffered hull damage in heavy seas off northern Spain. She developed a severe list and drifted towards the coast, and was eventually taken in tow by salvage tugs. The casualty was reportedly denied access to a sheltered, safe haven in either Spain or Portugal and so had to be towed out into the Atlantic. Although attempts were made by salvors to minimise the stresses on the vessel, she broke in two early on 19 November some 170 miles west of Vigo, and the two sections sank some hours later in water two miles deep. In all, it is estimated that some 63,000 tonnes were lost from the PRESTIGE.
Owing to the highly persistent nature of PRESTIGE's cargo, the released oil drifted for extended periods with winds and currents, travelling great distances. Oil first came ashore in Galicia, where the predominantly rocky coastline was heavily contaminated. Remobilisation of stranded oil and fresh strandings of increasingly fragmented weathered oil continued over the ensuing weeks, gradually moving the oil into the Bay of Biscay and affecting the north coast of Spain and the Atlantic coast of France, as far north as Brittany. Some light and intermittent contamination was also experienced on the French and English coasts of the English Channel. Although oil entered Portuguese waters, there was no contamination of the coastline.
A major offshore cleanup operation was carried out using vessels from Spain and nine other European countries. The response, which was probably the largest international effort of its kind ever mounted, was hampered by severe weather and by the inability of those vessels that lacked cargo heating capability to discharge recovered oil. Over a thousand fishing vessels also participated in the cleanup in sheltered coastal waters and during favourable weather. As some of the oil moved into French waters, control of a reduced at-sea recovery operation passed to the French authorities.
The open-sea recovery operation off Spain reportedly removed almost 50,000 tonnes of oil-water mixture. However this, and the extensive booming of estuaries and sensitive areas by the deployment of over 20km of boom, failed to prevent extensive coastal contamination. Altogether approximately 1,900 km of shoreline were affected. The shorelines of Spain were largely cleaned manually by a workforce of over 5,000 military and local government personnel, contactors and volunteers. The process was slow, especially in rocky areas where access was difficult. A further problem was re-oiling of previously cleaned areas by re-mobilised oil. On the French Atlantic coast the beach contamination took the form of numerous tar balls which were relatively easy to remove. In total, some 141,000 tonnes of oily waste was collected in Spain and 18,300 tonnes in France.
Fisheries exclusion zones were put in place in Galicia shortly after the incident, banning virtually all fishing along about 90% of the coastline. All bans had been lifted by October 2003. The impact on fisheries in France was less extensive. In both countries, an impact on tourism was reported for 2003.
The Spanish authorities decided to remove the oil remaining in the wreck. The work commenced in May 2004 and was finalised in September 2004 at an estimated cost of some €100 million.
Selected Bibliography
Albaiges, J., Vilas, F., Morales-Nin, B. (2006). The Prestige: A scientific response. Marine Pollution Bulletin, Volume 53, Nos 5-7, 2006
Guillen, A.V. (2004). Prestige and the law: regulations and compensation. Proceedings of the 17th Annual Conference Oil Pollution 2004. Claims Handling and Cleanup Response, London, 15-16 March 2004. Lloyd's List Events, London, UK
Lorenzo, F.A. (2004). Clean-up, including some innovative solutions. Proceedings of the 17th Annual Conference Oil Pollution 2004. Claims Handling and Clean-up Response, London, 15-16 March 2004. Lloyd's List Events, London, UK
Rodriquez, X.N. (2004). Effects of the oil spill from the Prestige on the environment and its subsequent regeneration. Proceedings of the 17th Annual Conference Oil Pollution 2004. Claims Handling and Clean-up Response, London, 15-16 March 2004. Lloyd's List Events, London, UK
Links
CEDRE - Case History
www.cedre.fr
International Oil Pollution Compensation Funds
www.iopcfund.org/prestige.htm
International Maritime Organization
www.imo.org (accessed through "Information Resources on Current Topics")
SEA EMPRESS (United Kingdom, 1996)
On the evening of 15 February 1996, SEA EMPRESS, carrying 130,000 tonnes of Forties Blend North Sea crude oil, ran aground in the entrance to Milford Haven, South West Wales. Although the tanker was refloated within a couple of hours, it sustained serious damage to its starboard and centre tanks, resulting in a massive release of oil. Attempts to bring the vessel under control and to undertake a ship-to-ship transfer operation were thwarted by severe weather and the tanker grounded and refloated several more times over a period of five days. In all, some 72,000 tonnes of crude oil and 370 tonnes of heavy fuel oil were released into the sea between the initial grounding and the final refloating operation.
The SEA EMPRESS cleanup operations were wide-ranging and effective. At sea these included dispersant spraying, mechanical recovery and the use of the protective booms. This, coupled with a high rate of evaporation and natural dispersion, greatly reduced the quantity of oil reaching inshore waters. Some 200km of coastline - much of it in a National Park - was contaminated and a major shoreline cleanup effort had to be mounted, involving mechanical recovery, trenching, beach washing, and the use of dispersants and sorbents. The main recreational beaches were cleaned by the Easter holidays, some two months after the spill, although other areas required longer treatment throughout the summer. A temporary ban was imposed on commercial and recreational fishing in the region and there was concern that tourism, important to the local economy, would be badly affected by the heavily oiled beaches. Several thousand oiled birds washed ashore, leading to a major cleaning and rehabilitation operation.
The UK government appointed an independent committee, the Sea Empress Environmental Evaluation Committee (SEEEC), to assess the damage caused by the spill. It found that although some wildlife populations were damaged (some severely) and a few would take years to recover, the great majority proved resilient and after two years had regained their former abundance. It appears that although a very large amount of oil was spilled in a particularly sensitive area, the impact was far less severe than many people had expected. This was due to a combination of factors - in particular, the time of year, the type of oil, weather conditions at the time of the spill, the cleanup response and the natural resilience and recovery potential of many marine species.
Selected Bibliography
Moore, J. (2006). State of the marine environment in SW Wales, 10 years after the Sea Empress oil spill. Countryside Council for Wales, UK
Sime, H. & Edwards, R. (editors) (1998). The Sea Empress oil spill. Proceedings of a conference held in Cardiff 11-13 February 1998. CIWEM, Chartered Institution of Water and Environmental Management, UK
Sea Empress Environmental Evaluation Committee, SEEEC (1998). The environmental impact of the Sea Empress. Stationery Office, London, UK
Marine Pollution Control Unit, MPCU (1996). The Sea Empress incident. A report by the Marine Pollution Control Unit, December 1996. The Coastguard Agency, Southampton, UK
Edwards, R. & White, I. (1999). The Sea Empress Oil Spill: Environmental Impact and Recovery (1999). Proceedings of the International Oil Spill Conference 1999, 7-12 March 1999, Seattle, USA, 97-102, American Petroleum Institute, Washington DC, USA
Links
CEDRE - Case History
www.cedre.fr
The Environmental Impact of the Sea Empress Oil Spill
Text of Sea Empress Environmental Evaluation Committee (SEEEC) summary report
http://www.archive.official-documents.co.uk/document/seeec/impact/seaemp.htm
The Sea Empress Incident: Summary of Report
Summary of the Marine Pollution Control Unit's report into the Sea Empress clean-up operation
http://www.dft.gov.uk/pgr/shippingports/shipping/elc/theseaempressincidentsummary5010
The Sea Empress Oil Spill
University of Wales, School of Biological Sciences
http://www.swan.ac.uk/empress/overview.htm
TANIO (France, 1980)
On 7 March 1980 TANIO, carrying 26 000 tonnes of No. 6 fuel oil, broke in two during violent weather conditions off the coast of Brittany, France. As a result approximately 13,500 tonnes of cargo oil was spilled. The stern section, with about 7,500 tonnes of cargo oil aboard, remained afloat and was towed to Le Havre; the bow section, carrying 5,000 tonnes of cargo oil, sank to a depth of 90 metres. Strong northwest winds at the time of the incident moved the oil towards the Breton coast (which had already received major oil impacts from the TORREY CANYON spill in 1967 and the AMOCO CADIZ in 1978). Due to the high viscosity of the oil and severe weather conditions, neither chemical dispersal nor containment and recovery techniques at sea were possible. The spilled oil began to be washed ashore on 9 March, and eventually contaminated about 200km of coastline to varying degrees. Many of the worst affected areas could not be boomed effectively because of the nature of the coastline, the extremely large tidal range (9m) and the severity of the weather at the time of the accident.
As tourism is of major importance in Brittany, the main emphasis of the cleanup operation was to return amenity areas to a usable condition as quickly as possible. In severely contaminated areas, bulk oil was removed by the use of tractor-drawn vacuum trucks, but this technique could not be used on cold, cloudy days when the oil became too viscous. Owing to concern that a forthcoming high tide would extend the shoreline contamination, it was decided that a more rapid removal of the bulk oil was required. Heavy earth-moving equipment (bulldozers and front-end loaders) was therefore used despite the well-known detrimental effects of driving heavy equipment over severely oiled beaches. While much oil (and a considerable amount of beach material) was removed within a short time, the underlying sediments at a number of sites were heavily contaminated and required extensive restoration work at a later stage. Where access was difficult or where the deposits of oil were thin or well spread out, men with shovels were employed to pick up the oil and to put it into sacks or tractor-drawn trailers. Oil collected during the cleanup operation was taken to a tanker deballasting station for treatment. The removal of bulk oil was followed by the cleaning of the rocks in the tourist areas, using hot water washing machines and high pressure cold water jets. Released oil was collected using granular mineral sorbents and dispersants were used in cases of severely contaminated rocks. By the time the cleanup operation was completed at the beginning of July most of the beaches and accessible rocks had been restored to something approaching their pre-spill state.
The TANIO spill presented considerable cleanup problems to which there was no easy solution, but the low toxicity of the oil meant that the environmental effects were limited. Approximately 1,700 dead birds, primarily guillemots and other auks, were recovered during the incident, and there were some localised effects - such as contaminated oyster beds and disrupted seaweed harvests - caused by the smothering of intertidal life and by the extensive cleanup operations at the worst affected areas.
Selected Bibliography
Ganten, R.H. (1985). The Tanio spill: A case history illustrating the work of the International Oil Pollution Compensation Fund. Proceedings of the 1985 Oil Spill Conference, 135-139. API Publication No.4385. American Petroleum Institute, Washington DC, USA
Brac, C. (1981). Operation Tanio. La Nouvelle Revue Maritime. July, 363, 10-25.
Links
CEDRE - Case History
www.cedre.fr
TASMAN SPIRIT (Pakistan, 2003)
The Maltese tanker TASMAN SPIRIT (87,584 DWT) grounded at the entrance to Karachi Port, Pakistan in the early hours of Sunday 27 July 2003. The vessel was carrying 67,800 tonnes of Iranian Light crude oil destined for the national refinery in Karachi. There were also 440 tonnes of heavy fuel oil in aft bunker tanks. The condition of the grounded tanker deteriorated as she was subjected to continuous stress from the heavy swell of the prevailing south-west monsoon and the vessel subsequently broke in two. In total, it is estimated that some 30,000 tonnes of oil was spilled from the TASMAN SPIRIT.
In the course of inspections on board the TASMAN SPIRIT it became apparent that most of the cargo tanks had been ruptured, whilst the bunker tanks remained intact. The owners appointed salvors and also hired a succession of small tankers and barges for the purpose of shuttling and storing oil lightered from the casualty. During the next few weeks roughly half of the crude oil cargo and most of the bunker fuel was successfully transferred from the casualty.
On 11 August the tanker began to show signs of breaking up and eventually broke in two overnight on 13/14 August, spilling several thousand tonnes of crude oil. Much of the spilled oil quickly stranded on Clifton Beach, the main tourist beach in Karachi, but significant quantities remained afloat both inside and outside Karachi port. Dispersants were applied offshore from a Hercules C-130 aircraft equipped with an aerial dispersant spraying system (ADDS Pack) in response to two distinct pollution events involving the progressive break-up of the tanker. Approval for large scale dispersant use was given by the Karachi Port Trust (KPT) and the Pakistan Environment Protection Agency.
Oil entering the port of Karachi was confined by deploying booms at suitable collection sites, and in total some 140 tonnes of oil were recovered by skimmers. KPT also deployed vessels to apply dispersant on oil drifting through the port entrance.
The severe pollution of Clifton Beach created very strong oil vapours causing considerable discomfort to local residents and clean-up personnel. Local hospitals reported many cases of headaches, nausea and dizziness and seventeen schools in the vicinity were closed for about a week. The beach was cleaned by a combination of manual and mechanical means, but work was hampered by a lack of suitable disposal sites for collected oily waste. Agreement was eventually reached for disposal at one of the municipal waste sites serving Karachi City. Clifton Beach was re-opened to the public in the middle of October.
Given the low persistence of Iranian Light crude oil and the high mixing energy in the many damaged cargo tanks generated by the incessant heavy swell, it is likely that most of the spilled oil dispersed naturally. Field surveys conducted showed little or no impact on mangroves, salt pans and other sensitive resources in the vicinity. The geographical extent of shoreline oiling was limited to a ten-mile radius around the grounded tanker.
Whilst there were few reports of repercussions of the oil on fisheries, a three-month fishing ban was imposed by the Marine Fisheries Department along the coastline directly affected by oil, extending five nautical miles offshore.
Links
CEDRE - Case History
www.cedre.fr
TORREY CANYON (United Kingdom, 1967)
TORREY CANYON ran aground on Pollard Rock on the Seven Stones Reef, near Lands End, Cornwall on 18 March 1967. Thousands of tonnes of oil were soon spilling from the stricken vessel's ruptured tanks and during the next 12 days the entire cargo of approximately 119,000 tonnes of Kuwait crude oil was lost.
A wide variety of methods to mitigate the spill were tried. Burning the slick proved unsuccessful, and eventually the British Government gave orders for TORREY CANYON to be destroyed by aerial bombardment in the hope that all the oil still remaining on board would be burnt off. This operation was partially successful, but did not prevent escaping oil from polluting many parts of the south west of England, causing the deaths of thousands of seabirds and threatening the livelihoods of many local people in the forthcoming summer tourist season. Later the drifting oil polluted beaches and harbours in the Channel Islands and Brittany.
A distinguishing feature of the TORREY CANYON response operation was the excessive and indiscriminate use of early dispersants and solvent based cleaning agents, which caused considerable environmental damage. The dispersants were generally successful at their task of reducing the amount of oil arriving ashore and subsequently expediting onshore cleanup operations, but they were considerably more toxic than those used today and were applied in far greater concentrations, often being poured undiluted on slicks and beaches. Many of the detrimental impacts of the spill were later related to the high volume, high concentration and high toxicity of the dispersant and detergents used.
The TORREY CANYON was the first major tanker disaster to be brought to the notice of the general public due to enormous media coverage, and drew universal attention to the dangers of dispersants. The spill triggered the international Conventions, which form the basis for compensation for damage caused by tanker spills, and interim voluntary agreements to bridge the gap before the Conventions entered into force and became widely accepted.
Selected Bibliography
Zuckerman, S. (1967). The Torrey Canyon. Report of the Committee of Scientists on the Scientific and Technological Aspects of the Torrey Canyon Disaster. Departments of State and Official Bodies. Cabinet Office, London, UK
Petrow, R. (1968). The black tide: in the wake of Torrey Canyon. Hodder & Stoughton, London, UK
Southward, E.C.& Southward, A.J. (1978). Recolonization of rocky shores in Cornwall after the use of toxic dispersants to clean up the Torrey Canyon spill. Journal of the Fisheries Research Board of Canada 35 (5) 682-706
Links
CEDRE - Case History www.cedre.fr