The largest oil spill in the Mediterranean: the MT Haven shipwreck

L’April 11, 1991 the oil tanker MT Haven, anchored off the port of Genoa, exploded causing 5 victims among the crew and the largest oil spill in the Mediterranean. The resulting fire, which lasted well 70 hours, burned most of the crude oil released, however leading to the release into the water and on the seabed of a quantity between 10 and 50,000 tons: the containment and recovery of the oil occupied the rescue efforts for years to come. The ship sank on 14 April off the coast of Arenzano, in the Gulf of Genoa: her wreck – the largest visitable in the Mediterranean – is located at 85 meters deep. The accident occurred a few hours after the Moby Prince disaster, in which 140 people lost their lives.

The MT Haven explosion: what happened and the causes

The tanker MT Haven belonged to VLCC category (Very Large Crude Carrier) ships of impressive size. Survived in 1987 to a missile attackduring the conflict between Iran and Iraqit had been repaired in Singapore to quickly resume service. At the time of docking on the platform off the coast of Genoa, it carried approx 230 thousand tons of Iranian oil.

After an initial transfer of 80 thousand tons, the ship detached from the platform to operate the movement between the different tanks of the remaining load (150,000 tons). During these operations, an initial fire and subsequent explosions they developed on the tanker, probably for the pump malfunction.

Part of the crew managed to save themselves, despite the fire: 18 people in particular they owe their lives to first aid, carried out by Commander Cerutti’s “pilotine”, alerted by the commander of the Haven following the first fires.

During the first hours of intervention, efforts were concentrated in oil containment released, thanks to 9 km of floating barriers, It is in the towing the shipstill on fire, towards the nearby stretch of coast.

These choices were decisive for reduce the effect of currents and the spilling of crude oil; during towing the ship, heavily damaged by the explosions, broke in two with the bow That sank offshore, at 490 m depth.

The fire lasted 70 hoursending only the April 14 with the sinking of the remaining wreck, at about 75 m depth: fortunately i you smoke they were pushed away from the coast thanks to the favorable weather conditions. Even that of do not extinguish at all the fire it was a decision made for reduce to a minimum the amount of oil released into watereven if at the price of heavy air pollution.

Cleaning operations and judicial events

Following combustion, the bituminous residue of oil sank to the seabedin estimated quantities between 10 and 50,000 tons: other 2000 tons they were recovered in water thanks to containment and special means for recovery, and between one thousand and 1500 tons (1% of the load at the time of explosion) they ended up on the coasts of Arenzano and surrounding areas.

In the days following the emergency phase, efforts were concentrated on recovery of the heaviest remaining fraction in the main part of the wreck (about 3000 tons), as well as on layer, 10 cm thick, of bitumen which accumulated on the seabed in a area of ​​120,000 square km. A fleet of ships, mechanized vehicles and operators cleaned up i approximately 100 km of coastline involved in the following months.

In the search for the cause of the disaster, he state of maintenance and repairs carried out on a budget on the ship, following the 1987 missile accident, they came under the scrutiny of investigators.

After years of accusations in different degrees of judgment of the Genoese and Italian courts, however, the entire affair resulted in a stalemate with the acquittal of the shipowners, the Stelios family.

They were paid anyway compensation For 95 billion lire in Italy and another 23 million francs in France, by the IOPC fund (International Oil Pollution Compensation), following agreements taken from 1992 with the government of the time, led by Prime Minister Andreotti. The figure, certainly important, was however far from the 1200 billion estimated by the ENI-IRI committee for a complete cleanup.

The consequences on the environment

The environmental monitoring of the affected area was activated just a few weeks after the accident: i first studies they concentrated on smarine species of the seabedlike the musselsmore commonly called mussels.

These molluscs accumulate organic substances present in the water: for this reason they were used as indicator of concentrations of petroleum derivatives in the area.

In addition to molluscs, also i bottom fish and sort of marine plants as the Posidonia Oceanica have been studied: fauna and flora too 15 miles from the wreck were affected by the spill, reporting PAH concentrations (Polycyclic Aromatic Hydrocarbons) higher than historical values. Studies on trawling fishing in the marine areas, especially in the area in front of Arenzano, they showed a 43% reduction in the catch compared to the years preceding the accident.

In 1999, the IOPC fund allocated 16.4 million euros for further studies and recovery interventions of the oil fractions remaining in the Haven wreck: the reclamation of the area was declared completed by the Civil Protection in 2008, however recognizing the technical infeasibility of a complete cleaning of the deepest seabed. To date, the only monitoring is the generic one of water quality carried out by Arpa Liguria, which indicates a level of pollutants in line with the rest of the Ligurian coast.

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