The Amoco Cadiz Oil Spill Disaster

The coast of Brittany near the Portsall Rocks, or Ploudalmézeau, where the oil spill occurred.

The Amoco Cadiz Oil Spill Disaster occurred when an oil tanker, named Amoco Cadiz, split into three and sank into the sea. The tanker had a lot of oil on board, which was all spilled, resulting to the largest ever oil spill in the sea in history. The accident occurred on March 16, 1978, while the ship was traveling from the coast of Brittany in France. Amoco Cadiz was owned by a Liberian company but managed and registered to an American shipping company.

Causes And Events Leading To The Accident

The ship had left Brittany and was headed to Lyme Bay in the Great Britain. The harsh weather at the sea contributed to the engines becoming faulty, which is considered the major reason behind the sinking of the tanker. When it was slammed by a heavy wave at 9.46 am, the tanker was north of Ushant and 16 nautical miles west of Portsall. It turned to avoid an oncoming ship. At this point, the ship developed a mechanical problem due to the loss of hydraulic fluid. The captain decided to shut down the engine and try and repair it but it was all in vain because of the strong wind that was blowing from the northwest. The wind helped drive the ship towards the shores.

Amoco Cadiz had drifted approximately six nautical miles towards the shore before the tugboat pacific managed to successfully attach a hawser to it at around 2 pm. For two hours, the tugboat tried to rectify Amoco’s drift in vain. The captain successfully managed to attach a new towline to Amoco Cadiz at around 8.55 pm. However, it hit a rock a moment later and began to leak. At around 9.30 pm, another rock made a hole at the base of the tanker, allowing water to flow into the engine room. The hull was ripped open leading to the oil spill. Luckily, no crew life was lost in the accident.

The crew on board was rescued by the French Naval Aviation at around 12 am. The captain and one other crew member remained on the ship up to the next day at 5.00 am. Within no time the engine room was flooded and this made the ship to start sinking. On March 17, the ship split into two, spilling all the crude and fuel oil into the sea. Eleven days later, stormy weather and fierce waves made it split further making three pieces.

The Oil Spill

Amoco Cadiz carried about 220,000 tons of light crude oil that had been obtained from Ras Tanura, Saudi Arabia and Kharg Island in Iran. All the crude oil that belonged to Shell and 4000 tons of fuel oil that was being ferried by the ship was all spilled due to the harsh weather conditions at the sea which led to the breaking of the ship. The northwesterly winds contributed a great deal in the quick spreading of the oil on the sea surface. The winds spread oil through the 72 km of the French shoreline. In the following month, the westerly winds furthered the spreading of the oil eastwards of the coast. Just a week after the accident, the oil had spread all the way to Cote’s d’Armor.

The oil penetrated up to depths of about 20 inches in the sands of affected beaches. During the rough weather, consistent transfer of sand resulted to the sub-surface oil being divided into two or three layers. Porspoder Harbor to the harbors in Brehat Island was covered with the oil. Pink Granite Rock beaches of Tregastel, Perros Guirec and the tourist beach of Plougasnou were some of the areas that were severely affected by the spill. The oils along the exposed rocky shores persisted for just a few weeks after the accident, thanks to the moderately high wave actions. However, in the areas that did not experience constant wave actions, the oils persisted for years in form of asphalt crust. Generally, a month after the oil spillage, the total distance of oil spread was approximately 320 km and a total of 76 beaches were affected.

The Clean-Up Process

Clean-up activities were carried out on the rocky shores to try and reduce the already heavy effects of the oil. The cleanup activity included pressure washing on the rocky shores. The oil on the rocky shores was eliminated quite quickly compared to salt marshes which took many years to eliminate. An organization of around 10,000 people was formed to carry out the cleaning process possible. The purpose of the organization was to clean-up selected areas, pumping out oil in places that oil had accumulated, and clean-up of beaches, shores, and harbors. The affected gravel and sand in some of the affected beaches were also cleared. Oil debris was also collected and disposed off safely. Not more than 20,000 tons of oil was retrieved after the separation of the emulsion of oil and water.

Effects Of The Amoco Cadiz Oil Spill Disaster

Being the largest oil spillage in the sea, Amoco oil spill disaster has had adverse effects, especially on the marine life. The oil spillage led to the largest ever loss of marine life in the first two months of its occurrence. Just two weeks after the spillage, millions of sea urchins, mollusks and other small organisms living in the bottom of the sea were killed. Approximately 9000 tons of oysters were also killed.

Birds of the sea were also largely affected, especially in their flight ability. The oil clung on the feathers of the wings of the birds making it difficult for the birds to fly in search of food and other necessities for survival hence leading to the death of many of them.

The live fish that were caught had a lot of disorders on their skin surfaces. These disorders included ulcerations and tumors. The fish caught in the area tasted like petroleum, due to their intake of affected organisms and water. Internally, the fish were also contaminated with the oil and the fish being consumed by human beings would have led to adverse effects.

Echinoderm and small organisms that belonged to the group of crustacean were almost eliminated from the sea. Luckily, they multiplied quickly and their population was restored within a year.

The oil eroded the affected beaches. In fact, erosion is still evident in some of the affected beaches. The erosion is still evident especially in areas were no attempts of cleaning-up were done.


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