Over 2,000 sq km oil slick reaches Oman coastline: Why the environmental damage could be severe

Oil spill specialist John Amos, who reviewed satellite images obtained by Reuters, estimated that the slick covered more than 2,000 square kilometres. Oman’s Environment Authority said the pollution could affect up to 40 kilometres of coastline near Ras Madrakah, reported Al Jazeera. It also warned that the southern coast of Masirah Island could face contamination over the next few hours.

The scale of the spill, the amount of oil believed to remain on the tanker and the location of the accident have created several risks for Oman’s marine environment. The affected waters include the Hallaniyat Archipelago, an area with important marine habitats and a protected marine reserve.

The Caroline Bezengi ran aground off Oman after suffering damage earlier in its journey. The tanker had reported a suspected explosion near Yemen on June 8. It later ran aground about 22 nautical miles, or 41 kilometres, from the Omani coastal town of Sharbithat. The vessel ran aground on June 30, reported Reuters.

The tanker had sailed from Russia towards India and carried an estimated 800,000 barrels of sanctioned Russian crude, reported Reuters. The vessel is believed to be part of Russia’s so-called shadow fleet, a network of older ships used to transport Russian oil while helping traders avoid Western sanctions.

The tanker last sailed under a Cameroonian flag. Open-source database OpenSanctions lists Rentoor Shipmanagement as the owner and Villar Shipmanagement as the operator, reported Al Jazeera. Both companies are based in China.

The vessel’s condition has made the situation more difficult. The ship is around 25 years old and lacks normal insurance coverage, reported Reuters. 

The environmental danger also comes from the location of the spill. The slick has concentrated around the Hallaniyat Archipelago, where Oman established a marine reserve in 2025, reported Al Jazeera. The area supports a wide range of marine life, including rare sea turtles. The region provides habitat for Arabian Sea humpback whales and Socotra cormorants, reported Reuters.

Oil can cause damage long after the visible slick disappears. Crude can coat beaches, rocks and marine vegetation. It can also affect birds and marine animals when they come into contact with the oil or ingest contaminated food.

Coral reefs, seagrass areas and other coastal habitats can face particular risks. Oil can block sunlight from reaching plants and can coat surfaces that marine organisms need for survival. Animals that depend on these habitats can then face a wider loss of food and shelter.

The impact can also move through the food chain. Small marine organisms can come into contact with oil. Fish and other animals can consume contaminated organisms. Larger species can then face exposure as they feed.

The spill could also hurt coastal communities that depend on fishing and tourism. Omani authorities have warned that more coastline could become contaminated as the slick moves with winds and sea currents.

Oman’s Environment Authority said some beaches in the Ras Madrakah area had already suffered oil pollution. The authority also warned that a coastal stretch of up to 40 kilometres could be affected, reported Al Jazeera.

Masirah Island faces another risk. The island sits about 15 kilometres from Oman’s coast, and the authority said oil could reach its southern beaches. It estimated that a 10-20 kilometre stretch of coastline could face contamination.

The arrival of the oil on land marks an important change in the crisis. A spill in open water can spread across a large area, but coastal contamination can cause more direct damage to beaches, wildlife habitats and human activities.

Why could the damage become severe?

The first concern is the amount of oil involved. Experts believe the tanker carried hundreds of thousands of barrels of crude, reported Al Jazeera. If the vessel breaks apart and releases much of its remaining cargo, the environmental impact could increase dramatically.

The tanker could release an estimated 40 million to 50 million gallons of crude if it breaks apart, reported Reuters. That would put the potential scale of the disaster in the range of some of the major oil spills of recent decades.

Christopher D’Elia, an oil-spill specialist and professor emeritus at Louisiana State University, told Al Jazeera that 800,000 barrels would amount to a “fairly large spill”. “This spill raises a lot of issues,” D’Elia told Al Jazeera.

He also raised concerns about who would pay for the cleanup. “These illegal tankers don’t comply with the ‘polluter pays’ principle,” he said. According to D’Elia, this creates a major problem because the normal system requires the responsible party to finance the response, as reported by Al Jazeera. 

The second concern is the delay. The tanker suffered damage in early June, but the oil continued to spread for weeks before reaching the mainland. Greenpeace had warned last week that the spill was close to becoming an environmental disaster, reported Al Jazeera.

The longer oil remains in the sea, the greater the area that responders may have to protect. Weather and sea conditions can also make containment harder.

The region’s seasonal conditions add another challenge. Monsoon conditions have complicated cleanup efforts, reported Reuters. Winds and currents can push the slick towards new areas before response teams can contain it.

The protected marine environment around the Hallaniyat Islands makes the situation even more serious. A spill that reaches sensitive habitats can cause damage that takes years to repair.

The Caroline Bezengi travelled from Russia through the Suez Canal, the Red Sea and waters near Yemen before reaching Oman.

No official has issued an explanation regarding the suspected explosion near Yemen. No party has claimed responsibility for an attack on the vessel.

British maritime security company Vanguard told AFP that the tanker suffered explosions in early June and that water entered several sections of the vessel. The ship later ran aground off Oman.

The vessel’s connection to Russia’s shadow fleet has also raised questions about maritime safety. Shadow-fleet ships often operate outside the insurance and regulatory systems used by mainstream international shipping.

The tanker carried sanctioned Russian oil. Such vessels have faced criticism over their age, maintenance standards, insurance arrangements and safety practices, reported Reuters.

The situation also comes amid wider attacks on commercial shipping in the region. The Caroline Bezengi travelled through waters affected by conflicts involving the United States, Iran, Israel and Yemen’s Houthi movement.

The International Maritime Organization has monitored the wider maritime security situation. According to information cited by Al Jazeera, the organisation has been closely following the oil leakage.

A separate oil spill has also affected Iran’s Qeshm Island in the Strait of Hormuz. Iranian state media reported that oil pollution reached parts of Qeshm’s southern coast and nearby Hengam Island.

Iranian Foreign Ministry spokesman Esmaeil Baghaei said pollution appeared at three locations and on the sea surface, reported Al Jazeera. He said the source appeared to be a “foreign bulk carrier”, without identifying the vessel.