Oman said Monday that it is working to contain an oil spill off its southern coast after a tanker ran aground in June inside a protected marine area, triggering calls for action by environmentalists.
It follows an investigation by AFP that found the ship had been stranded for weeks near al-Qibliyyah island after it was rocked by explosions.
The ship has been identified as the Caroline Bezengi.
The Oman Environment Authority said Monday that the ongoing spill had affected roughly 390sq km, according to its most recent analysis.
The slick was concentrated around Oman's Hallaniyat archipelago off the country's southern coast, where a marine reserve was established last year to protect sensitive ecosystems home to diverse marine life, including rare sea turtles.
The country's environment authority said rapid action is needed to protect the area's biodiversity, including "coral reefs, turtle nesting areas, marine habitats and coastal areas of ecological importance".
A report in the state-backed Oman News Agency quoted an official with the transport ministry as saying that authorities were conducting aerial surveillance and had deployed divers.
The official said authorities are in the early stages of developing a plan to transfer the vessel's oil cargo "to reduce the risks arising from the incident, ensure navigational safety and protect the marine environment".
A spill of this scale requires dispersant be sprayed across the affected area by aircraft and the use of booms and other equipment to collect the oil before it reaches the shore or sinks to the sea floor, said Tony Gutierrez, professor of environmental microbiology and biotechnology at Edinburgh's Heriot-Watt University.
"If this oil is kept offshore, the impact will be much less than if the oil reaches shallower waters and the actual coastline," he said, citing the impact on diverse marine life such as coral, birds and fish.
"You could find oil still there years later. And that's what happened with Exxon Valdez,” Gutierrez said.
“Ten years down the line, there still were remnants of oil," he said, referring to a 1989 spill in Alaska.
Omani authorities have not yet identified the cause of the spill.
However, British maritime security company Vanguard told AFP last week that the tanker was rocked by explosions in early June as it sailed off the coast of Yemen, causing water to enter several sections of the vessel.
Advocacy groups Greenpeace and PAX told AFP that the spill was on the verge of causing an "environmental disaster", saying the tanker was carrying around 1mn barrels of crude.
Last week Greenpeace estimated the slick at around 600sq km, citing analysis of satellite imagery.
An analysis by Reuters of satellite imagery and shipping specialists showed the spill from the stranded 274m (900’) tanker was still spreading at the end of last month, raising concern about possible environmental damage.
The Caroline Bezengi loaded at Russia's Black Sea port of Novorossiysk in April and passed through the Suez Canal at the end of May, ship-tracking data shows.
Built in 2001, it is part of the so-called shadow fleet of older oil tankers used by Russia which lack Western insurance cover and sail under the flags of various nations to obscure their true ownership.
It was listed on public shipping databases as flying the Cameroon flag but was among 39 vessels de-listed from Cameroon’s ship registry in June.
The ship is subject to sanctions imposed by the European Union, Ukraine, the UK, Canada and Switzerland.
Its registered owner is Rentoor Shipmanagement Ltd and its manager is Villar Shipmanagement Ltd, according to LSEG data.
Reuters could not immediately reach those firms, which appear to be based in China.
Tankers have been frequently targeted in the Gulf region over recent months as the US exchanged fire with Iran and its allied proxies.