Oil slicks from vessels and offshore oil operations repeatedly drifted into marine protected areas around the world between 2022 and 2025, a new analysis has found. The report raises concerns for important habitats for a variety of marine life, including whales, dolphins, and sea turtles.
Researchers from SkyTruth, a U.S.-based nonprofit that tracks oil pollution using satellite imagery, detected dozens of slicks covering hundreds of square kilometers in protected waters globally.
“We’re seeing persistent, repeated, chronic oil pollution in many parts of the ocean from shipping and offshore oil and gas operations,” SkyTruth CEO John Amos told Mongabay by phone. “Wind and current blow them around out in the ocean, so even if the pollution event that occurs is outside a marine protected area, that pollution could drift into the protected area.”
The worst oil pollution in an MPA was recorded along the Atlantic coast of the Republic of Congo’s Conkouati-Douli National Park. SkyTruth recorded 27 oil slicks covering 880 square kilometers (340 square miles) of the park’s waters. The slicks likely came from three offshore oil platforms located outside the marine park, according to the report. The area is home to sharks, rays, dolphins, whales, and manatees. Leatherback (Dermochelys coriacea) and olive ridley (Lepidochelys olivacea) sea turtles also nest there.
In the Mediterranean Sea, roughly 417 km2 (161 mi2) of oil slicks covered sections of two important marine protected areas. Spain’s Mediterranean Cetacean Migration Corridor registered 45 slicks, all from vessels, the report notes. The Pelagos Sanctuary for the Conservation of Marine Mammals, a reserve shared by France, Italy, and Monaco, registered another 26 slicks.
“It’s one thing to designate an area a marine protected area,” Amos said. “It’s another thing entirely to ensure that that area is well enough monitored and managed to ensure that pollution and other impacts are not negatively affecting the marine protected area.”
Off Romania’s Black Sea coast, 67 slicks covered 263 km² (102 mi²) across two adjacent protected areas: the marine zone of the Danube Delta, and Zernov’s Phyllophora Field, named after a red seaweed that forms underwater meadows there.
According to the SkyTruth report, harbor porpoises (Phocoena phocoena) and bottlenose dolphins (Tursiops truncatus) live in that area of the Black Sea.
“Fundamentally, oil is toxic to marine life,” Amos said.
Oil slicks can contain heavy metals and compounds that can kill or impair the development of organisms at the lowest levels of the food chain, including krill. These contaminants can then bioaccumulate up through the food chain to the largest animals in the sea.
“We’ve got plenty of research showing acute toxicity from exposure to a variety of chemicals in large doses,” Amos said. However, the impacts of chronic low-level exposure are less well understood. “It’s a lot harder to study that.”
Banner image: Oil from the 2010 Deepwater Horizon oil spill. Image courtesy of NOAA.
