Persian Gulf oil spills quadruple in area, satellites show

Persian Gulf oil spills have grown sharply since the Iran war began, according to a new satellite study by researchers at the University of South Florida.

The team compared images from February and March 2026 with the same months in 2025. Spills covered about four times as much area in March 2026 as a year earlier.

What the Persian Gulf oil spills study found

Brian Barnes, a research assistant professor and co-author, called it “a huge expansion of the oil footprint.” He said the team knew some change would show up, but it did not expect the scale.

Part of the pollution probably leaked from tankers stuck behind the shut Strait of Hormuz. Roughly a fifth of the world’s oil usually flows through that narrow passage, so Persian Gulf oil spills carry global weight.

The researchers saw thick slicks from vessels leaking inside the strait. They also found persistent spills around oil infrastructure and near sunken ships.

Cleanup of the continuing leaks is hard while fighting goes on. Persian Gulf oil spills also threaten delicate coasts, among them the Hara Mangrove Reserve beside the strait.

How the team tracked the slicks

The lab used NASA satellite data and combined three types of sensors. Radar, optical imaging and thermal infrared readings showed where the oil sits, how thick it is and whether it has mixed with water.

A paper on the work is under peer review at the Marine Pollution Bulletin. The same lab helped monitor the 2010 Deepwater Horizon spill, and satellite images have improved a lot since then.

Barnes said he wanted sharper techniques because on-site checks are impossible during hostilities. In his view, the war debate had left out the environment, which satellites can now measure.

Other evidence from the Gulf

Earlier satellite reports pointed the same way. Slicks have multiplied since late February. Experts said attacks on ships or energy sites could cause them, and so could mistakes while loading fuel.

The largest slicks that analysts detected came from Kharg Island, Iran’s main oil export site. Estimates ranged from 300 to 3,000 barrels on May 6, and 200 to 2,000 barrels on May 16.

Another slick began near Lavan island, after a strike on the oil refinery there around April 9 or 10. It later reached Shidvar, an uninhabited nature reserve that shelters birds and corals.

A smaller leak followed on May 4 in the strait, after reports of an attack on the tanker Barakah, which ADNOC owns. That slick covered 33.2 square kilometres.

Exact volumes remain unknown, because satellite images cannot show how much oil escaped. Marine scientists also warn that the Gulf’s young coral and other life already face extreme heat and high salt levels.

Liz Atwood, who works as a senior scientist at the Plymouth Marine Laboratory, warned about slicks that drift toward land. Birds, fishing resources and local communities would all suffer, she said.

For now, the Persian Gulf oil spills add an environmental cost to the war, and researchers say they cannot reach the sites to measure the damage on the ground.