Tanker Strikes in Strait of Hormuz Trigger Oil Spills Threatening Fragile Ecosystems

The Strait of Hormuz is experiencing a severe environmental crisis as missile attacks and naval warfare disrupt maritime traffic, leading to extensive oil leaks. Experts analyzing satellite imagery have identified telltale signs of contamination, including dark, muddy patches and silvery, reflective sheens on the water’s surface. These visual markers confirm that the ongoing conflict between the United States and Iran is causing significant ecological damage as vessels are struck, ignited, or sunk.

One prominent incident occurred in June when a Russian tanker carrying approximately 800,000 barrels of oil ran aground near the Omani coast, resulting in a major spill. According to Greenpeace, the number of large oil-carrying tankers stranded in the strait has decreased from a high of 85 earlier in the war to 13. However, each immobilized vessel, along with every ship attempting to navigate the waterway, remains at high risk of attack. Since the conflict began, the environmental organization has tracked more than 100 distinct spills using satellite data.

Widespread GPS spoofing in the region, which causes ships to broadcast inaccurate positions, likely obscures the full extent of the contamination. In a report released this week, Greenpeace described the situation as an “ecological catastrophe,” highlighting oil slicks encroaching upon protected and sensitive ecosystems. Nina Noelle, a Greenpeace expert on environmental disaster relief, emphasized the severity of the situation to DW, stating, “People should be concerned.” She noted that the war has inflicted a heavy toll on the environment, with damage now reaching unprecedented scales.

Earlier this week, Greenpeace identified five major oil slicks covering a combined visible area of 240 square kilometers—roughly four times the size of Manhattan. While recent satellite images suggest these surface patches have shrunk to approximately 80 square kilometers due to dispersal by weather conditions, Noelle warned that the ecological threat remains critical. “Oil can also sink into the sediment and impact the ecosystems for years and years,” she explained.

Of particular concern is the proximity of the spills to vulnerable habitats. One slick was detected near Musandam National Park in Oman, a protected area known for its coral reefs, diverse sea life, and vital bird breeding grounds. Another is located near Iran’s Minab River Delta, which features protected mudflats and mangrove forests. Recovery from such damage can take decades.

Accurately assessing the full scope of the spill is difficult. Noelle described the current figures as a “conservative estimate,” adding, “It might be worse. It’s definitely not better.” Researchers rely on publicly available data from the European Union’s Copernicus Sentinel-1 and Sentinel-2 satellites. While private providers like Planet Labs offer higher-resolution imagery, access has been restricted during the war to prevent their data from being utilized for military targeting.

On-the-ground reporting is also limited. Wim Zwijnenburg, an environmental researcher at the Dutch peace organization Pax, noted that both Iran and Gulf states enforce restrictive policies on sharing imagery from shorelines, leaving a gap in real-time information.

The oil poses serious threats to both wildlife and human populations. For sea birds, oil coating their feathers destroys natural waterproofing and buoyancy, impairing their ability to fly, hunt, and stay afloat. Even minor exposure can ruin eggs, preventing hatching or causing deformities in offspring. Mangrove forests, which serve as nurseries for coastal species, are similarly devastated. “Mangroves have aerial roots and the oil is covering these roots like a film and actually hindering the mangroves in exchanging gases,” Noelle said. “They’re kind of suffocated by the oil. Most of the time, it leads to the trees dying.”

Human communities are also at risk. Coastal populations depend on fisheries that suffer mass die-offs after oil exposure. Furthermore, oil contamination threatens drinking water supplies, as Gulf states rely heavily on desalination. Desalination accounts for 90% of Kuwait’s drinking water, 86% of Oman’s, and 70% of Saudi Arabia’s.

Cleanup efforts are hindered by the active conflict. Zwijnenburg stated that military movements and the presence of mines make it extremely difficult to deploy vessels and commence clean-up operations quickly. Environmental groups argue that the rising scale of oil spills serves as further evidence that the world must reduce its dependence on fossil fuels. “The most sustainable long-term damage prevention for things like that would be to reduce and ultimately end our dependency on oil and gas,” Noelle concluded. “Because as long as our energy systems and transport routes are centered around fossil fuels, there will be a continued environmental risk.”