The ongoing military confrontation between the United States and Iran has increasingly shifted to the sea, with both nations targeting oil tankers and commercial vessels in and around the Strait of Hormuz. This escalation has transformed the waterway into a high-stakes environmental tinderbox, where the risk of catastrophic oil spills threatens the fragile marine life of the Gulf.
On September 8, the United States conducted strikes against five Iranian oil tankers, an action that triggered a retaliatory attack on Jordan’s al-Azraq airbase. These hostilities followed a series of earlier engagements; just three days prior, the US had struck three other Iranian tankers. These actions were reportedly in response to Iran launching ballistic missiles at a US aircraft carrier and a navy destroyer near the strait, as confirmed by US Central Command (CENTCOM). Iran subsequently claimed it had targeted three tankers navigating what it described as an “unauthorised route” within the strait, alongside three additional vessels linked to the United States.
The current maritime standoff has left dozens of vessels in limbo. As of Monday, MarineTraffic data indicated that 42 tankers were waiting to transit the Strait of Hormuz, while hundreds of other ships remained stationary or were moving slowly throughout the Gulf of Oman and the wider region. Of those waiting, 18 are confirmed to be carrying oil. While the precise cargo volume remains unverified, these vessels possess a combined capacity of approximately 1.76 million cubic metres of oil and petroleum products—roughly 11.1 million barrels, or 11 percent of global daily demand—posing a massive environmental risk should these ships be struck or sunk.
The potential for ecological devastation is significant. A major spill could release millions of litres of oil, contaminating coastlines, fisheries, and delicate marine ecosystems. Unlike land-based spills, oil at sea is dispersed by winds and currents, potentially impacting vast areas far from the initial incident. Recent history underscores these dangers; since the conflict began, at least 75 ships have been attacked, resulting in 21 deaths, six fires, and two minor oil spills.
One ongoing incident involves the Caroline Bezengi, which has been leaking oil since running aground 22 nautical miles off the Omani coast in early June following a suspected explosion. Estimates suggest the vessel was carrying 800,000 barrels of oil, with Oman’s Environment Authority warning that the spill threatens 40km of coastline near Ras Madraka and Masirah Island. Additionally, the Liberian-flagged bulk carrier Minoan Pioneer caught fire after being struck by a projectile off Oman on August 3, with satellite imagery later detecting large oil slicks near Qeshm and Sirri Islands.
Researchers Fares al-Momani and Ponnumony Vethamony of Qatar University note that the Gulf has long been one of the most anthropogenically impacted marine regions globally, owing to extensive industrial and coastal development. This history includes the legacy of the 1991 Gulf War, where retreating Iraqi forces ignited Kuwaiti oil wells, releasing millions of gallons of oil that devastated over 770km of coastline and destroyed local ecosystems. Experts warn that current cleanup efforts, much like those in the past, may be forced to prioritize damage control over true restoration.
The Gulf’s unique environment—a shallow, semi-enclosed sea with limited water exchange—makes it particularly vulnerable. It hosts resilient coral reefs, mangroves, seagrass beds, and mudflats that serve as critical nurseries for fish, turtles, and migratory birds. Hussein Samh al-Masroori, an associate professor at Sultan Qaboos University, emphasized that petroleum hydrocarbons directly harm these organisms. He noted that sensitive habitats like coral reefs and mangroves can retain pollutants for extended periods, complicating recovery efforts.
Furthermore, the Gulf’s nearly 65 million residents rely heavily on desalination plants for their water supply. The safety of these plants is now a major concern. “The actual risk depends greatly on the location of the spill, currents, distance and depth of the intake, and treatment technology,” al-Masroori explained. With a study by the University of South Florida finding that oil spills in the region were four times higher in March compared to the previous year, the environmental pressure on the Gulf continues to mount as the military conflict persists. The report also notes that and is equivalent to about 11 percent of the world’s daily oil demand, enough to fill roughly 714 Olympic-sized swimming pools, that — 1.76 million cubic metres of crude oil — is roughly 11.1 million barrels of oil. The report also notes that on September 5, CENTCOM said its forces struck three Iranian oil tankers — one off Kharg Island, Iran’s main oil-export hub; another near Jask; and a third, an unladen tanker, in the Gulf of Oman after its crew was ordered to abandon ship. The report also notes that as well as Masirah Island, oman’s Environment Authority warned that the spill could affect about 40km (25 miles) of coastline near Ras Madraka. The report also notes that while another slick was detected near Sirri Island, satellite imagery taken on August 10 showed a large slick near Qeshm Island. The report also notes that but could not independently confirm its source, experts said the Qeshm slick likely came from the Minoan Pioneer. The report also notes that “The region has undergone drastic economic, social and industrial development, and the coastline has been modified and extensively developed to host desalination plants, power plants, oil rig platforms, refineries, and other coastal infrastructures,” they said, responding jointly in an email.