As the Iran war enters its ninth week with no clear end in sight, shipping traffic in the Persian Gulf and the Strait of Hormuz has been completely restructured, causing major disruption to global markets and supply chains for oil, natural gas, fertilizers and other essential goods.
Before the United States and Israel launched attacks on Iran in late February, about 3,000 ships typically passed through the Strait of Hormuz every month, according to Lloyd’s List Intelligence. The passing oil tankers account for an estimated 15 million barrels a day of exports of crude oil and other petroleum products, about one-fifth of global oil trade, according to data from analytics firm Kpler.
However, traffic has decreased only slightly since the war began, with only 154 vessels recorded in the entire month of March, according to Kpler data.
“The disruption is rapid and unprecedented,” said Dimitris Ampatsidis, Maritime Risk and Compliance Manager at Kpler.
Overall, traffic through Hormuz in the past two months has been about 5% of the pre-war average, leading to a shortage of refined products, especially in Asia.
Despite the dramatic disruption, a small number of ships still enter and exit the Persian Gulf via the strait. But experts say there are more ships leaving than entering, indicating that shipping companies are reducing risk by avoiding the area entirely and redistributing shipping flows.
“There are still over 800 ships in the bay, and the word ‘stranded’ is not appropriate for all of them,” Ampatsidis told CNN in an email. “Many regional vessels, particularly Iranian and Gulf operators, continue to operate normally within regional routes.”
The strait, about 34 miles across at its narrowest point, has become a chokepoint that Iran can use to tighten its control over global shipping and threaten ships without having to patrol large areas.
Following the ceasefire agreed on April 8, Iranian Foreign Minister Abbas Aragushi initially said safe passage through the Strait of Hormuz was possible with coordination with Iranian authorities. But the next day, Iran’s Islamic Revolutionary Guards Corps (IRGC) claimed traffic in the strait had been suspended again following a ceasefire violation by Israel in Lebanon.
The Revolutionary Guards subsequently published a map showing what it called an “alternative route of transit” through Iran’s territorial waters and the Strait of Hormuz, directing traffic through Larak Island and allowing checks by Iranian navy and port authorities. The Revolutionary Guards also established a so-called “danger zone” in a part of the strait that was previously a major shipping route for the International Maritime Organization (IMO).
“Official IMO shipping routes have been almost completely abandoned. Instead, most ships now use shipping routes along the Iranian coastline,” Ampatzidis said. “At the same time, a significant proportion of traffic remains ‘dark’, meaning vessels are operating outside verifiable corridors.”
Meanwhile, Iranian state media reported on the country’s plans to continue charging transit fees to some vessels seeking passage, as it would be advantageous for Iran to try to maintain control of the waterway.
In response to Iran’s actions, the United States on April 13 announced a blockade of ships entering and exiting Iranian ports and coastal areas. Since the blockade began, the U.S. military has directed at least 38 ships to turn around or return to Iranian ports, according to U.S. Central Command.
Still, most of the ships that have passed through the Strait of Hormuz in recent days took routes designated by Iranian authorities, and about half of them defied the U.S. blockade and loaded cargo at Iranian ports, according to the latest shipping data.
Iranian ports are typically far from the Persian Gulf’s busiest ports, and ports in Saudi Arabia and the United Arab Emirates typically have much higher traffic volumes. But these countries and other Gulf allies have been forced to cut production amid shipping disruptions and threats from Iran.
Importing countries, especially in Asia, are also suffering as they face fuel shortages.
“Japan and South Korea were big importers of Saudi Arabia and Middle East crude. And, you know, if you look at the rest of Asia outside of China, you see a huge impact and loss on the import side,” said Ioannis Papadimitriou, chief cargo analyst at data firm Vortexa.
Papadimitriou noted that the shipping industry as a whole is trying to increase exports from alternative regions to keep oil moving and, importantly, jobs.
“If the situation persists, there will be barrel losses that cannot be replaced anywhere,” the Vortexa analyst added. “Here we see the real loss of cargo. It’s going to hit the shipping industry hard and drive down (freight) rates.”
