Iran War Reroutes Shipping, Doubling Vessel Traffic Near South Africa and Raising Whale Strike Risk

### Context The United States‑Israel conflict with Iran has choked the Strait of Hormuz, a key oil and cargo corridor. Simultaneously, Houthi attacks in the Red Sea have kept vessels away from the Suez Canal. Shipping companies now steer around the Cape of Good Hope, sending far more ships past South Africa’s southwest coast.

### Key Facts - Between March 1 and April 24, 2024, at least 89 commercial vessels passed Southern Africa, up from 44 in the same period a year earlier, according to the IMF’s PortWatch Monitor. - The International Whaling Commission (IWC) presented a study showing that this surge endangers the region’s whales, which include southern right, humpback, Bryde’s, orca, sperm and minke species. - Humpback super‑pods—groups of 11,000‑13,000 individuals that feed off the western coast—are especially vulnerable. Researchers have documented videos of cargo ships cutting through dense whale aggregations. - University of Pretoria researcher Els Vermeulen, who led the IWC study, said the footage made her “heart stop” because the vessels appeared to strike whales. - Fast‑moving traffic, the greatest strike risk, has quadrupled, she added. - Earlier work published in the IWC Journal of Cetacean Research and Management found 11 fatal ship strikes among 97 southern right whale deaths (1999‑2019) and 16 non‑fatal strikes.

### What It Means The rerouted traffic creates a “substantial increase” in collision risk, according to the IWC report. Whales cannot reliably detect or evade fast ships; some species simply dive deeper when they hear a vessel, offering no protection against a hull impact. The surge also compounds existing threats such as fishing‑gear entanglement and climate‑driven habitat shifts that have already pushed humpbacks into busier waters since 2011.

Conservation groups warn that without mitigation—such as speed limits, rerouted lanes or real‑time whale detection—fatal strikes could rise sharply, undoing decades of recovery for southern right and humpback populations. Monitoring efforts will need to expand quickly to track strike incidents and assess the effectiveness of any new regulations.

What to watch next: International regulators are expected to discuss speed‑restriction proposals at the upcoming IWC meeting; their adoption could shape the future safety of South Africa’s whales.