The United States-Israel war on Iran has disrupted global supplies of energy, fertilisers, medicines and even helium, devastating economies around the world.

Now it’s also threatening whales off the coast of South Africa.

Fighting involving the Houthis had already turned vessels away from the Red Sea and Suez Canal since 2023. Now the rival restrictions on transit through the Strait of Hormuz, imposed by Iran and the US, have amplified that shift.

But the rising volume of shipping traffic near South Africa’s coast has “substantially increased” the risks of whales being struck, researchers have warned.

That’s according to a study presented this month at a meeting of the International Whaling Commission (IWC), which noted that South Africa’s southwestern coast is increasingly busy, affecting the area’s significant populations of whales.

Why have shipping routes shifted?

Traffic in the Red Sea area was initially disrupted back in November 2023, when Houthi rebels began targeting vessels sailing the area in solidarity with Palestinians amid Israel’s genocidal war on Gaza.

More recently, the attacks on vessels in the Strait of Hormuz, which is currently blocked by Iran, have also caused shipping companies to reroute vessels from the Middle East to go around South Africa’s Cape of Good Hope.

The disruptions have almost doubled the traffic in the area. At least 89 commercial vessels sailed around Southern Africa between March 1 and April 24, according to the International Monetary Fund’s PortWatch Monitor. In the same period in 2023, there were only 44 vessels.

What are the whales that might be affected?

South Africa’s waters are home to more than 40 whale species. The Cape of Good Hope, the country’s southernmost tip, is known to host populations of southern right whales, humpback whales, and Bryde’s whales. There are also Orcas or killer whales, sperm whales, Minke whales, and dolphins in the area.

Large super-pods of humpback whales feed in the area and travel from there on an annual migration to Antarctica. Authorities say they are the largest groups of humpbacks known on Earth. Some studies put their total numbers at between 11,000 and 13,000.

Many species were threatened by commercial whaling in the 20th century. Although the southern right and humpback whales have recovered, others, such as the Antarctic Blue, Fin, and Sei whales, are still listed on the South African Red List as Endangered or Critically Endangered.

How are whales affected?

Whales are directly affected by the increased traffic, as it increases their chances of being struck by a moving vehicle.

“There have been videos of people on cargo vessels that were going through high densities of humpback whales,” researcher Els Vermeulen of the University of Pretoria told the AFP news agency.

Vermeulen, who led the study presented at the IWC meeting, said in such cases, whales are not often aware of the danger, and could be distracted by feeding.

“Obviously, their social media post was all about, ‘Wow, look how many nice whales we see,'” Vermeulen said. “My heart stopped – you know that they’re striking a couple of whales.” Fast traffic, which poses the greatest risks, has quadrupled, she added.

Whales don’t yet know how to adapt to ships, Chris Johnson, the global lead of the World Wildlife Fund’s Protecting Whales and Dolphins Initiative, said.

“You assume that, if you hear a loud noise, you leave. But that’s not the case with some species,” he said. For example, when Blue whales in Los Angeles hear a ship approaching, they just sink below the surface, he added.

Whales are also at risk because of their behavioural changes, which some experts have attributed to climate change and other factors. The humpbacks in South Africa, for example, only started feeding off the west coast, which is growing increasingly busy, in 2011, said Ken Findlay, a blue economy consultant who contributed to the report.

Has the risk of ships striking whales been growing?

It has, researchers say, because of increased human activity.

Vermeulen and her team had previously conducted a study on deaths among southern right whales (SRW) in the Western Cape Coast area back in November 2022, after observing increasing human activity in the area, such as fishing. They solely used data collated by government agencies.

The results, published in the IWC Journal of Cetacean Research and Management, found that between 1999 and 2019, there were 11 fatal ship strikes out of a total of 97 deaths. There were another 16 ship strikes that did not clearly lead to death.

While entanglement in fishing gear was the biggest cause of death, the researchers concluded that deaths from ship strikes are likely undercounted – whales hit by ships in the open seas often sink to the bottom of the ocean.

Can the whales be protected?

Some suggestions from the report presented by Vermeulen’s team to the whaling commission proposed that even small shifts of the traffic lanes away from the coast of South Africa could reduce the risk of strikes to some whale species by 20 to 50 percent.

Whale populations in other parts are also at risk and need protection.

One company, the Swiss-based MSC, has already begun re-directing its ships to protect critical whale habitats, notably around Greece (Hellenic Trench) to protect sperm whales and off Sri Lanka to protect blue whales.

Experts say measures like speed reduction programmes, which significantly lower the risk of lethal collisions and reduce underwater ocean noise, can help.

Researchers are similarly testing if ships could be alerted to the presence of whale super pods via radio messaging or specially-designed apps.

South Africa’s Environment Ministry told AFP that “all available solutions and mitigation measures will be examined” to protect the whales in the Cape of Good Hope.

“Once the scientific studies and assessments have been completed, the maritime authorities will be on the front line, alongside the (ministry) to chart the way forward,” it said.