Marine animals in the Strait of Hormuz do not get a ceasefire

As noise levels rise, whales reduce their diving activity, effectively entering a period of forced fasting that weakens them over time.

From disruption to damage

In the narrow, 21-mile-wide funnel of the strait, military activity creates shock waves and pressure changes that marine species cannot tolerate. Underwater explosions can be powerful enough to instantly kill fish and damage the hearing organs of larger marine mammals.

“Although whales and dolphins may temporarily move outside areas where there is significant marine sonar activity, the intensity of modern maritime conflict poses deadly risks,” notes Aaron Bartholomew, professor of biology, chemistry and environmental sciences at the American University of Sharjah.

Adam warns that the effect could be permanent: “These explosions can also damage the auditory system of cetaceans, which may cause them to lose their hearing temporarily or permanently.” Even when these effects are not immediately fatal, they can weaken animals over time and disrupt their ability to survive in already stressful conditions.

Sea mines pose similar risks even before they explode. When triggered, they generate high-pressure shock waves that can rupture internal organs in fish and damage the auditory systems of marine mammals.

Although some species may try to move away from high-activity areas, this displacement comes at a cost, Bartholomew says. “Whales and dolphins may temporarily move outside areas where there is significant marine sonar activity. Their short-term behavior in the area may be negatively affected,” he says. “Overall, they are likely to be fine. The most likely outcome is temporary displacement from areas that use sonar extensively.”

In a narrow corridor such as a strait, even temporary displacement can interfere with feeding patterns and habitat use, turning short-term disturbance into long-term ecological stress.

“Slow-flowing” nature.

The Arabian Gulf is uniquely vulnerable because it cannot be easily reset.

It is what scientists describe as a “slow-flowing” sea, and it takes between two and five years to completely replace its waters. This means that pollutants – whether from oil, fuel or debris – can persist long after the initial event, spreading across surface ecosystems and the seafloor.

Bartholomew warns that even one large oil spill can have far-reaching consequences: “A large oil spill in the Strait of Hormuz could pollute beaches and severely impact turtle nesting sites, including islands like Sir Bu Neer.”

“Oil spills can kill adult turtles and sea snakes and damage nesting habitats. They can also harm marine mammals such as Indo-Pacific humpback dolphins in Musandam waters (near the strait) and bottlenose dolphins in the Indo-Pacific, as well as killing seabirds.”

The danger is not limited to the surface. Whale sharks that migrate seasonally to the Gulf through the Strait of Hormuz, especially between May and September, are at risk from floating oil because they feed near the surface.

Bartholomew adds: “Although the oil generally floats, storms and high waves can mix it to deeper depths, which could negatively affect coral in the strait area, where coral diversity is the highest in the Gulf, especially on the Iranian side.”

Surface pollution can also change animal behavior in unexpected ways. Oil slicks form shaded areas on the water’s surface, resembling fish aggregation organs, which naturally attract small fish. This can attract other animals – including turtles, sharks and seabirds – to contaminated areas, exposing them to toxins and increasing the risk of them being ingested or encapsulated.