As noise levels escalate, whales reduce their diving activity, entering a period of forced fasting that weakens them over time.
From disruption to destruction
In the strait’s narrow 21-mile-wide chimney, military activity creates shock waves and pressure changes that marine species are not built to withstand. Underwater explosions can be powerful enough to instantly kill fish and damage the auditory systems of larger marine mammals.
Aaron Bartholomew, professor of biology, chemistry and environmental sciences at the American University of Sharjah, suggests that “while whales and dolphins may temporarily leave areas where there is significant marine sonar activity,” the intensity of newfangled maritime conflict poses deadly risks.
Adam warns that the effects could be long-lasting: “These explosions may also damage the auditory system of whales, which may cause temporary or permanent hearing loss.” Even if not immediately fatal, the effects can weaken animals over time and disrupt their ability to survive in already stressed conditions.
Sea mines pose a similar risk even before detonation. When activated, they generate high-pressure shock waves that can rupture the internal organs of fish and damage the auditory system of marine mammals.
Bartholomew says that while some species may try to leave warm zones, there are costs to moving. “Whales and dolphins may temporarily leave areas where there is significant marine sonar activity. This may have a negative impact on their short-term behavior in the region,” he says. “Overall, they are likely to be unharmed. The most likely effect will be temporary displacement from areas of heavy sonar use.”
In a restricted corridor such as a strait, even momentary displacement can disrupt foraging patterns and habitat operate, turning short-term disturbances into long-term ecological stress.
The nature of “slow flush.”
The Arabian Gulf is uniquely vulnerable because it cannot be easily reset.
Scientists describe the sea as a “slow flush” that takes two to five years to fully replace its waters. This means that contaminants – whether oil, fuel or debris – can persist long after the initial event, spreading throughout both surface and seafloor ecosystems.
Bartholomew warns that even a single major spill could have far-reaching consequences: “A major oil spill in the Strait of Hormuz could contaminate beaches and severely impact turtle nesting sites, including islands like Sir Bu Nair.”
“Oil spills can kill adult turtles and sea snakes and damage breeding habitats. They can also harm marine mammals such as Indo-Pacific humpback whales in Musandam waters [near the strait] and Indo-Pacific bottlenose dolphins, as well as killing seabirds.”
The threat is not limited to the surface. Whale sharks, which migrate seasonally to the Persian Gulf through the Strait of Hormuz, particularly between May and September, are susceptible to floating oil because they feed close to the surface.
Bartholomew adds: “Although the oil generally floats, storms and high waves can mix it at greater depths, which could negatively impact corals in the strait region where coral diversity is the highest in the Persian Gulf, particularly on the Iranian side.”
Surface contamination can also change animal behavior in unexpected ways. Oil slicks create shadowy areas on the water surface, similar to fish collecting devices, that naturally attract tiny fish. This can attract other animals – including turtles, sharks and seabirds – to contaminated zones, exposing them to toxins and increasing the risk of being ingested or covered.