OVER 1,500 IDLE SHIPS IN HORMUZ STRAIT RISK SPREADING INVASIVE MARINE SPECIES

More than 1,500 commercial vessels remain stranded in the Strait of Hormuz following the closure of the shipping route, creating conditions for a widespread marine invasive species event, according to a study published on 22 July in the journal Biological Invasions. Scientists warn that organisms colonising the idle ships' hulls—including algae, barnacles, mussels and other invertebrates—will spread globally once the vessels resume normal trade routes. Mario Tamburri, a professor at the University of Maryland Centre for Environmental Science and first author of the study, described the situation as "the unprecedented scale and duration of this spring and summer mass lay-up of large commercial vessels" creating ideal conditions for a marine invasive species "super-spreader" event.

The Strait of Hormuz closure followed military strikes on Iran on 28 February, after which Tehran restricted shipping traffic through the waterway, which facilitates the transport of 20% of the world's oil supply according to the U.S. Energy Information Administration. Research indicates that marine organisms begin colonising ship hulls aggressively after approximately 10 days of inactivity, as protective coatings degrade. Carolyn Tepolt, a co-author of the study from Woods Hole Oceanographic Institution in Massachusetts, noted that invasive marine species have "profound ecological and economic impacts on coastlines across the globe" and are "extremely difficult, if not impossible, to eradicate once they become established."

The study cites zebra mussels in the Great Lakes as an example of the environmental damage invasive species can cause. Researchers warned that harmful algal blooms, including the non-indigenous microorganism Margalefidinium polykrikoides, have already become a "recurrent and escalating issue in the Gulf region" near the Bandar Abbas and Qeshm Oil Terminals. Scientists emphasise that whilst the humanitarian and economic effects of the strait's closure remain the immediate focus, an unfolding ecological crisis demands attention.