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The current closure of the Strait of Hormuz amid the US war with Iran may not only be causing problems for the global economy. Marine scientists are now warning that thousands of vessels stranded in the Persian Gulf could inadvertently introduce an unprecedented wave of invasive species, parasites and pathogens to the region.
The team’s report is presented in a study recently published in the journal Biological invasions. According to the paper’s authors, including Woods Hole Oceanographic Institution (WHOI) marine biologist Carolyn Tepolt, these extremely disruptive newcomers are often “extremely difficult, if not impossible” to remove once they are there.
“This disruption to global shipping has many repercussions and has also more quietly created ideal conditions for spreading warm-water species to new ports,” Tepolt said in a statement.
For centuries, invasive organisms have made their way into unprepared ecosystems around the world, thanks to maritime trade routes and a process known as ship biofouling. Merchant ships inadvertently began exporting the European green crab (Carcinus maenas) during the 19th century, and the voracious crustaceans are now found on every continent except Antarctica. The brown tree snake (Irregular buoy) likely hitchhiked aboard ships bound for Guam during the 1950s and have since hunted several species native to the island to extinction in a matter of decades.
Some of the most disruptive newcomers never reach dry land. Tepolt and the study’s co-authors cite recent problems with Margalefidinio polikrikoidesa bloom of toxic red algae that kills fish and often hides inside a ship’s water ballast before spreading through destination ports. The bay barnacle (Amphibalanus improvisu) can thrive in both high- and low-salinity waters, where they compete with native organisms for resources and block intake pipes at factories and power plants.
What’s more, the climate of the Persian Gulf may further exacerbate the situation. Warmer waters encourage the reproduction of many invasive ocean species, while reinforcing heat resistance in future generations, making them even more difficult to manage.
To stay on top of growing concerns, marine scientists are urging international cooperation to better monitor ship biofouling, while intensifying ship mitigation and cleanup efforts. If routes reopen, global ports, especially those where currently stranded vessels are first arriving, will need to increase their own invasive species prevention protocols.
“While the human and economic consequences of events such as the war in the Middle East will always remain the top priority, the ecological impacts cannot be ignored,” the researchers warned.
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