More than 1,500 commercial vessels stranded by the closure of the Strait of Hormuz could pose an unexpected environmental threat when they eventually resume sailing, with scientists warning that the ships may transport invasive marine organisms around the world.
Research published in the journal Biological Invasions highlights the risk from biofouling, the accumulation of microorganisms, algae and small marine animals on ships’ hulls. Such growth can accelerate when vessels remain stationary in the same waters for prolonged periods.
More than 1,500 large vessels have reportedly been stranded since the Strait of Hormuz was closed on February 28 amid the US-Iran conflict.
Scientists warn that the prolonged gathering of ships creates unusual conditions for biological exchange. Local marine species can colonise vessels waiting in the region, while organisms already carried on ships arriving from different parts of the world can potentially mix.
Once the vessels disperse and return to international shipping routes, they could carry these organisms to ports and marine ecosystems across the globe, increasing the risk of invasive species becoming established in new environments.
Professor Mario Tamburri of the University of Maryland, lead author of the study, described the concentration of stationary vessels as a “worst-case scenario” compared with previous incidents in which ships were delayed for extended periods.
Researchers fear the eventual simultaneous departure of so many vessels could effectively create a global “super-spreader” event for marine biological invasions.