A recent study warns that the current situation of ships being stuck in the Gulf region due to the closure of the Strait of Hormuz could lead to a significant spread of invasive species, posing a severe international biosecurity threat when the vessels eventually resume their journeys. The study, published in Biological Invasions, highlights the risk of algae, barnacles, tunicates, and other organisms accumulating on idle ships in the Persian Gulf and the Gulf of Oman.
Lead author Mario Tamburri, a professor at the University of Maryland Center for Environmental Science, emphasized that the stagnant ships present an ideal scenario for a biofouling event that could facilitate the movement of numerous species across different regions. The closure of the strait, attributed to the ongoing U.S.-Iran conflict, has left approximately 1,500 ships stranded in the Persian Gulf and additional vessels in the Gulf of Oman.
The accumulation of organisms on ship hulls, known as biofouling, could lead to the inadvertent spread of invasive species to various ports worldwide if proper measures are not taken. The prolonged stationary period of ships in the Gulf has disrupted their usual cleaning routines, making hull coatings less effective in preventing biofouling.
Tamburri and his team described the situation as a “worst-case scenario,” with ships remaining idle for significantly longer durations than usual. The sheer number of vessels, their close proximity, and the timing of the closure increase the likelihood of a “super-spreader” event. The warmer waters and favorable conditions for organism growth further exacerbate the risk.
Cleaning the ships before they depart poses a significant challenge, as existing in-water cleaning services are ill-equipped to handle the large volume of ships within a short timeframe. The safety risks involved in sending workers into the water during a conflict further complicate the situation.
While the transportation of species through cargo and ballast water has received attention in the past, the issue of biofouling has been relatively overlooked. The inadvertent transport of organisms on the external surfaces of ships can lead to the introduction of invasive species into new ecosystems, potentially outcompeting native species.
Efforts to address biofouling are gaining traction, with updated guidelines released by the International Marine Organization in 2023. However, mandatory regulations regarding biofouling management are still in progress. The ecological consequences of the current situation in the Gulf highlight the interconnectedness of geopolitical events and environmental impacts, emphasizing the need for global cooperation in addressing marine invasion risks.