Over 1,500 ships stranded in the Strait of Hormuz may trigger a biological invasion as marine organisms accumulate on their hulls.
Due to the closure of the Strait of Hormuz, over 1,500 vessels stranded in the Basra and Oman Gulf may create a 'biological invasion super spreader' effect as marine organisms accumulate on their hulls and are transported to different regions once operations resume.
A study published in the journal 'Biological Invasions' highlighted that biological accumulation (biofouling) consisting of marine microorganisms, algae, and invertebrates rapidly developed on the hulls of vessels that remained idle for an extended period.
According to the research, more than 1,500 large commercial vessels became immobilized in the Basra Gulf and Oman Gulf following the closure of the Strait of Hormuz on February 28. The prolonged waiting of these vessels in the region has led to both the settlement of local organisms on their hulls and the congregation of living communities from different geographies on the same ships.
Professor Mario Tamburri, the lead author of the study from the University of Maryland in the United States, stated that the current situation represents a 'worst-case scenario' unlike previous vessel waiting incidents.
Tamburri expressed that the risk arises from several factors occurring simultaneously, stating, 'Firstly, the number and size of the vessels that have remained idle; secondly, it coincides with the spring and summer seasons, which are periods of growth and reproduction for marine organisms.'
Indicating that marine life in the region is resilient to harsh environmental conditions such as high temperatures and salinity, Tamburri noted that these characteristics could increase the likelihood of these organisms becoming invasive when transported to other areas.
Tamburri also emphasized that options for safely and effectively managing biological accumulation on idle vessels in the Gulf region are limited, adding that the risk is further exacerbated by the vessels' ability to reach different ports worldwide after leaving the area.
'The longer ships wait, the more biological accumulation increases.'
Tamburri pointed out that the duration of a vessel's idleness is critical in terms of the quantity and diversity of biological accumulation, stating, 'The longer they remain idle during the productive growth and reproduction period, the more extensive and diverse the biological accumulation on the vessels becomes.'
The study notes that biological accumulation on submerged ship surfaces can enter a rapid growth phase within approximately 10 days, and if vessels remain idle for more than 18 to 30 days, measures must be taken to manage biological accumulation.
The research highlights that vessels in the Gulf have remained idle for much longer than their normal port waiting times, emphasizing that this situation creates suitable conditions for invasive species to proliferate on the hulls of the vessels and subsequently be transported to different regions.
Example of the Asian green mussel
Tamburri conveyed that it is challenging to definitively determine which species will spread through vessels, as the risk is shaped by numerous variables depending on the species and the environmental conditions to which they are transported.
However, he noted that examples such as the Asian green mussel, which is native to the Basra Gulf, illustrate the scale of the current risk, explaining that this species has been transported to Florida and the Caribbean, Australia, and South America, and that the Asian green mussel competes with native bivalve species in some areas and can clog the piping systems of power plants and desalination facilities.
The research also indicates that species transported through biological accumulation can affect not only ecosystems but also economic activities, with some parasites and pathogens posing threats to commercially important species.
Short-distance routes increase risk
The study emphasizes that the first ports of call for vessels departing from the Strait of Hormuz are particularly significant for the establishment of invasive species. Therefore, researchers point out that these vessels could act as 'biological invasion super spreaders' in transporting invasive species to different geographies.
Tamburri attributed the high risk associated with ports such as Jeddah, Mumbai, Colombo, Singapore, Alexandria, Piraeus, Algeciras, and Rotterdam to the relatively short voyages from the Gulf to these ports and the similarity of environmental conditions, particularly in terms of temperature and salinity.
For this reason, researchers recommend the implementation of early warning and rapid response systems at the first ports these vessels will reach after departing from the Gulf.
'The international maritime community is not sufficiently prepared.'
Tamburri stated that the international maritime community is not yet adequately prepared to address the biological security risks that long-term and large-scale vessel waiting periods can create.
Professor Tamburri noted, 'Regulations are being developed through the International Maritime Organization (IMO), but it will take several years for them to be fully prepared and approved. Very little attention has been paid so far to the biosecurity risks that could arise from prolonged and large-scale disruptions in maritime transport.'
He expressed the need to conduct the research, emphasizing that a coordinated international effort is required to mitigate the risks by integrating biological invasion science, maritime logistics, and regulations.
Researchers propose that cleaning the biological accumulation on vessels before they leave the Gulf is the ideal solution. However, it is stated that the limited capacity to carry out these operations in the region and the necessity for vessels to be quickly removed from the area for safety, logistics, and operational reasons make it difficult to apply this to all vessels.
Source: SeaNews Türkiye
