A study published in the journal "Biological
Invasions" says marine organisms accumulating on ship hulls during
extended stationary periods may be transported to ports worldwide once traffic
resumes, potentially creating a "super-spreader" effect for invasive
species.
The study found that biofouling, consisting of marine
microorganisms, algae, and invertebrates, can rapidly develop on the hulls of
ships that remain stationary for extended periods.
According to the study, more than 1,500 large commercial vessels
have becomes stranded following the closure of the Strait of Hormuz on February
28, 2026.
The prolonged presence of these ships in the region allows
local organisms to colonize their hulls, while also bringing together
communities of organisms from different parts of the world on the same vessels.
Professor Mario Tamburri of the University of Maryland, the
study's lead author, described the current situation as a "worst-case
scenario" compared to previous shipping disruptions.
The risk is amplified by several converging factors: the
unprecedented number and size of stranded vessels, combined with the fact that
the closure coincides with spring and summer—peak seasons for marine organism
growth and reproduction.
Organisms native to the Gulf, already adapted to extreme
temperatures and high salinity, may prove particularly resilient when
introduced to new environments.
Tamburri said the length of time a vessel remains stationary
is critical in determining the amount and diversity of biofouling.
“The longer they remain stationary during periods of
productive growth and reproduction, the more extensive and diverse the
biofouling on the ships becomes,” he said.
The study stresses that vessels in the Gulf have remained
stationary far longer than normal port waiting periods, creating favorable
conditions for invasive species to reproduce on their hulls and be transported
to other regions.
Tamburri said it is difficult to predict with certainty
which species will be spread by ships, as the risk depends on numerous
variables involving both the species and the environmental conditions to which
they are transported.
The study also notes that species transported through
biofouling can affect not only ecosystems but also economic activities, while
certain parasites and pathogens may threaten commercially important species.
The study emphasizes that the first ports visited by ships
departing the Strait of Hormuz are particularly important for the establishment
of invasive species.
The researchers recommend cleaning the biofouling from
ships’ hulls before they leave the Gulf as the ideal solution.
However, they note that applying this measure to every
vessel would be difficult because the region has limited capacity for such
operations and ships may need to leave quickly for security, logistical, and
operational reasons.
The study identifies specific ports facing elevated invasion
risks due to short voyage times and similar environmental conditions. Jeddah,
Mumbai, Colombo, Singapore, Alexandria, Piraeus, Algeciras, and Rotterdam are highlighted
as particularly vulnerable first destinations.
The Asian green mussel, native to the Gulf, serves as a
cautionary example—having already established itself in Florida, the Caribbean,
Australia, and South America, where it competes with native species and clogs
industrial infrastructure.
Researchers warn that the international maritime community
remains ill-prepared for this biosecurity threat. While regulations are being
developed through the International Maritime Organization (IMO), they will take
years to finalize.
The study recommends implementing early-warning and
rapid-response systems at first ports of call, alongside coordinated
international efforts bridging biological invasion science, maritime logistics,
and regulation.
