Overview
- The closure of the Strait of Hormuz has left roughly 1,500 commercial vessels anchored for weeks to months and researchers say that prolonged stillness has allowed heavy biofouling to build on hulls and propellers.
- A multi‑university study published in July 2026 warns these ships could act as a 'bioinvasion super‑spreader event' by transporting Gulf organisms that tolerate high heat and salinity to ports around the world.
- Scientists recommend pre‑departure in‑water cleaning that captures and safely disposes residues, expanded port surveillance, and coordinated international response but say current global cleaning capacity and disposal plans are insufficient.
- The situation already raises economic and climate costs because even thin slime can raise a ship’s greenhouse gas emissions by about 20–25 percent and heavier fouling can boost fuel use by 30–50 percent or more.
- Demand for specialist hull‑cleaning divers and equipment has surged and per‑ship cleaning bills have climbed sharply, creating a logistical bottleneck that could let fouled vessels sail before biosecurity measures are in place.