Barnacles and Biofouling: The New Threat in the Strait of Hormuz

Hundreds of oil tankers anchored in the Persian Gulf face significant delays in resuming operations due to extensive biofouling, a process where marine life like barnacles and algae attach to ship hulls. According to professional divers and maritime industry organizations, clearing these vessels requires specialized labor, as biofoul increases drag, ruins fuel efficiency, and risks spreading invasive species to international ports.

Why Does Biofouling Disrupt Global Oil Shipping?

Biofouling—the accumulation of marine organisms on submerged surfaces—drastically reduces a ship’s hydrodynamic efficiency. According to Neil Roberts of the Lloyd’s Market Association, fuel costs account for roughly 50% of a vessel’s total operating expenses. When a hull is covered in barnacles and mussels, the added drag forces engines to work harder, burning significantly more fuel to cover the same distance. For tankers transporting oil from the Middle East to Asia or Australia, this inefficiency makes the voyage economically unviable. Furthermore, Carolyn Shearlock of The Boat Galley notes that severe growth on propellers can render them completely useless, while intake valve clogs can destroy a ship’s cooling system.

How Do Divers Clean Supertankers?

Cleaning a 300-meter-long supertanker is a labor-intensive process that requires professional underwater intervention. Derek Hamm, a diver with Obsessive Compulsive Divers, explains that a typical crew of five to six workers spends four to five hours per ship using hand scrapers and power washers. According to Brian McCauley of McCauley Mooring and Diving, the challenge lies in the sheer scale of the vessel, which features approximately 14,000 square meters of surface area. Divers must carefully remove biofoul without damaging the ship’s specialized anti-corrosive coating, as damage here can lead to insurance penalties and ecological regulatory violations.

What Are the Financial Impacts for Ship Operators?

The sudden surge in demand for cleaning services has driven costs upward significantly. Aron Sørensen, chief environment officer at BIMCO, reports that bottom-cleaning teams have raised their fees by several thousand dollars, with current charges exceeding five figures per vessel. This expense is only one part of a larger, complex restart for the energy sector. Beyond cleaning, tankers must navigate mine-clearing operations in the Strait of Hormuz, secure financial and insurance approvals, and comply with new registration requirements mandated by Iranian authorities. As a result, industry experts warn that the global oil supply chain will not return to full capacity immediately upon the reopening of the strait.

Frequently Asked Questions

Why can’t ships just sail with barnacles on them?
Biofoul increases drag and fuel consumption, making long-distance shipping prohibitively expensive. Additionally, maritime regulations prohibit ships from entering ports with invasive species attached to their hulls.

How long does it take to clean one tanker?
A crew of five to six divers typically requires four to five hours of continuous work per vessel to clear the hull of buildup.

Is biofouling a new problem for the maritime industry?
No. It is an “age-old problem,” according to Neil Roberts of the Lloyd’s Market Association, who notes that vessels have required anti-fouling measures for centuries to maintain speed and structural integrity.