Port congestion increases biofouling, harming energy efficiency and marine life – study

Biofouling – the buildup of barnacles, plants and algae on ships’ hulls – is only getting worse as waters warm and port congestion increases idle time, according to a recent I-Tech study.

As it accumulates, the biological material adds drag and reduces fuel efficiency, costing shippers money and releasing unnecessary greenhouse gases. The study found that the risk of biofouling buildup increases significantly when a vessel is idling or in warmer waters.

“Fouling happens much faster in warm tropical waters. Vessels exposed to longer periods at anchor awaiting cargo or port access are at greater risk of fouling than those on the move,” said the study by I-Tech, a Swedish company that has developed an antifouling paint ingredient. “Vessels idling for 14 days or more are known to be at high risk of barnacle growth.”

With increasing port congestion in areas such as the West Coast of the United States and the East Coast of China, biofouling is accelerating. The average ship wait time between mooring and docking in Los Angeles was at a record high of 13 days on Wednesday, according to FreightWaves’ latest update on congestion in the region.

Biofouling can start within the first few hours a ship enters the water, according to the International Maritime Organization.

“On average, barnacles can grow by around 0.1mm per day, but it can be even more under the right conditions,” Markus Hoffmann, technical director of I-Tech AB, told FreightWaves. “When a ship’s hull begins to foul, its full impact is only fully realized after weeks of growth. Initially, after their first week of adhesion, smaller barnacles can be removed relatively easily. However, we can only see the full extent of the impact of idling fouling after weeks or even months when the fouling organisms begin to grow.

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Before recent congestion reached critical levels, the study estimated that the number of idling ships had already roughly doubled in the past decade.

The study revealed a negative feedback loop. More biofouling can lead to increased fuel usage and higher emissions, which increases the carbon footprint. More GHG emissions can lead to higher water temperatures, which increases the risk of biofouling.

Cost and Ecosystem Considerations

(Infographic: I-Tech)

“A vessel with only 10% barnacle coverage requires a 36% increase in shaft power to maintain the same speed through the water,” the I-Tech study said.

Since fuel consumption accounts for such a large portion of shipping costs, this increase in drag can significantly reduce profits. Each biofouling-related hull cleaning can cost between $15,000 and $45,000, depending on the study. ECOsubasea, a robot cleaner and biofouling collector based in Storebø, Norway, estimates shippers can save up to 20% on fuel costs when biofouling friction is removed.

But energy efficiency, profits and emissions aren’t the only reasons biofouling is an enemy of the shipping industry. It also brings aquatic invasive species from around the world to unique marine environments where the species can damage local ecosystems.

“The spread of invasive species is now recognized as one of the greatest threats to the ecological and economic well-being of the planet. These species cause enormous damage to the biodiversity and precious natural resources of the earth on which we depend. … Significant economic impact occurs on industries that depend on the coastal and marine environment, such as tourism, aquaculture and fisheries, as well as costly damage to infrastructure,” the IMO said.

The organization recommends routine biofouling management to reduce vessel resistance and mitigate threats to biodiversity. There are several antifouling coatings for different conditions and various cleaning techniques in the industry, although most of these techniques damage the coatings intended to prevent buildup.

I-Tech has developed Selektope, a metal-free organic marine antifouling paint ingredient designed to prevent barnacle larvae from attaching to ship hulls.

ECOsubasea’s robotic biofouling removal solution collects what is removed from ship hulls, including any aquatic invasive species, and brings it ashore to be used as feedstock for biofuels. This gentler removal technique can be performed in water, removes more than 97% of dirt and does not damage the hull’s antifouling coating, according to the company.

“Savings from effective antifouling systems are estimated at over $100 million [metric tons] of carbon dioxide for the entire shipping industry each year,” the study states.

Click here for more FreightWaves articles by Alyssa Sporrer.

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