A new white paper released by Swedish technology company I-Tech highlights the increasing problems for ship operators caused by biofouling occurring during growing idling periods, showing how ship idling has increased over the last 12 years.

The white paper, based on research from I-Tech and Marine Benchmark, draws upon the former’s experience in developing the antifouling agent Selektope® – a component of an increasing number of antifouling products, and takes a deep dive into why idle ships are at risk of biofouling, and the impact of barnacle fouling on vessel performance.

Based on in-depth analysis of the global fleet patterns, the paper reveals the substantial increase in the numbers of idling vessels over the past decade. I-Tech found that ‘Fouling Idling’, as defined in the study, has increased constantly since 2009, with a starting point of 25.4% to a peak of 35.0% in May 2020. Given the growth of the fleet, this means that the absolute number of vessels idling in the global fleet has doubled between 2009-2020.

Significantly, it also finds that vessels are increasingly idling in so-called biofouling ´hotspots´, with water temperatures above 25°C. Vessels spending the majority of their time sailing in these regions are at acute risk of excessive hard fouling accumulation.

This level of fouling was exacerbated by idling patterns seen in 2020, which provided ideal conditions for fouling to grow. For instance, at the peak of idling last year, almost half of all container vessels at fouling idling had long idling periods of more than 30 days, exposing the vessels´ hulls to an extreme risk of hard fouling.

To make matters worse, these fouling windows could intensify as ports become more congested. Furthermore, with global ocean temperatures rising, biofouling hotspots could become more widespread, meaning that more ships could find themselves in one of the regions and facing a new, higher risk of barnacle fouling colonization. 

An earlier study by I-Tech and the Safinah Group shows over 40% of vessels surveyed in 2019 had a barnacle fouling coverage on the hull of over 10%. This level of biofouling, before taking into account idling in 2020, could be responsible for at least 110 million tonnes of excess carbon emissions annually.

As the study demonstrates, although shipping is beginning to play its part in combatting global warming, as evidenced by the IMO GHG Roadmap and regulations such as EEDI, EEXI, and CII, as well as efforts by individual owners to switch to low emission fuels, unpredictable events can still disrupt these decarbonisation efforts, as the study finds. The great financial crisis in 2008, and the oil price crash of 2015, caused similar levels of idling.

Commenting on the outcome of their findings, Philip Chaabane CEO I-Tech, said:

“External factors such as the economic collapse of 2008, the offshore crisis in 2015 and most recently the COVID pandemic and consequent port congestion will always have some disruptive effect on operations and make predictions difficult.

“Ship operators must, however, take action to minimise their impact. Most importantly, they must ensure that, after any idling, the vessel is in good condition to perform optimally. Familiarisation with the individual vessel’s risks of biofouling based on its operating footprint is a good starting point.”

Chaabane pointed out that when looking at the future trading potential, ship operators need to ensure that their ship is protected, whether it is in constant active service, idle for long periods of time, or at risk of fluctuating between the two.

He continued:

“This future-proofing approach to antifouling coating selection, without any certainty of future trade, is exerting great pressure on the coating suppliers, fostering innovation and new approaches towards fouling prevention technology using the active substance Selektope. This is supported by increasing demand from ship owners and operators for antifouling coatings that contain the anti-barnacle active agent.”