Whatever measures are taken, it all begins and ends with a clean hull. Carrying over 80% of world trade by volume, shipping is essential for world prosperity, but it also has a significant impact on the planet; both by its contribution of polluting and greenhouse gas (GHG) emissions and by being the main vector for transferring invasive aquatic species around the globe.

Jotun's Clean Shipping Commitment was first presented at Nor-Shipping in 2023 and is a testament to Jotun’s continuing focus on helping the shipping industry become cleaner. This focus has spanned nearly 100 years and concentrates on solutions and products available in the market today that help the industry to decarbonise while also protecting biodiversity and enjoying fuel saving benefits.

So, what is the difference between green shipping and clean shipping? Green shipping is a commonly used term and includes advanced technical investments and investments in groundbreaking solutions like new types of fuel. However, proven solutions are already available and ensuring a clean hull and good biofouling management are a key step for the industry to become cleaner.

Moreover, a clean hull begins with good biofouling management. Since Jotun was founded in 1926, protecting ships against corrosion and fouling has been at the core of their business. Today, Jotun still believe that a clean hull is a key to reduce carbon emissions, protect biodiversity and preserve fuel.

Decarbonisation: At the IMO, where representatives of the 175 member states devise and adopt regulations for international and domestic shipping under the MARPOL Convention, decarbonisation is at the top of the agenda. 

Indeed, decarbonisation is a term that is used very frequently, and at the IMO, what began as decarbonisation measures are morphing into controlling all greenhouse gases. New ships are given a rating under the EEDI regulations that came into effect in 2013 and which set maximum levels of CO₂ emissions. From 2023, existing ships were taken into a similar regime under the EEXI rules.

In 2023, another new measure—the CII rules—also came into effect. This measure is different and measures the CO₂ emissions of a ship based on its operation over each full year. Once data about fuel use, cargo carried and distance travelled is calculated, the ship will be given a grading from A to E similar to domestic electric appliances.

Adding to the industry pressure to decarbonise is the sustainability pressure on cargo interests, and the impact of shipping has an increasingly visible influence on consumers' decisions. Lastly, financial and insurance institutions have a greater focus on sustainability and a lack of clean measures will affect ship owners’ access to beneficial financial services.

Taken together the international regulations and commercial pressures around decarbonisation puts great pressure on the industry as a whole, and being able to document a clean hull will be of increasing importance.

Protecting biodiversity and transfer of invasive aquatic species has been lifted as another concern, due to the impact on local indigenous species. This has been partially dealt with through the Ballast Water Convention of 2004, which by 8 September 2024 will apply to any ship making an international voyage. Although ballast water was tackled first in the battle against species transfer, studies have shown that biofouling on ships was the main source of invasive species in Australia (70%)¹ and Hawaii (74%)².

The IMO has been working on biofouling since 2006 and this resulted in voluntary guidelines being issued in 2011. The guidelines were updated in 2023 but are still voluntary unless a ship’s flag state makes them mandatory. In the meantime, individual states—Australia is a notable example—require visiting ships to provide information on biofouling management practices prior to arrival and may expel ships which are heavily fouled and deemed to present a risk to biosecurity.

Certainly, invasive aquatic species carried by way of biofouling can have a negative impact, affecting biodiversity, ecosystem health and the livelihoods of coastal communities across the globe. All regulations controlling biofouling will help protect biodiversity in affected areas.

Preserving fuel is something that shipowners strive to do most of the time except when fuel costs are so low that they become irrelevant. That has happened in the past on a very few occasions and, for most of the last half century, fuel costs have been a growing element of ship operation cost. Today bunker fuel can account for as much as 60% of a ship’s running cost. The fact that biofouling increases fuel use and slows ships is something that has been known for centuries. Some operators have been prepared to invest in premium antifouling products and make use of in-water cleaning between drydockings, but they are the exception rather than the rule.

Regardless of arguments that current regulations will become redundant in a future where fuels are effectively carbon free, the economic case for saving fuel by maintaining a clean hull will still be relevant. In fact, e-fuels or other alternatives will be costlier to produce so a clean hull will be even more important.

High-Performing Hull Performance Solutions Address Major Issues

A simple answer to addressing decarbonisation, protecting biodiversity and saving fuel is to ensure the ship hull is as clean as possible at all times. Using high-quality antifouling as well as proactive monitoring and cleaning like Jotun Hull Skating Solutions will prevent biofouling from reaching levels where it will impact ship performance—ensuring that less fuel is needed and thus contributing to significant savings for owners and operators. Less fuel spent has a direct impact on reducing emissions and, last but not least, less biofouling will reduce the spread of invasive aquatic species and protect global biodiversity.

Reprinted with permission from Jotun. For more information, visit https://www.jotun.com/ww-en/industries/shipping. 

References

¹ Australian Quarantine and Inspection Service. 2005. AQIS Fact Sheet.

² Godwin, L Scott (2003). Hull Fouling of Maritime Vessels as a Pathway for Marine Species Invasions to the Hawaiian Islands. Biofouling, 19 (1), 0892 7014.