Stricter air & water pollution limits for shipping in Mediterranean

April 30, 2025

Cleaner air and water in the Mediterranean Sea are on the horizon as the Mediterranean Emission Control Area for sulphur oxides enters into effect on 1 May.

It will make the Mediterranean Sea the fifth Emission Control Area (ECA) for sulphur oxides in the world – protected sea areas where stricter controls are in place to minimise air pollution from ships. In the Mediterranean Sea, it means ships will have to use marine fuel with lower sulphur content, down from 0.5% (a global requirement) to a maximum of 0.1%.

Sulphur oxide emissions lead to sea and land acidification and contribute to fine dust, which is linked to respiratory and cardiovascular conditions. Reducing these emissions will improve air and water quality, thereby benefiting human and environmental health.

Sulphur oxide emissions in the EU have decreased by approximately 70% since 2014, primarily due to the establishment of an Emission Control Area in Northern Europe, as reported in the 2025 European Maritime Transport Environmental Report and the 2025 Zero Pollution Monitoring and Outlook Report.

The new Mediterranean Emission Control Area is expected to lead to further reductions. However, during the same period, nitrogen oxide (NOx) emissions in the EU have increased by 10% from 2015 to 2023, with an 8% increase specifically in the Mediterranean.

To address this issue, the European Commission and Mediterranean States are currently assessing the most effective means to reduce these emissions.

The agreement to further protect the Mediterranean’s marine environment by setting up a Mediterranean Emission Control Area was reached by the EU and Mediterranean countries, under the UN’s Barcelona Convention in 2021. The International Maritime Organization (IMO) agreed with the mentioned designation request in 2022.

In April, the IMO also approved a Northeast Atlantic Emission Control Area to reduce both sulphur and nitrogen oxides, due to be adopted later this year, with entry into effect in 2027. It will encompass the EU littoral states, Greenland, the Faroe Islands, Iceland, and the UK.

Speaking on the issue, Commissioner for the Environment, Water Resilience, and a Competitive Circular Economy, Jessika Roswall, said:

“The EU and its Mediterranean neighbours have jointly set up an Emission Control Area to tackle ship pollution at its source. This is a major step towards making our maritime industries cleaner, more competitive, and future-proof. Preserving this marine region is crucial for water resilience, reducing pollution, and protecting the health of coastal communities and their surrounding environment.”

Background

The Mediterranean Sea is under pressure from various threats, including pollution, marine litter, overfishing, underwater noise, invasive species, and seabed disturbance. Establishing the Mediterranean Emission Control Area will help EU Member States stimulate clean competitiveness whilst accelerating compliance with climate and environmental goals. A clean, healthy, and productive sea is essential for a sustainable blue economy and to comply with EU legal requirements.

Maritime transport has a significant impact on air quality, with ship exhaust gases, especially sulphur oxides from fuel oil combustion, being major pollutants. These emissions negatively affect respiratory health and increase sea acidification. By burning fuel with low sulphur content, ship engines emit fewer sulphur oxides.

While the global sulphur cap for marine fuel has been set at 0.5% since 2020, Emission Control Areas enforce a stricter limit of 0.1%. In comparison, the sulphur content in road fuel for trucks or passenger cars is restricted to 0.001%. The Sulphur Directive (2012) played a key role in reducing sulphur oxide emissions by setting sulphur limits in fuel in EU legislation.

Since the early 2000s, Emission Control Areas have been established in ecologically sensitive regions, such as the Baltic and North Seas. By 2014, sulphur oxide concentrations around the Emission Control Areas had significantly decreased, benefiting coastal health without significant economic impact on the shipping sector. The EU initiative’s success in the Baltic and North Seas is set to be replicated with the Mediterranean Emission Control Area and the upcoming one in the Northeast Atlantic.

ECAs contribute to the implementation of EU law, particularly the Sulphur Directive and the Marine Strategy Framework Directive. The latter is the EU’s key tool for marine environmental protection, addressing pressing issues, such as biodiversity loss and acidification, including those caused by sulphur oxides from ships.

It requires EU Member States to develop marine strategies to achieve “Good Environmental Status” and fosters cooperation through Regional Sea Conventions, such as the Barcelona Convention. The most recent evaluation of the Directive was published in 2025.