Maritime environmental regulations have become increasingly prominent internationally as concerns over climate change and air pollution intensify. The shipping industry is under mounting pressure from governments, environmental organizations, and the public to reduce its environmental footprint. This pressure is compounded by the complexity of navigating a rapidly evolving regulatory landscape, making compliance a critical and challenging priority for maritime stakeholders. International cooperation has been essential in shaping these regulations, as countries and organizations work together to establish unified standards and enforcement mechanisms.

Specifically, the International Maritime Organization (“IMO”) has introduced several amendments to MARPOL Annex VI (emissions) that are entering into force within the next few months and are expected to significantly influence vessel operations and compliance strategies worldwide. These regulatory developments are expected to have far-reaching effects on global shipping practices, driving innovation and operational changes across the industry. Below is a selection of recent and upcoming maritime emissions-related regulatory developments, which demonstrate the global impact and growing importance of these regulations.

The Mediterranean Sea Emissions Control Area

The Mediterranean Sea became an Emissions Control Area (“ECA”) on May 1, 2025, under MEPC.261(79), which reduced the maximum sulfur content allowed in marine fuel from 0.5 percent to 0.1 percent. The Mediterranean Sea is the fifth designated ECA, joining the Baltic Sea, North Sea, North American Area, and U.S. Caribbean Sea Area. 

Looking further ahead, on March 1, 2026, under MEPC.392(82), the Norwegian Sea and Canadian Arctic will be designed as ECAs with respect to nitrogen oxides, and on March 1, 2027, one year after the amendments enter into force, with respect to sulfur oxides and particulate matter. 

Other Amendments to MARPOL Annex VI

On August 1, 2025, additional amendments to Annex VI under IMO Resolution MEPC.385(81) regarding fuel sampling, bunker delivery notes (“BDN”), major engine conversions, and fuel consumption data sharing enter into force. 

Fuel Oil Sampling and Bunker Delivery Notes

The fuel oil sampling and BDN requirements are of particular importance to shipboard personnel and bunker suppliers. These amendments clarify the definitions of fuel oil (any fuel delivered to and intended for use on board a ship) and gas fuel (a fuel oil with a vapor pressure exceeding 0.28 MPa absolute at a temperature of 37.8°C). They also provide exemptions for in-use onboard sampling points for low-flashpoint fuel[1] and gas fuel (Regulation 14.12), and require the BDNs for gas and low-flashpoint fuels to meet the informational criteria listed in Appendix V to Annex VI (Regulation 18). 

As of August 1, 2025, a BDN for low-flashpoint fuel and gas fuel will be required to state:

• Name and IMO Number of receiving ship;
• Port where fuel is received;
• Date of commencement of delivery;
• Name, address, and telephone number of fuel supplier;
• Product name(s);
• Quantity in metric tons;
• Density determined by a method appropriate for the fuel, including the temperature;
• Declaration signed by the supplier that the fuel meets the fuel quality requirements of MARPOL Annex VI Regulation 18; and
• The sulfur content of the fuel specifically for use on board as tested by an appropriate method, or a statement that, when tested by an appropriate method, the sulfur content is less than 0.001 percent m/m.

The new requirement for low-flashpoint and gas fuels could lead to potential non-compliance if not carefully followed. It is therefore essential to ensure BDNs include all the required information. 

Pursuant to MEPC.1/Circ.795/Rev.8, electronic BDNs are acceptable and should be protected from edits, modifications, or revisions and can be authenticated by a verification method such as a tracking number, watermark, date and time stamp, QR code, GPS coordinates, or other means. A BDN must be retained onboard for at least three years from the date of delivery and made readily available for inspection as required.

BDNs are also critical for emissions reporting, particularly to the IMO Ship Fuel Oil Consumption Database (Regulation 27), as explained further below. Reporting incorrect or inaccurate fuel types and their corresponding Emission Factor can affect a vessel’s overall Carbon Intensity Indicator calculation. Therefore, shipboard officers and bunker suppliers must ensure accuracy and completeness at the time of each delivery. 

Collection and Reporting of Ship Fuel Oil Consumption Data

As required by MARPOL Annex VI, Regulation 27, all ships of 5,000 gross tonnage and above have been required to collect fuel oil consumption data since 2018 and to report this data to the IMO starting in 2019. The collection criterion are listed in Appendix IX of MARPOL Annex VI. Notably, MEPC.385(81) also adopted amendments to Appendix IX, “Information to be submitted to the IMO Ship Fuel Oil Consumption Database.” These amendments require vessels, starting on August 1, 2025, to report information beyond the existing requirements, including fuel oil consumption per consumer type (main engines, auxiliary engines, oil-fired boilers, and others), both generally and while not underway. Vessels must also report the total amount of onshore power supplied (in kWh), and, on a voluntary basis, the laden distance traveled. Therefore, shipowners and operators should ensure compliance with the added data collection information.

Conclusion

The evolving landscape of maritime emissions regulations underscores the increasing global commitment to reducing the environmental impact of shipping. With the introduction of new ECAs, such as the Mediterranean Sea, and forthcoming designations in the Norwegian Sea and Canadian Arctic, the industry faces new requirements for fuel quality, emissions reporting, and operational transparency. Amendments to MARPOL Annex VI, including expanded bunker delivery note requirements and enhanced fuel consumption data collection, reflect the IMO’s drive for greater accountability and innovation within the sector. As these regulations come into force, shipowners, operators, and bunker suppliers must prioritize compliance and adapt to the complexities of the new standards. Proactive engagement with these regulatory changes will not only mitigate the risk of non-compliance but also position maritime stakeholders at the forefront of sustainable shipping practices, supporting both environmental stewardship and long-term industry resilience.