- 1Lusophone Hub of the Ocean Decade, University of Sao Paulo, Brazil (milena.zuffo@usp.br)
- 2Lusophone Hub of the Ocean Decade, University of Sao Paulo, Brazil (alisson.neves@usp.br)
- 3Lusophone Hub of the Ocean Decade, University of Sao Paulo, Brazil (wduleba@usp.br)
- 4Lusophone Hub of the Ocean Decade, University of Sao Paulo, Brazil (isabela.duleba@gmail.com)
As the global maritime sector advances towards decarbonisation, alternative fuels such as biofuels, hydrogen, and ammonia are increasingly being considered to reduce greenhouse gas (GHG) emissions. However, these fuels pose unique environmental risks, particularly in cases of accidental spills. This study investigates whether the current international legal framework—comprising conventions like MARPOL and the United Nations Convention on the Law of the Sea (UNCLOS)—is sufficient to mitigate and repair environmental damage from spills of these alternative fuels, given that no specific international agreements directly address this issue.
The analysis draws on the complex interplay between maritime law and environmental protection, highlighting that MARPOL’s primary focus has been on regulating traditional pollutants, which limits its applicability to newer fuel types whose chemical properties and ecological impacts vary significantly. According to research by Hsieh and Felby, approximately 70% of fuels in maritime operations must transition to low-carbon alternatives to meet International Maritime Organization (IMO) decarbonisation targets, yet safety data on these new fuels is scarce. Thus, an incident involving such fuels could create challenges for damage quantification, risk assessment, and cleanup protocols (Hsieh & Felby, 2017).
In terms of liability and enforcement, UNCLOS provides a general framework for pollution control, conferring responsibility primarily to flag and coastal states. However, the unique characteristics of alternative fuels, such as ammonia’s toxicity or hydrogen’s flammability, highlight the limitations of existing port and coastal state powers under Articles 211 and 218, which were developed and construed with conventional pollutants in mind (UNCLOS, 1982). Additionally, the IMO’s non-binding guidelines, while useful, do not hold the weight of enforceable international law, leaving significant enforcement gaps when spills involve non-traditional fuels.
This study also considers the “ocean implementation gap” as outlined by Hinds, referring to the lack of inter-agency cooperation among UN organizations tasked with ocean governance, which impedes the development of cohesive regulations for alternative fuel risks. There is a need for fostering UN inter agency cooperation due to their capacity for supporting maritime environmental safety projects (Hinds, 2003). There is also a need for increasing capacity development and ocean research. For instance, only a few initiatives, such as the GreenVoyage2050 project, address the safe use of alternative fuels, leaving major safety concerns unaddressed, as Tandros notes, in terms of fire and explosion risks (Tandros et al., 2023).
In conclusion, while MARPOL and UNCLOS provide foundational frameworks for pollution control, they are not fully equipped to handle the emerging risks associated with alternative fuel spills. The paper recommends establishing legally binding international standards and promoting inter-agency cooperation to bridge the implementation gap. Addressing these regulatory gaps is essential to advancing maritime sustainability and ensuring that the transition to low-carbon fuels does not inadvertently heighten environmental risks.
How to cite: Maltese Zuffo, M., Moraes Neves, A. F., Duleba, W., and Duleba Marques, I.: Assessing International Legal Frameworks for Environmental Damage from Alternative Fuel Spills: Gaps and Future Directions for Maritime Decarbonisation., One Ocean Science Congress 2025, Nice, France, 3–6 Jun 2025, OOS2025-1393, https://doi.org/10.5194/oos2025-1393, 2025.