Green Marine Europe at IMO: Advancing the Integration of Energy Efficiency and Underwater Radiated Noise Reduction

On November, 6-7, 2025, Green Marine Europe (GME) took part in the Second IMO Workshop on the Relationship Between Ship Energy Efficiency and Underwater Radiated Noise (URN), held at IMO (International Maritime Organization) Headquarters in London.

This workshop - mandated by MEPC 82 within the IMO Action Plan on Underwater Noise - brought together regulators, researchers, NGOs, classification societies, ship owners and technology developers to accelerate the convergence between noise reduction, energy efficiency, and biodiversity protection.

The two-day event - co-sponsored by IMO and the GEF-UNDP-IMO GloNoise Partnership - highlighted both scientific advances and operational pathways to reduce the acoustic footprint of global shipping, a long-standing environmental priority for GME.

Setting the Scene: Why URN Matters

Underwater radiated noise is increasingly recognised as a critical pressure on marine ecosystems, particularly for cetaceans. Today, shipping is the dominant anthropogenic source of low-frequency ocean noise.

The workshop therefore had a dual ambition:

1. Consolidate the scientific basis linking propulsion, energy efficiency measures, and acoustic emissions.
2. Identify regulatory and operational opportunities to stimulate URN mitigation, including incentives, design standards, and data-driven monitoring.

These aims mirror the long-term commitments of GME, which has been working on URN performance since the creation of the program and now counts more than 30 European ship owners actively reporting on the indicator, including companies operating in the Mediterranean Particularly Sensitive Sea Area (PSSA).

Inside the Workshop: Key Insights and Milestones

Day 1 — Technical Advances & Integrated Management

The first day focused on technological developments, measurement techniques, and the interface between energy-saving devices (ESDs) and noise mitigation.

Highlights included:

• Updates on IMO’s ongoing regulatory workstreams for energy efficiency and URN guidelines (Secretariat and Belgian Correspondence Group).
• Case studies showing how propeller optimisation, hull design, coatings, and VFD technologies can deliver co-benefits for URN and EE.
• Research results from major EU and North American projects illustrating the performance of electric tug and ferry designs in reducing URN.
• A dedicated session on methodologies to identify areas where URN reduction is most effective, anticipating future spatial-management tools.

The afternoon also explored economic models and incentivisation schemes, highlighting the importance of aligning EE and URN objectives in performance standards and financial instruments.

Day 2 — Standards, Predictive Models & Policy Foresight

The second day shifted towards forward-looking frameworks:

• The use of simulation-based ship design to predict URN before construction.
• Integration of noise considerations into ecosystem-based maritime spatial planning.
• Early findings from Canada’s URN management pilot and insights from Maersk on design-stage decision-making.
• Foresight analyses from EMSA exploring URN trends in European waters up to 2050 under different GHG and noise-mitigation scenarios.

Collectively, these sessions demonstrated the growing international momentum toward integrated URN/EE standards, a central step for future IMO regulatory packages.

GME’s Contribution: From Indicators to Incentives

GME’s General Manager, Dr. Antidia Citores, delivered a presentation titled “From Indicators Roadmap for Ship owners and Ports to Incentives and Labs” during the afternoon session of Day 1.
Her intervention brought three key messages to the IMO community:

1. A Mature, Field-Tested Indicator

GME highlighted a 15-year track record, shared across Green Marine and Green Marine Europe, in deploying a URN indicator adopted by over 200 ship owners worldwide, including some 30 in Europe. This provides a unique evidence base on:

• practical mitigation measures,
• fleet-level progress,
• interaction between operational and design-stage improvements.

2. A Roadmap to Align Incentives, Requirements and Capacity-Building

GME emphasised how a structured benchmark — grounded in third-party verification and annual public reporting — can help ship owners progress step by step, while enabling:

• ports to design differentiated fees or incentives,
• regulators to better understand the maturity of available solutions,
• researchers to assess performance trends at scale.

3. A Bridge Between Global Ambitions and Regional Action

GME also showcased its involvement in the Pelagos Consortium, coordinated by the Tethys Research Institute and supported by the Prince Albert II of Monaco Foundation. This initiative aims to strengthen URN mitigation in the Mediterranean, especially within the Pelagos Sanctuary, one of the world’s most sensitive cetacean habitats.

GME’s participation demonstrates how certification frameworks can accelerate cooperation between ship owners, ports, NGOs, scientists, and regulating authorities.

Why the Green Marine–Green Marine Europe frameworks are valuable for the IMO

Through its dual North American–European structure, Green Marine and Green Marine Europe provide unique operational insights into the implementation of URN mitigation measures at a fleet scale.
The programs’ methodology - combining tiered performance levels, third-party verification, and public reporting - offers a scalable model aligned with the IMO Experience-Building Phase.

Beyond its long-standing participation in IMO discussions, Green Marine Europe highlighted the broader ecosystem underpinning its URN work. The indicator has been shaped not only by over 15 years of experience across Green Marine and Green Marine Europe, but also by the active involvement of science-based and conservation-focused organisations such as IFAW, a long-time supporter and member of the GME Steering and Advisory Committees. This collaborative governance model strengthens the scientific credibility of the indicator and anchors it in operational realities reported annually through GME’s Performance Report — which, in 2024, showed that 21% of certified ship owners had reached Level 3 or above through concrete technical measures such as propeller optimisation, advanced hull coatings, or adaptive speed management in sensitive areas.

Looking ahead, GME also recalled the strategic alignment between the forthcoming 2026 revision of the URN indicator, the IMO Experience-Building Phase, and its involvement in the Pelagos Consortium — an international partnership working to make the Pelagos Sanctuary a reference model for cross-border marine governance. This convergence of scientific, regulatory and operational efforts reflects a broader ambition shared by several States and institutions to advance towards a “Quiet Ocean” agenda.

Conclusion: Accelerating the Global Effort to Quiet Our Ocean

The IMO workshop underscored a shared conclusion: meaningful URN reduction will only be achieved if scientific knowledge, technological innovation, and regulatory frameworks converge — and if noise mitigation becomes an integral part of ship design, operations, and investment decisions.

By sharing its field-tested experience and indicator methodology, Green Marine Europe reaffirmed its role as a catalyst for evidence-based, collaborative and ambitious action to protect marine life and support the maritime sector’s environmental transition.

Pictures : IMO