Delphine Estibeiro –
An emerging environmental issue that remains unfamiliar to much of the maritime industry took centre stage at INMARCO 2026 on 28th October in Mumbai, as Capt Nalin Pandey and Capt Samir Kumar presented a technical briefing on Underwater Radiated Noise (URN) and the proposed Framework for Integrated Shipboard Harmonics Control (FISH) before a packed audience of national and international delegates.
Hosted at the Westin Powai, the session highlighted what many experts increasingly regard as the next major environmental challenge for shipping after emissions. The presentation explored how continuous low-frequency sound generated by commercial vessels, primarily through propeller cavitation, machinery vibration and hull movement, can travel vast distances underwater and interfere with marine ecosystems.
A key reference during the presentation was the March 2000 Bahamas mass stranding event, where 17 beaked and minke whales were found stranded with injuries linked to intense underwater acoustic activity. The incident is widely regarded as one of the earliest warning signs of the potential biological impacts of underwater noise.
The speakers traced the evolution of the issue at the International Maritime Organization (IMO), where underwater noise was first raised in 2004. Revised voluntary guidelines were approved in 2023, while a formal URN Action Plan and experience-building phase were launched in 2024. International discussions are expected to continue over the coming years as regulators gather operational data and assess mitigation measures.
For many delegates, the topic was entirely new. Participants expressed keen interest in understanding how underwater noise affects marine mammals, fish populations and broader ocean biodiversity through disruption of communication, navigation and feeding patterns. The presentation emphasized that marine species rely heavily on sound for survival, making excessive underwater noise a growing ecological concern.
The FISH framework proposed by the presenters advocates a structured approach centred on fleet design optimisation, implementation of IMO guidance, sound monitoring and habitat protection measures. Recommended actions include quieter ship designs, improved propellers, noise monitoring systems, route planning and speed management in sensitive marine areas.
The speakers also noted the importance of India proactively examining regulatory and operational measures to safeguard its underwater marine assets, particularly around the Lakshadweep Islands, Andaman & Nicobar Islands and the country’s vast Exclusive Economic Zone (EEZ).
Concluding the session, Capt Pandey acknowledged the contributions of the team behind the initiative and thanked delegates, industry stakeholders and members of the maritime press for their participation.
The overwhelming response suggested that while URN may still be in the early stages of global policy development, awareness within the maritime community is growing rapidly. As the industry pursues decarbonisation and sustainability goals, the challenge of reducing underwater noise may soon become an integral part of responsible shipping.
Marex Media