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| Dugong feeding trails on Cyrene opposite Pasir Panjang Container Terminals, May 2025 |
This complements a separate project by NUS researchers that monitored the vocalisations of marine mammals between 2019 and 2022. Funded by NParks, the acoustic project highlighted that both Sisters’ Islands and Kusu Island recorded the highest number of vocal detections of dolphins, "playing a key factor in safeguarding this location as the second marine park,” said Dr Dr Karenne Tun.
She did not mention when the advisory will be ready.
NParks drawing up advisory on how to shield marine mammals from coastal development noise
Ang Qing Straits Times Jan 12, 2026
SINGAPORE – Developers undertaking marine works in Singapore waters will get guidelines designed to reduce underwater noise, in a move to protect the Republic’s elusive marine mammals.
The National Parks Board (NParks) is drawing up an advisory that informs developers on ways to avoid harming creatures such as the Indo-Pacific humpback dolphin and the dugong that frequent Singapore’s coastal waters, The Straits Times has learnt.
This comes as more coastal development projects are in the pipeline as Singapore combats rising sea levels and reclaims more land. In the coming decades, for instance, it is planning to reclaim about 800ha of land off East Coast Park to develop Long Island.
Industry consultants said the advisory will ensure that underwater noise here is dealt with systematically, instead of leaving its management to the discretion of developers.
Underwater noise is an invisible but potent stressor for marine mammals, which rely heavily on sounds like clicks and trills to communicate and navigate. Man-made noise can mask these signals, cause severe stress and impair the hearing of these creatures.
Due to the vast ocean habitat of marine mammals, it is difficult to track the implications of underwater noise pollution. However, studies show that sonar use has altered the feeding behaviour of blue whales and stranded others on beaches.
Dr Karenne Tun, group director of NParks’ National Biodiversity Centre, told ST that the measures could advise developers to gradually ramp up the intensity of marine piling works – a noisy process that involves driving piles deep into the seabed – while ensuring that no marine mammals are in sight.
This “soft start” approach gives marine mammals a crucial window of time to flee the area before noise levels increase further.
She did not mention when the advisory will be ready.
The development of the advisory follows a recent study by researchers from the National University of Singapore (NUS) who compiled all reliable records of marine mammals in Singapore’s territorial waters from 1820 to 2024 to identify their hot spots.
Mr Sirius Ng, the paper’s lead author, noted that the research was initiated to establish a baseline for Singapore’s wild marine mammals.
“Because of the paucity of this data, policies protecting marine mammals tend to focus on the general marine environment, rather than being ecologically tailored for the species themselves,” he said.
The study found that Indo-Pacific humpback dolphins and Indo-Pacific bottlenose dolphins were mainly observed within the Southern Islands. The average sizes of their pods also declined, a trend that appeared most evidently over the past three decades.
Dugongs were most commonly spotted at the Sungei Johor Estuary, notably Changi, Pasir Ris and Pulau Ubin, where two international shipping channels meet.
Surprisingly, the paper found that over time, Indo-Pacific humpback dolphins tended to appear in areas closer to urban areas with higher vessel activity, adapting to human activities in ways that are still not fully understood.
Dr Tun said NParks plans to study these important findings, which complement a separate project by NUS researchers that monitored the vocalisations of marine mammals between 2019 and 2022.
That project, funded by NParks, sought to understand the distribution of marine mammals in Singapore’s coastal waters as well as guide development activities in the waters.
“In particular, results from (the acoustic project) highlighted that waters off both Sisters’ Islands and Kusu Island recorded the highest number of vocal detections of dolphins in the southern waters of Singapore, playing a key factor in safeguarding this location as the second marine park,” said Dr Tun.
Singapore announced its first marine park to conserve the biodiversity at Sisters’ Islands in 2014, and revealed in 2024 plans for a second one at the southern part of Lazarus Island and the reef off Kusu Island.
Dr Tun said the acoustic research project emphasised the need to account for the impact of sound in the planning and staging of marine works.
Industry consultants said the advisory will also help Singapore develop its environment responsibly while avoiding delays and reputational concerns arising from negative acoustic impact on fauna.
Ms Holly Siow, head of ecology at environmental consultancy DHI Water & Environment, said the advisory will give “much-needed clarity and consistency for developers”, elevating acoustic impact to a core component of marine development planning.
“From a developer’s perspective, this also reduces regulatory and project risk,” she added.
“When expectations around acoustic mitigation are clearly articulated upfront, developers can factor them into project design and scheduling early on, rather than responding to issues later during approval or construction.”
Singapore’s coastal waters are rich in marine biodiversity, and ensuring mitigation is targeted where it matters most is essential to balancing development with conservation, she said.
Ms Siow called on NParks to consider embedding noise-related standard operating procedures into tender specifications for environmental impact assessments, as well as environmental monitoring and management plans.
Mr Lee Adam Harryman, head of the Climate Resilience Studio at CPG Consultants, said the advisory “should lead to better coordinated projects, fewer late changes and closer alignment between environmental safeguards and engineering delivery”.
He noted that “measures to manage underwater noise are commonly built into project approval processes at the government level” in some countries abroad.
He added that Singapore’s approach is encouraging because it is “grounded in local, science-based research”.
“This ensures the measures are tailored to Singapore’s waters and marine species, rather than simply adopting overseas standards.”
NParks’ move to draw up an advisory is consistent with practices in jurisdictions with established marine construction activity, such as Australia, Britain, Canada and the United States, where more sophisticated guidelines are already in place, the consultants said.
In Europe, standard measures include deploying marine mammal observers for high-risk activities, and bubble curtains – technology that uses veils of air bubbles to dampen sound waves, according to Ms Siow.
As the Republic looks to the future, the integration of acoustic monitoring can play a key role in long-term coastal management, said NUS researchers Hari Vishnu and Koay Teong Beng, who had worked on the acoustic monitoring project.
“Acoustics can especially play an important part in assessing the effects of anthropogenic events such as oil spills, or development projects around Singapore’s waters,” said Dr Vishnu, citing the technology’s ability to monitor at scale.
Mr Koay noted that while their initial study covered the majority of expected biodiversity hot spots, it did not cover the entire Singapore coastline.
They said: “Our study was done over a period of 2.5 years, so it would make sense to extend this to more continuous and longer-term monitoring so that our observations are not just limited to this period.”