Otter-ly Cute: The Success of Otters in the Urban Waterways of Singapore

Singapore’s waterways have seen a massive transformation over the past few decades. From being highly polluted, filled with trash and sewage as the Singapore River was in the late 1970s, Singapore’s waters have never been cleaner after the launch of the Clean River Campaign in 1977 (Xu, 2019). Since then, ecological conditions have improved, making urban waterways habitable  for otters, semi-aquatic mammals that have well-adapted to Singapore’s urban environment. Today, as many as 70 otters can be found in Singapore, thriving in the canals and rivers that link the country’s various water bodies, and are often sighted much to the surprise of members of the public (Turrell, 2020). In fact, these charismatic mammals have gained much popularity among local followers and even attracted fans across the globe (Ishak, 2020)!

An illustration showing the differences between the smooth-coated and Asian small-clawed otters that are commonly seen in Singapore.

The two main species of otters that can be found in Singapore (Xu, 2019)

So how did these otters get here and settle in Singapore’s urban environment? Were they originally in Singapore or did they immigrate from elsewhere? 

Historically, otters used to be found in Singapore in the 1960s. However, due to habitat disruption and water pollution from land reclamation and urban development, otter populations declined and eventually disappeared sometime between 1970 to 1980 (Sivasothi & Nor, 1994). As water quality improved after 1977, otters began to return to the waterways of Singapore possibly when a population swam across the Johor Straits from Malaysia to the North side of Singapore. Thereafter, sightings have been noted in Sungei Buloh Wetland Nature Reserve, Ang Mo Kio (AMK)-Bishan Park and even Marina Bay (Xu, 2019)!

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Otters spotted along a path in Marina Bay (Photo credits: Bernard “Ottergrapher” Seah)

Why are otters so successful in Singapore’s urban environment?

There are three main reasons why otters have been able to adapt and establish populations successfully in Singapore.

  1. Otters mainly eat fish (piscivorous), but they are also able to accommodate a wide diet which includes prawns, crabs and even amphibians (Theng et al., 2016). As urban waterways are abundant with fish, particular exotic fish species such as Tilapia, they have been able to support the local otter populations that we see today (AMK-Bishan population, Marina Bay population, etc). In addition, most of the waterways in Singapore are connected, allowing otters to swim from one place to another in search for more food!
  2. Otters are semi-aquatic and thus they require dry land for grooming (rolling on grass/sand/soil), resting, sleeping and even seeking refuge from disturbances in vegetation (Theng & Sivasothi, 2016). As such, riparian zones are highly important for the survival of otters. Since the landscape of most urban waterways are gently sloping, such as that of AMK-Bishan Park and Marina Bay, as opposed to being vertical concrete walls, they allow for otters to access land from the waterways easily. Additionally, otters have been noted to exploit urban sites such as canals as holts (resting sites), which are normally holes dug in the ground by otters in the wild (Turrell, 2020). This level of adaptability to utilise urban structures and waterways has therefore enabled them to be successful in Singapore.
  3. Lastly, there are no natural predators in urban waterways that threaten their survival such as wild/stray dogs. Otters are hence the apex predators in urban waterway habitats (Theng et al., 2016). Plus, humans love otters – who would want to remove them from our waterways? (Except for several occasions when otters sneaked into a residential area and devoured $80,000 worth of koi fish, but that is another topic for discussion in itself. More about it here)

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A young otter pup with its catch of the day: a crayfish (Photo credits:  Bernard “Ottergrapher” Seah)

As such, these are the reasons why otters are able to make a comeback in Singapore and adapt to the country’s urban waterways so well. Otter populations have been doing so well that recently, the AMK-Bishan family has clashed with the Marina Bay family in Kallang Basin to expand their territory! (video of their ‘violent’ gang fight below)

Hopefully, the otter population will continue to grow bigger in future and bring more joy to Singaporeans as humans and otters co-exist together.





Ishak, N. S. (2019, January 14). Singapore otters a hit overseas. Retrieved on 18 April 2020, from:

Sivasothi, N. & B. H. M. Nor (1994). A review of otters (Carnivora: Mustelidae: Lutrinae) in Malaysia and Singapore. Hydrobiologia, 285: 151-170.

Theng, M. & N., Sivasothi & Tan, H. (2016). Diet of the smooth-coated otter Lutrogale perspicillata (Geoffroy, 1826) at natural and modified sites in Singapore. The Raffles Bulletin of Zoology. 64. 290-301.

Theng, M. & N., Sivasothi (2016). The Smooth-Coated Otter Lutrogale perspicillata (Mammalia: Mustelidae) in Singapore: Establishment and Expansion in Natural and Semi-Urban Environments. IUCN/SCC Otter Specialist Group Bulletin. 33. 37-49.

Turrell, C. (2020, March 10). Cheeky otters are thriving in Singapore-and adapting quickly to big city life. Retrieved on 18 April 2020, from:

Xu, K. (2019, March 8). The otter side of Singapore. Retrieved on 18 April 2020, from:

Nature Deficit Disorder in the time of COVID-19

In the midst of the COVID-19 pandemic, Singapore has issued a ‘circuit breaker’ where Singaporeans have been advised to stay home as much as possible. Non-essential workers have to work from home, and schools are carrying out home-based learning. Only essential activities like going to get groceries, or getting packed food are allowed. Shopping malls, gymnasiums, and swimming pools are also closed, leaving the only option for Singaporeans’ leisure to be parks.

Singapore, being a 100% urbanised city, has a population that suffers from Nature Deficit Disorder (NDD). Although NDD is not an official medical diagnosis, it is an explanation for erratic behaviours, moods, and poor health, in an individual due to the lack of time spent in nature or outdoors.

With the implementation of the ‘circuit breaker’, people are being forced to spend time outdoors and in parks for leisure since they are the only places of leisure that still remain accessible. Studies have shown that by spending more time in nature, one should see an improvement in their health and mood. Does this mean that once we come out of this pandemic and ‘circuit breaker’, Singaporeans will be a healthier and happier group of people? It’s possible.

On the other hand, some people do not have the privilege of spending time outside. Since everything is now based at home, it blurs the line between work and rest, resulting in work being more demanding. For essential workers (healthcare workers, supermarket retail assistants, delivery riders, etc.), they would be required to be at their jobs which are now asking even more from them. Along with the high levels of stress at work coupled with the lack of time available to spend in nature, would this further exacerbate the effects of NDD? It’s possible.

Therefore, this is something for all of us to consider. The Singaporean habit which leaves us detached from nature is concerning when it comes to NDD. However, will the ‘circuit breaker’ caused by COVID-19 be able to alleviate the problems of NDD that is widespread in a highly urbanised city like Singapore? Or will it exacerbate the problem instead?


Ministry of Health Singapore. (2020, April 3). Circuit Breaker to Minimise Further Spread of COVID-19 [Press release]. Retrieved April, 2020, from

Louv, R. (2013). Last Child in the Woods: Saving our Children from Nature-Deficit Disorder. London: Atlantic Books.

University of East Anglia, UEA Norwich Medical School. (2018, July 6). It’s official – spending time outside is good for you [Press release]. Retrieved April, 2020, from

Zero-Energy Buildings

Concrete buildings frame our urban landscape backdrop in view of limited land space in Singapore. Buildings are everywhere to feed our industrialisation needs. Therefore, the development of sustainable buildings is prudent in achieving our environmental goals of curbing rising greenhouse gases emission. 1980s saw the birth of low-energy buildings which are buildings that uses less energy than a standard building that house the same amenities. In recent years, we witness a new wave of energy efficient buildings entering the picture – Zero-Energy buildings. Zero-Energy buildings produces as much renewable energy as it needs and is not connected to the nation’s electricity grid (Wall, 2017). It has myriad of benefits including reduction in carbon dioxide emission, being energy saving and contributing to environmental protection (Deng et al., 2014).

The design is guided by 5 basic principles of Green Building:

  • Sustainable Site Design
  • Water Conservation and Quality
  • Energy and Environment
  • Conservation of resources and reuse of materials
  • Indoor Environmental Quality

Zero-Energy building reached Singapore’s shore in 2009. As part of Building and Construction Authority’s (BCA) Green Building Masterplan, an existing building within BCA Academy was revamped into a Zero-Energy Building. It is fully powered by three generations of photovoltaic systems that harnesses energy from the sun. Key features of the building include 40% reduction in energy required to run air-conditioning through usage of advanced chillers and personalised ventilation system and strategically places shading devices that reduces solar heat gain and improve quality of natural lighting with the building. It is a pilot project that serves as a test-bedding centre for Green Building Technologies. As BCA oversees Singapore’s Green Mark buildings rating system, they wanted the project to reflect best sustainable building practices. Five years later, net zero energy targets have been attained and occupants are reaping the benefits of increased thermal comfort (Wittkopf, 2015).

Right at the heart of NUS, we welcome our nation’s first Zero-Energy building built from scratch in 2019 – School of Design and Environment 4. The building house more than 1200 photovoltaic solar panels that is involved in generating 500 megawatts of energy a year, slightly more than the expected usage of the building. This will allow the building to potentially save up to $180000 in electricity cost. Along with its unique architecture design, this made SDE4 a sustainable building design, an important attribute of green buildings. NUS is also committed to reducing energy demand by 40-60% as buildings accounts for 40% of greenhouse gas emission worldwide (Toh, 2019). Key features of the building include an innovative hybrid cooling system to supply rooms with cooler air during times of higher temperature and humidity as compared to conventional cooling system while ensuring that rooms would not be too cold. Ceiling fans speed are also adjusted to decrease usage of air-conditioning which accounts for up to 60% of a tropical country building’s total energy usage. Such energy saving and resources conservation certainly meets the basic principles of green buildings.

In fact, SDE4 was an idea birthed 10 years ago but was rejected then due to overall cost required. Therefore, it is extremely heartening to be living in this generation where the community is committed to see beyond initial financial burden to do their part for the environment. Inter-Ministerial Committee on Sustainable Development has also set a target to achieve 80% Green Mark Certification for all buildings by 2030. With SDE4 and BCA Academy setting stones for Zero-Energy buildings in Singapore, I believe we will be able to look forward to more of such project in our island home.


Deng, S., Wang, R. Z., & Dai, Y. J. (2014). How to evaluate performance of net zero energy building – A literature research. In Energy (Vol. 71, pp. 1–16). Elsevier Ltd.

Toh, M. (2019, April 2). Zero energy building opens in Singapore – CNN. CNN Business.

Wall, M. (2017). Towards zero-energy buildings and neighbourhoods – A combination of energy-efficiency and local renewable energy production. Indoor and Built Environment, 26(10), 1313–1318.

Wittkopf, S. (2015). Zero Energy Building @ BCA Academy: Singapore.