Otters were once heavily hunted for their fur, many to the point of near extinction. While their numbers have slowly recovered, many species still stand below their historical population numbers.
Pollution and global warming, and rising pet trade are huge threats to the adorable species.
Otters belong to the Mustelidae family, which includes other carnivorous mammals such as weasels, skunks, minks, and badgers.
There are currently 13 species of otters spreading across Asia, Africa, Europe, South and North America.
These include the smooth-coated otters that have been roaming freely in Singapore since the 1990s. The mammals have been spotted in places like Sungei Buloh, Bishan-Ang Mo Kio Park and Gardens by the Bay.
While most otter species live in freshwater rivers, lakes, and wetlands, the sea otters and the smaller marine otters are found in the Pacific Ocean.
Sea otters were hunted to near extinction during the fur trade in the 18th and 19th century. Their population numbers have somewhat recovered, following conservation efforts such as the signing of the International Fur Seal Treaty of 1911. They received additional safeguards in the 1970s under the Marine Mammal Protection Act and the Endangered Species.
However, sea otters are still listed as endangered on the International Union for Conservation of Nature (IUCN) Red List. Four other otter species are also listed on the list as endangered, including the giant otter, marine otter, hairy-nosed otter, and southern river otter.
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The smooth-coated otters and the Asian small-clawed otters – typically found in Singapore on offshore islands such as Pulau Ubin and Pulau Tekong – are listed as vulnerable with decreasing population numbers.
Both species’ numbers in the wild have fallen by at least 30 per cent in the past 30 years, according to conservationists.
The Japanese river otter, a subspecies of the Eurasian otter, was officially declared extinct in 2012.
Otterly cool facts
Small animal, big appetite
Otters eat about 25 per cent of their body weight every day in order to stay warm and survive.
Smooth-coated otters are not known to be picky about their food, and will catch fish wherever they can, from the canals of the Singapore mainland to the koi ponds on the offshore neighbourhood of Sentosa Cove. And just so you know, even the arowanas are not safe.
Fast learners in an urban environment
While smooth-coated otters may not be as prolific in using tools as their sea otter cousins, they’ve picked up a fair bit living in a city like Singapore. These otters have learnt to use stairs and ladders to access the canals, which often have vertical concrete walls, as they navigate the urban landscape!
Smooth-coated otters often "juggle" with stones – and scientists say they do so because when they are hungry.
Under the sea
Otters have highly buoyant bodies due to their large lung capacities, which are about 2.5 times bigger than that of similar-sized land mammals. They can hold their breath underwater for over five minutes at one time – river otters can hold theirs for up to eight minutes!
Communicating with dung
Otters’ dung has its own name: spraint. The scents can vary, with some scientists describing them smelling like violet flower or jasmine tea.
They use their dung as a tool for communication, and sometimes dance after discharging it. A sniff of the dung by other otters can provide pertinent information, such as their sex, reproductive and dominance status, and diet.
These rambunctious and gregarious mammals tend to chat a lot. They have several distinct noises, including a “Hah!” shout to alert that a threat is nearby.
Otters at risk
Otters, as keystone predators, are critical to maintaining the balance of nearshore ecosystems.
Without the sea otters, for instance, an overpopulation of sea urchins can lead to the decimation of kelp forests, which provides cover and food for many other marine animals.
However, these mammals remain at risk from threats such as pollution, habitat loss from reclamation projects, and the lucrative pet trade, even with regulations put in place to protect them.
Habitat loss & pollution
Human activities such as the reclamation of peat swamp forests and mangroves as well as the construction of large-scale hydroelectric projects have directly impacted the population of the smooth-coated otters.
Water courses being polluted by pesticides from plantations reduces the quality of the habitats as well as the otters’ prey base.
Smooth-coated otters threaten the income of fishermen as they eat fish from commercial fishing zones. As such, fishermen as well as aquaculturists may cull the animals to get rid of their “competitors”.
Furthermore, otters also frequently become trapped in fishing nets, causing them to drown.
Even in Singapore, the country’s otter population became a subject of debate during the coronavirus lockdown, with the creatures encroaching on human habitats and sparking backlash.
Keeping otters as pets have been made popular in countries like Japan, where videos of their “adorable” antics are very popular on social media. The market for these poached animals is booming in Southeast Asia, where researchers believe people are stealing them from the wild to sell as pets.
According to a June 2018 Traffic report, at least 700 otters were being advertised for sale on Facebook in Indonesia, Thailand, Vietnam and Malaysia over a four-month period in the same year.
Parts of the otters, including their bones and blood, are incorporated in traditional medicines despite having no scientific basis.
For instance, in India, otter blood is used to treat epilepsy and oil extracted from their fat is used to treat joint pains and pneumonia. In Cambodia, a mixture comprising an otter’s penis bone and coconut milk has been prescribed as an aphrodisiac.