Invasive species in Singapore

Plants, animals and microorganisms within a particular ecosystem can become invasive when introduced to new areas and negatively impact its biodiversity. Their spread involves 4 stages: introduction, establishment, invasion and spread.

There are 2 ways invasive species can be introduced:

Type of introduction	Examples
Unintentional introduction: This happens when humans or their activities accidentally spread these species beyond their natural range.	Ballast water releases from ships, hull fouling Organisms in or on timber or wood products, packing materials and in shipping containers or cargo In or on various modes of transportation like cars, trucks, boats, aeroplanes, ships, etc Organisms in imported nursery soils Organisms in imported fruits and vegetables Tourists and their luggage or equipment
Intentional introduction: This occurs when humans deliberately move a species beyond its natural range and dispersal potential.	Release of unwanted pets and aquarium animals into the wild Plants introduced for gardens and landscaping Biological control of pests or other invasive populations

Invasive species are known as one of the main threats to biodiversity loss. They can cause negative impacts at the species, population and community levels, and the most significant harm is altering ecosystem functions.

These include:

Threatening the survival of native plants and animals by competing for resources.
Altering vegetation structures and community composition, which in turn upset the ecosystem's balance.
Incurring significant costs and resources if their population is not controlled properly.
Endangering human health if organisms harbour foreign pests and diseases.
Hybridising with native species, resulting in negative genetic impacts.

Common invasive species in Singapore

Examples of invasive species which are thriving in Singapore and pose a threat to our native flora and fauna include:

Plant species

Zanzibar Yam

If left unchecked, this fast-growing climber spirals up trees and completely smothers the canopy with its bat-like foliage.

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Hairy Clidemia

Its ability to rapidly spread and form dense thickets is the primary reason for its invasive status.

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Mile-A-Minute Weed

This climber grows incredibly fast, forming dense mats that smother native plants.

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Animal species

American Bullfrog

This amphibian is a voracious carnivore that consumes anything that can fit in its mouth.

Javan Myna

It has become one of Singapore's most abundant birds and consumes a wide variety of food ranging from food scraps to small reptiles and insects.

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White-crested Laughingthrush

This bird's relatively larger size and omnivorous diet allows it to compete aggressively for a wide range of resources.

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Variable Squirrel

This species is known to strip bark from trees, adversely affecting their health, particularly younger saplings.

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Measures to control invasive species in Singapore

Refer to the following to find out how we are dealing with invasive alien species in Singapore.

The use of legislation is an important component in alien species management. Laws strictly control the introduction and spread of non-native species in Singapore.

We work with other government agencies to enforce the following regulations in order to protect our ecosystems:

Individuals and school groups can volunteer for the ISM to support our ongoing management efforts.

Find out more about ISMs.

One way to prevent the introduction of alien species is through public education about the impact releasing alien species into our ecosystem will bring.

About Operation No Release

“Operation No Release” is a programme discouraging the “mercy” release of animals or unwanted pets into parks and nature reserves. This programme came about in response to members of the public releasing animals (often into the Central Catchment Nature Reserve) to gain merit, especially during the annual Vesak Day.

This harmful practice upsets the ecosystem and endangers local biodiversity, especially if it involves the release of invasive species such as the red-eared slider, which can be easily bought from the local aquarium shops or markets.

We partnered with the then-AVA, Public Utilities Board (PUB), Nature Society (Singapore), students from various schools and volunteer groups, to educate the public about the dangers of releasing animals. This included:

Pre-Vesak Day activities such as conducting educational talks, exhibitions and distributing brochures.
On-site interventions by NParks rangers and volunteers at popular release locations around the CCNR on Vesak Day.

Since the programme was introduced, there has been a noticeable decrease in the number of animal releases.

What you can do

Refer to the following for tips on controlling the spread of alien species

Avoid buying or growing plants known to be invasive.
Avoid planting exotic garden shrubs but if you do so, avoid planting them next to, or within nature reserves and natural areas.
Use native plants to landscape your garden.

Native plants can usually be grown without risk and may provide food, cover or nesting sites for birds and butterflies.

Learn which plants are invasive and remove them from your garden.

Replace them with native plants where possible.

Do not dump unwanted plants in a nearby park or natural area.
- Invasive plants can spread very easily from plant fragments, seeds and berries.

Ensure your non-native pets are legally imported by buying from reputable dealers.

Look for clear labelling and check your pet does not harbour any foreign pests or diseases that can spread to native wildlife.

Do not release aquarium fish into ponds, reservoirs, or natural streams.

If you do not want your pet fish, return it to a local pet shop for resale, give it to another hobbyist or donate it to a school.

Do not release other pets into the wild.

Pet amphibians and reptiles may prey on a wide variety of native species and may carry diseases.
Most domesticated pets such as rabbits and hamsters cannot survive when released into the wild and may carry diseases.

Avoid carrying seeds, live plants, fruit, vegetables, soil, insects, lizards, snails, or other animals into or out of the country.
Follow local and international quarantine measures to prevent the spread of serious insect pests, weeds and diseases.

Invasive species in Singapore