• Water hyacinth, soft-shelled turtle, squirrel are some of the “invasive alien species” in the country.
• They thrive in places where there are no natural habitats and outcompete native species. If left unchecked, these species will have a negative impact on our biodiversity.
• According to the National Invasive Species Strategy and Action Plan (2016-2026), many introductions of these species have been made for horticulture, food production, reforestation and recreation purposes.
• These invasions were observed in wetlands, agricultural areas, protected areas, production and protection forests of the country.

Have you seen hyacinths, leaf stalks and purple flowering water plants floating in waterways?

How about the Chinese soft-shelled turtle that appears in central and southern Luzon, or the Finlayson’s squirrel around Metro Manila?

These are some of the invasive alien species found in the Philippines that thrive in places where there are no natural habitats and compete with our native species. If these species are neglected, our biodiversity will be adversely affected.

As defined by the Department of Environment and Natural Resources (DENR), invasive alien species are “species that are intentionally or unintentionally introduced outside their natural habitats where they have the ability to establish, invade, outcompete native species, and occupy a new environment. .”

According to the Convention on Biological Diversity, alien species invasions can occur in different taxonomic groups such as plants, animals, fungi and microorganisms and can affect ecosystems.

Invasive alien species are characterized by “rapid reproduction and growth, high dispersal capacity, phenotypic plasticity (the ability to physiologically adapt to new conditions), and the ability to survive on a variety of food types and a wide range of environmental conditions.”

He added that alien species invasions can occur in native ecosystems disturbed by humans because there is less competition between native species.

According to the National Invasive Species Strategy and Action Plan (2016-2026), many past and current introductions of these species have been made for horticulture, food production, reforestation and recreation.

Invasion of alien species in a country “was the result of the transport of organisms to a new habitat – this could be between islands within a country or between countries; establishment and propagation of alien species in new habitats – whether natural or artificial, such as enclosures, lakes, reforestation areas and gardens; and uncontrolled proliferation [the] initial population is over [a] large area – either by deliberate release or accidental escape.”

These invasions were observed in the country’s wetlands, agricultural areas, protected areas, production and protection forests; however, most reports are only anecdotal and have not been scientifically studied.

Furthermore, there is a very limited understanding of the impact of invasive alien species on the native biota of the Philippines.

Some invasive aliens in the country are Finlayson’s squirrels, Chinese soft-shelled turtles, and water hyacinths.

Finlayson’s chipmunks, scientific name Callosciurus finlaysonii, are rodents native to Southeast Asian countries such as Vietnam, Cambodia, Lao PDR, Myanmar, and Thailand. They are common in Metro Manila, especially in areas with extensive tree vegetation or vegetation.

These squirrels feed on fruits such as banana, lanzon, durian, santol, duhat and mango; vegetables like patola and patani; and young coconut shoots. They have been observed to attack the eggs and chicks of birds, destroy their properties, and are associated with pathogenic microorganisms that can affect human and animal health.

Scientifically known as Pelodiscus sinensis, Chinese soft-shelled turtles have been found in the country’s special wetlands and other areas, including areas used for aquaculture. They have a large population in Pampanga and are likely to grow in Bulacan, Laguna, Mindoro, Nueva Ecija and Rizal.

Overpopulation of these turtles potentially endangers endemic and native fish in the country, including local fishponds and fishing operations.

Water hyacinths, or Eichhornia crassipes, are floating aquatic plants native to tropical South America. They were introduced in the country as ornamental plants, but over the years they have become a problem for the country.

Some of their effects include obstructing waterways, limiting boating, navigation and recreational activities, severely damaging fish nests and cages, and preventing sunlight and oxygen from reaching the water column and underwater plants.

DENR Sec. Maria Antonia Yulo-Loyzaga, Secretary of the Department of Environment and Natural Resources, recently urged lawmakers to include invasive alien species and other threats to biodiversity in strengthening the Wildlife Resources Conservation and Conservation Act, or Republic Act No. 9147.

“It is time to address threats to biodiversity such as the proliferation of invasive alien species, habitat destruction, unsustainable resource use, illegal wildlife trade and environmental pollution,” Loyzaga said.

In July 2022, Senate Bill 125, introduced by Senator Cynthia Villar, amended the 21-year-old law to include invasive alien species control and management mechanisms.