Invasive Alien Species

Invasive Alien Species of Iriomote Island (regulated under the Invasive Alien Species Act)

Cane toad

It has been spotted occasionally, but breeding has not been confirmed. We are keeping a close watch on the situation.


Asian tree frog

In 2015, breeding was confirmed in the Uehara and Nakano areas, and a control program for the species ensued. In October 2019, eradication of the populations in the same areas was announced.

Bitter vine (Mikania micrantha

A fast-growing, vigorous plant with the nickname “mile-a-minute.” We are carrying out work to control this species in the Takana and Shirahama areas.

Parrot’s feather 

A fast-growing prolific aquatic plant. Its presence has been confirmed in the Otomi area.

Water lettuce

This has been found in and around the irrigation canal in the Sonai area.

* The transport, sale, transfer, etc. of regulated invasive alien species is prohibited. If you break the rules, you may face criminal charges. If you encounter examples of these species, please contact our center.

What You Can Do

nvasive alien species can be brought onto the island inadvertently along with everyday goods, building materials, or seedlings, or by means of the luggage, clothes, or shoes of visitors. Preventing the entry of these species is important because they are difficult to eradicate once they have established themselves. We ask for your cooperation.

Checklist (when you go to or send things to Iriomote Island)

・ Before going/sending things to the island

Check to see if your package, luggage, any plant pots or other item you are carrying or sending is harboring any unwanted seeds, or plant or animal life.

・ In transit

Check to see if plant seeds are attached to your clothes or shoe soles.

・ After arrival  

Confirm that luggage or package being carried or delivered is free of contaminants.

Initiatives on Iriomote Island

There are various alien species on Iriomote Island. The Environment Ministry conducts monitoring and control activities on animal and plant species, mainly those regulated under the Invasive Alien Species Act.


Invasive alien frog-species monitoring

Invasive alien plant-control activity