Folder Invasive Species in Palau

Monkeys, cockatoos, smothering vines, snails, aggressive fish, bottom-dwelling marine organisms, agricultural pests, and human disease-causing microorganisms:  all of these and more have invaded Palau, and all are having impacts on the environment, the economy, human health, and even the traditional Palauan way of life.  

 

What are invasive species?

Invasive species are living organisms, which, for various reasons, begin to grow and reproduce out of control and cause harm to other living things around them.  In some cases, invasive species have caused major alterations in ecosystems, and even extinctions of other species of living things.  In most cases, invasive species become invasive when they are introduced into a new environment where they have no natural enemies.  These are often referred to as Invasive Alien Species (IAS).

 

 

In some cases, a naturally occurring species can become invasive when conditions change.  A good example of this is the plant known in Palau as kebeas (Merremia peltata).  Kebeas is a very vigorous and fast-growing vine that naturally grows in forest clearings.  As little as twenty years ago, kebeas was common, but not generally a  problem in Palau.  Now, land clearing, road construction, and other human activities have created more opportunities for kebeas to thrive.  At the same time, there are fewer human activities to control its growth, which is now threatening forests and communities on the islands of Koror and Babeldaob. 

 

Threats

Invasive Alien Species are one of the greatest threats to biological diversity worldwide, and in islands they are often the number one threat to biodiversity.  Invasive species cause harm by:

  • Eating animals or their eggs (monkeys, for example, eat bird eggs and nestlings),
  • Eating plants (parrots and cockatoos eat the hearts of two palm trees found only in Palau's rock islands, killing the trees),
  • Growing over plants (several invasive vines), 
  • Increasing the likelihood of wildfires (several plants, most notably cogon grass - Imperata cylindrica and Chromolaena odorata),  
  • Being more likely to survive fires (same as the above, plus African Tulip tree - Spathodea campanulata), 
  • Carrying diseases (city pigeon, rats, mosquitoes),
  • Causing diseases of humans, animals, and plants (micro-organisms),
  • Making noise (coqui tree frog, cockatoo, and parrot), and
  • Many others. 

Means of Introduction

Many living things have adaptations which help them to move from place to place naturally.  Most biological invasions, however, are the result of human activities.  Humans move, or introduce, living things like ornamental and crop plants, and pet and livestock animals from one place to another intentionally.  Many introductions are unintentional; ants, plant seeds, disease organisms, snail eggs, and many others can be hidden in cargo, attach to clothing, and find other ways to move in the things that people transport. 

 

Example 1:  The brown tree snake, which has devastated the bird populations of Guam and which costs Guam's economy millions of US dollars every year, is notorious for its ability to hide in very small places.  Every car, box, refrigerator, and other items imported to Palau from Guam are and must continue to be thoroughly inspected to ensure that brown tree snake do not enter our islands. 

 

Example 2:  Another example is the coqui, a tiny frog with a very loud voice.  Hawai'i's tourism industry is now suffering because the loud call of the coqui disturbs the peace and quiet that many tourists are seeking.  The coqui lays its eggs on vegetation, so every plant imported into Palau from Hawai'i, including cut flowers and nursery stock, must be thoroughly inspected for the tiny coqui eggs.

Seeds of invasive weeds can be caught in radiators and other crevices of automobiles, trucks, and heavy equipment.  Any previously used mechanical equipment must be thoroughly cleaned prior to entry into Palau.  Steam cleaning does not offer a complete guarantee that no seeds will survive.  Weed seeds are very hardy and can even survive being eaten by livestock.  Therefore, any transboundary movement of livestock must require that the animal be fed only weed-free feed for several days prior to importation.

 

Prevention 

How can Palau deal with these invasions? Can some of the invaders be eradicated?  If not, what actions can be taken to minimize their impacts?  Howe can future invasions be prevented?  There are numerous plants, animals, and other organisms causing problems in other Pacific Islands that has yet to be found in Palau.  How can Palau keep them out? 

In order to prevent and manage biological invasions:

  • We need to know what Palau's current invasive species situation is
  • We need to have the ability to detect and rapidly respond to invasions 

As Palau continues to develop, land and coral reefs and associated habitats will come under increasing threat of environmental degradation.  The construction of a 53-mile circumferential road and the relocation of the national capitol to Palau's largest island, Babeldaob, are expected to bring large-scale development to the big island.   The increasing pace and scope of development in Palau makes this a critical time for effective measures to conserve Palau's unique environment.

Increased international travel and trade have made Palau more susceptible to introductions of invasive species.  In addition, increased internal movement of people and goods makes the internal spread of invasive species from island to island more likely.  Measures are being undertaken to prevent both of these concerns, but more remains to be done.     

The best method to prevent the introduction of many invasive species is through a regional cooperative approach.  Palau is and will continue to work closely with its Pacific island neighbors to reduce the potential of invasive species introductions within its boarders.  Palau is also an active participant in the larger international initiatives, such as the Global Invasive Species Programme, the UN Convention on Biological Diversity, the Cooperative Islands Initiative for Invasive Species, among others.  

For more information on Palau's initiatives for the management of invasive species, invasive species FACT SHEETS and PALAU FORESTRY 2008 CALENDAR, please visit our Reports section of this website.