Weeds and Pests

Infestation by water hyacinth is causing problems in wetlands on Vella Lavella and Choiseul Islands.
© WWF Solomon Islands / Peter Soleness

The problems caused by introduced weeds and feral animals are becoming more widespread in Solomon Islands.

• Weed infestation in forests: There are already large infestations of 'Mile a Minute' or 'Morning Glory', particularly on Makira where large tracts of coastal rainforest are being smothered by this vigorous vine.
• Weed infestation in river systems: Water hyacinth has invaded river systems on Vella Lavella and Choiseul.
• Cats: Feral and domestic cats have had considerable impact on populations of megapodes (Megapodius eremita) on Simbo Island. The resource owners are now practising cat culls in order to manage the problem. Elsewhere, populations of birds, small animals and reptiles are threatened by the predatory behaviour of cats.
  
• Cane toads: Cane toads were introduced into Solomon Islands in the middle of the last century. They are now distributed widely throughout lowland areas, and have devastated populations of indigenous frogs.
• Introduced marine organisms: Currently, there is little control exerted over the discharge of bilge water and ballast from trading and fishing vessels into Solomon Islands seas. There has been considerable research undertaken overseas on the ecological problems caused by this practice, but its impact is poorly understood in Solomon Islands. Water discharge from ships may introduce exotic organisms that have no natural predators in the new habitat, allowing them to compete successfully against native species.