A FRAMEWORK FOR CONTROLLING UNINTENTIONAL INTRODUCTIONS OF INVASIVE ALIEN SPECIES IN SINGAPORE

Abstract

Invasive Alien Species (IAS) are often considered the second biggest factor threatening biodiversity globally, after habitat loss and destruction. The threat of IAS works synergistically with multiple direct drivers of ecosystem change such as habitat loss and climate change, placing increasing pressure on species, particularly in fragile ecosystems such as freshwater systems. Introductions of IAS can broadly be categorised as unintentional (incidental) and intentional (deliberate), depending on how they were introduced. While intentional introductions can largely be controlled through effective regulations (such as the banning of certain ornamental plants or aquarium fish in a country) and enforcement, the prevention and control of unintentional introductions is often more complex due to the unpredictability of the pathways in which they are introduced and challenges in monitoring and detection. In this dissertation, I develop a management framework for controlling the unintentional introduction of IAS in Singapore. I first review literature on the pathways (i.e., sources) of unintentional introductions of IAS globally and the known impacts of such introductions on biodiversity, human health, and economy. I provide an overview of unintentionally introduced IAS in Singapore, including several case studies and the existing measures for dealing with unintentional IAS in Singapore, and identify the gaps in current measures for dealing with IAS in Singapore. I then conduct a global review of current methods of controlling IAS at different stages (introduction, establishment, proliferation, and impact) of the invasion process; using this information, I formulate recommendations to address the identified gaps in policy and practical approaches towards the control of unintentionally introduced IAS introductions in Singapore.