Economic impact of IAS in the Caribbean: case studies.
Invasive Alien Species (IAS) have a negative impact on crop and pasture production, human and animal health, biodiversity and a multitude of other goods and services provided by ecosystems and as such pose one of the biggest threats to economic development on this planet. In fact, it was estimated in 2001 that the impact and cost of managing IAS globally accounted for US$1.4 trillion annually or 5% of annual global GDP (Pimentel et al., 2001). Many of these costs, especially losses to biodiversity are difficult to quantify in monetary terms and as such the costs of impacts can be considered to be considerably higher than those estimated. It would not be amiss to assume that the costs of IAS are comparable or even significantly higher than the impacts associated with Climate Change, one of the biggest challenges of our time. Despite the significant impacts of IAS and benefits of management there has been comparably little investment by donors and governments around the world in IAS control. This can possibly be attributed to the dearth of information on the financial impacts of IAS and the benefits of management. That said, studies which have been undertaken indicate that most investments in management yield positive returns. For example, management of invasive woody alien plants, many of which are consumptive water-users, has been shown to be an excellent investment even when just considering water savings alone (Le Maitre et al., 2002; van Wilgen et al., 2008; Currie et al., 2009). De Wit et al. (2001) were able to demonstrate that management of an invasive tree, Acacia mearnsii, in South Africa, would yield excellent returns while control of Miconia calvescens in Hawaii would yield a net present value benefit of US £34.5 million (Burnett et al., 2007). To date no studies have been undertaken on the costs and benefits of IAS management in the Caribbean. This may partly explain why there has been negligible funding to combat the onslaught of these exotic species in the region. As a result it was decided to provide individuals involved in the UNEP-GEF Project, "Mitigating the Threats of Invasive Alien Species in the Insular Caribbean" with training and an opportunity to undertake Cost-Benefit Analyses (CBAs) on some selected IAS. The CBAs undertaken and reported in this publication clearly demonstrates that the benefits of managing IAS outweigh the costs. Investing in IAS management is definitely a good investment for any donor or Government to make - it makes financial sense to do so! Wouldn't you invest in a programme/project with such excellent positive returns? We can turn things around; we can manage IAS and do so cost-effectively for the benefit of people and the environment. I hope that these case studies will go a long way in convincing those in the Caribbean and elsewhere that may believe otherwise.