IAS Impact

Invasive Alien Species (IAS)


The impacts of IAS are felt in three main spheres—the environment, the economy and the society—as seen by their effects on biodiversity, trade, tourism, and agriculture.

Environmental Impact

Image by Bela Geletneky from Pixabay

As expected, the initial impact of IAS is seen in the destruction or disruption of the natural environment as explained below.

IAS outcompetes native species for habitat space and food source

Invasive alien plants and animals are typically more aggressive than native species and easily outcompete the latter for habitat space and food. One example being the lion fish that has invaded Caribbean waters in recent years with no significant natural predators in our environment their numbers have exploded. Feral donkeys, and cattle before they were eradicated in 2014 posed a significant threat to the Cyclura ricordi that is critically endangered present on Cabritos island in the Dominican Republic. Cats remain on the island and continue to pose a threat. Goats also posed a significant threat to biodiversity on the Redonda Island off the coast of Antigua and Barbuda. Luckily, they were recently removed with natural restorations is taking place.

 IAS prey on native species

Predatory IAS include dogs, pigs, mongooses, many of which were introduced at the time of colonization.  For example, Antigua & Barbuda has over 30 uninhabited offshore islands of global biodiversity importance home to endemic, critically endanger species such as Alsophis antiguae (Antiguan racer);  Pholidoscelis atrata (Redonda ground lizard), Anolis nubilus (Redonda tree lizard); Sphaerodactylus sp. nov. (Redonda pygmy gecko). Rats have threatened these species to near extinction.

IAS reduce biodiversity

Protein nutrition is generally held to be a major factor in bee health and immunity. Published research has confirmed that such nutrition is directly related to the diversity of pollen sources. Where bees are limited to a narrow selection of pollen sources, as is the case when ecosystems have been overtaken by invasive plants, the immune competence of bees is compromised leading to poor apiary health. This has implications for a wide range of crops that depend on bees for pollination.

Economic Impact

Image by Nattanan Kanchanaprat from Pixabay 

Of course, environmental destruction comes at a price. IAS-induced destruction of biodiversity will eventually compromise the productive capacity of natural resource-based industries, namely agriculture and tourism, two sectors Caribbean economies rely heavily on.

Millions of dollars in economic losses

Whereas precise data on economic losses for the Caribbean due to IAS are limited, in neighbouring Florida estimates indicate approximately US$1 billion in losses and expenditures to control outbreaks of IAS that affected agriculture between 1995 and 2001. Throughout the Caribbean, the Pink Hibiscus Mealybug outbreak in 1990’s was estimated to have caused US$138 million in crop losses, in addition to the expenditure for controlling the outbreak and lost export earnings. In Haiti, the reappearance of classical swine fever in 1996 resulted in the death of 80 percent of the swine population. The costs of the ongoing eradication programme in Haiti and the Dominican Republic have been estimated to have surpassed US$12.1 million.

Loss of habitats and species important to tourism industry

Many Caribbean islands are heavily dependent on tourism. An important segment of the tourism market is eco-tourism where visitors come to see our unique species and ecosystems.  Some IAS directly threaten the habitat of species that are important to the tourism industry for example rats and mongoose prey on the turtles that are an important attractant during the nesting period. At the same time, other types of IAS affect water-based recreational activities, such as the Sargassum sea weed that fouls up popular beaches forcing the closure of hotel and keeping away tourists. 

Social Impact

Image by rawpixel from Pixabay

IAS can also severely disrupt society, placing a burden on health systems and curtailing normal activities.

Significant impacts on activities and healthcare

Disease outbreaks can:

  • Restrict travel from and to affected areas
  • Disrupt school attendance
  • Limit hosting of public events
  • Increase the demands on public health care systems
  • Result in significant loss of productive man hours due to ill health.