Invasive Coralita Threatens Biodiversity Dutch Caribbean

Coralita is an ornamental plant that was introduced to several Caribbean islands but has quickly found its way to the top of the invasive species lists for the Dutch Caribbean.  Its fast-growing vines smother and outcompete native vegetation, changing the landscape of the islands. Conservation efforts include manual removal, herbicides, and awareness campaigns.

It is easy to fall in love with coralita. This ornamental plant, also known as the coral vine (Antigonon leptopus) was introduced to several Caribbean islands as a garden accessory in the 1940s.  Its brightly colored flowers and quickly growing vines make quite the statement piece in any garden. In its native territory, growth of this plant is limited by droughts, however, in the Dutch Caribbean this plant has been flourishing. Within the Dutch Caribbean, coralita has been able to spread quickly, year-round, due to its ability to grow near water collection points such as drainage channels.

Consequences

Coralita can spread very quickly. Its vines can reach up to 15 meters in length and rapidly cover entire areas of land. This vine is able spread both horizontally (across fields) or vertically (up trees and buildings), smothering native vegetation beneath it. In addition, this decrease in native flora is also impacting local insect and spider communities.  In fact, researchers from the Vrije Universiteit Amsterdam were able to demonstrate that on St. Eustatius, in areas of dense coralita, there was a decrease in native insects and spiders. Although often thought of as pests, these creatures play a critical role in the local ecosystem by serving as pollinators, aiding in decomposition and nutrient cycling as well as serving as a food source for native reptiles and birds.  A decrease in native vegetation and thus a decrease in insects and spiders will have a cascading effect in limiting the biodiversity of these islands in the future.

 

Innovative Ideas

Luckily, islands have some creative ways of combating this issue. In 2018, individuals from the St. John’s community on Saba planted five lemon trees to bring attention to and work towards the eradication of the invasive vine.  Land was selected and cleared, to be used as a fruit orchard, both working to eliminate coralita and provide a source of fresh fruit for the island. Overall, this project served to encourage community action (planting lemon trees) to achieve a common goal (removing coralita).

The ReLeaf team on Saba has begun planting along the road to Fort Bay where the Agricultural Department stopped planting, beginning with century plants.  Once established, Releaf will continue planting sea grapes, white cedar, and water mampoo to create a canopy that will shade out the coralita.

On St. Eustatius, researchers have found a novel way to use a classification map to help managers quickly identify dense areas of coralita.  Using this method, they showed that coralita is not randomly spread across the island, but is typically found along roads and drainage channels.  Overall, the vine was found more commonly in grasslands, disturbed natural areas, and urban sites and rarely in undisturbed natural forests. This information will be key in constructing invasive species management for the island.

Future work

The impact of coralita on the Dutch Caribbean is significant. It not only threatens the biodiversity of the islands, but it also has economic consequences, such as reduced tourism appeal and increased costs of removal efforts. Education is an important first step to getting involved in local conservation efforts. Current efforts include manual removal by trained volunteers and the use of herbicides to control the plant’s growth. In addition, awareness campaigns are being conducted to educate residents and visitors on the importance of protecting native vegetation and preventing the spread of invasive species.

Dutch Caribbean Biodiversity Database