Sat | Aug 29, 2015

NEPA takes fight to alien invaders

Published:Wednesday | October 27, 2010
The Pacific lionfish has migrated to the Jamaican waters and can be dangerous to divers.
Lionfish - contributed photos
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Philip Hamilton, Gleaner Writer

The National Environment and Planning Agency (NEPA) is exploring measures to halt the spread of invasive alien species in Jamaica.

The proliferation of invasive alien species in the island is causing a severe headache for environmentalists and agriculturalists working to stem the threat to local plant and animal populations.

Such invaders negatively impact other established plants and animals by competing with them for food and habitat.

The lionfish, which is native to the Indo-Pacific region and is one of the more popular invasive alien species discovered in Jamaican coastal waters nearly two years ago, is said to be threatening the livelihood of local fishermen, frequently disturbing fishing pots and nets.

A voracious predator, an adult lionfish can devour up to 10 juvenile fish within an hour.

Nelsa English, NEPA's national project coordinator, noted that invasive species were generally very resilient, and were capable of withstanding harsher conditions than their native counterparts.

"Once they have established themselves, they spend considerable effort reproducing in large numbers, especially animals. Plants spread by seeds and rhizomes, aided by people and wind dispersal," she told The Gleaner.

Historical problem

The presence of invasive alien species in Jamaica dates back to Spanish and British occupation of the island when colonisers brought non-native plants and animals to the island.

English said invasive alien species are introduced both intentionally or unintentionally.

"Persons who travel may see a plant they like, break off a piece and stash it in their suitcase. After it begins to grow profusely in their backyard, they don't want it anymore, cut it and throw it away, which causes it to spread," she explained.

English said international trade accounts for the biggest movers of invasive alien species worldwide, many of which travel as 'stowaways' in the ballast water of ships, which are later discharged in foreign ports.

An example of this is the mellaluca, or Australian paper bark tree, which thrives in wetland areas. It is common in the Lower Black River Morass, the largest freshwater ecosystem in Jamaica, which is already under threat from the draining of the land for agricultural or tourist development.

The NEPA project coordinator said these trees, which absorb a lot of water and disperse several seeds, could put other wetland life at risk if not controlled, similarly to what occurred in the Florida Everglades.

Water hyacinth

The proliferation of another invasive species in the Lower Black River Morass, the water hyacinth, has been cause for concern for the National Irrigation Commission, which has spent hundreds of thousands of dollars unclogging drains and irrigation channels. The plant also blocks sunlight from reaching native aquatic plants, starving the water of oxygen and thus killing fish and other organisms.

English said recent research by the University of the West Indies marine labs in Discovery Bay and Port Royal has uncovered solutions to reduce the threat caused by the green mussel.

She said NEPA is currently working on a national invasive species strategy document which will serve as blueprint outlining measures for preventing invasive species from entering Jamaica.

"We're looking at prevention and early detection, eradication, control and management to see how best, as a country, we can control the population of these invasives that they don't post a threat to our local biodiversity," English said.

philip.hamilton@gleanerjm.com