The quantity of plastics and marine debris in the Kingston Harbour area and its effect on the natural environment is alarming. However marine organisms are often trapped, suffocated, ensnared and killed by plastic debris.

The plastic debris also damages young plants such as mangrove seedlings and hinder the restoration work that has been done along the Palisadoes roadway. The effects of such large amounts of plastic materials in the environment will also lead to declines in fish stocks as toxins leach from the plastics into the water. However, the threat is increased by the presence of micro-plastic debris which are ≤5 mm sized particles. These particles are produced in areas with large deposits of plastic waste as the sun and wave action act to fragment the large items. The micro-plastics are of the size that can be eaten by fish, oysters and plankton and so can cause greater contamination of fish stocks. The micro-plastic contamination has the potential to enter the food chain and eventually be eaten by man.

The quantities of micro-plastics in the mangrove waters of the Kingston harbor are being determined for the first time by Professor Mona Webber, Director of the Centre for Marine Sciences in collaboration with Ms. Deanna Rose a Research Scientist at International Centre for Environment and Nuclear Sciences (ICENS). Sampling commenced in February 2017 and preliminary results indicate that in some stations micro-plastics represent 25% of the total "plankton" and so could be encountered 25% of the time by fish, oysters and other filter feeders.

Sampling involves towing a plankton net which is modified to float at the surface. The project has benefitted from a loan of a Manta Trawl from 5Gyres Inc. which has allowed for the use of gear that is internationally applied to micro-plastic sampling.

Refuge Cay forms one of the few completely isolated mangrove islands in the Port Royal Mangroves of Kingston Harbour. Consequently, it is home to numerous species of birds which roost and nest in the canopy of the mangrove trees, and also provides a nursery area and feeding ground for aquatic organisms (snapper, snook, jack, shrimp, oysters and lobsters). Refuge cay also forms the north-western border of Hurricane Refuge Lagoon which has provided safe anchorage for large vessels during hurricanes.

Refuge Cay is heavily impacted by solid waste, especially on its north shore, which faces the Kingston Harbour. This has caused the mangrove forest to die in the centre of the cay as the forest is cut off from regular water flow by the build-up of debris. The loss of the mangrove forest cover will see eventual loss of the entire cay and its associated ecological and economic value. An immediate intervention for the rehabilitation of Refuge Cay has been designed which involves removal the solid waste so the free-flow of water is restored and to install solid waste barriers to prevent re-deposition.

The planned intervention to achieve effective rehabilitation may require replanting of seedlings in the cleaned areas of the cay. Work around Refuge Cay began in July, 2017 and the James Moss Solomon Senior Chair and the Centre for Marine Sciences, UWI received a grant from the Kingston Freeport Terminal Limited (KFTL) to carry out the rehabilitation activities.

To date, with the assistance of 23 fishers from Port Royal, a total of over 8200 bags of garbage have been removed from Refuge Cay.