Study provides first holistic assessment of plastic pollution in Caribbean

The Caribbean is renowned globally for its stunning beaches and crystal clear ocean.

However, its islands and the surrounding sea are being contaminated by plastics and other manmade fibres, posing a potential future threat to its diverse marine life and the tourism industry on which its economy depends.

That is according to a new study, the first holistic assessment of marine and land-based plastic pollution in the southern Caribbean and some of the environmental and human factors which might influence its distribution.

The study is the result of sample analysis from a pioneering all-female Round the World sailing mission led by eXXpedition. Samples were collected in late 2019 from the seas and seafloor, and from land-based assessments.

Off the coast of five Caribbean countries, it identified 18 different polymers of plastic - including, synthetic fibres, paint flakes and acrylics - in waters across the Caribbean, with the highest concentrations (5.09 particles per m³) located off the San Blas islands in Panama.

Detailed ocean modelling and an assessment of regional policies indicated the abundance of microplastics in the area likely arose from a combination of distant sources carried by ocean currents and run-off from mainland Panama, which has some of the highest estimated levels (around 44%) of mismanaged waste in the region.

By contrast, the waters off Antigua, Bonaire and Colombia had lower quantities of terrestrial and marine plastics. Antigua, in particular, had a high diversity of polymers, with the research suggesting the majority of the microplastics collected were likely to have been transported by currents generated in the wider North Atlantic Ocean, even originating in the so-called North Atlantic garbage patch.

Writing in Science of the Total Environment, the study's authors suggest both terrestrial litter and the microplastics identified in marine samples may arise from the maritime and tourism industries.

That in turn, they say, represents the complex challenges of managing plastic pollution since both are major contributors to the economies of the Caribbean region.

The research was led by scientists at the University of Plymouth (UK) in conjunction with the University of Georgia (USA), Plymouth Marine Laboratory (UK) and the Technological University of Panama.

eXXpedition's Round the World voyage left Plymouth in October 2019 to visit some of the most important and diverse marine environments on the planet with the aim of inspiring a network of changemakers, informing effective solutions with industry and influencing policy change on land.

The University of Plymouth was the first to highlight the global problem of marine microplastics - earning the Queen's Anniversary Prize for Higher and Further Education in 2019 - and was recently named the leading university in the world for marine research and teaching.

Professor Richard Thompson OBE, Head of the International Marine Litter Research Unit and senior author on the study, added:

"It is now very clear that plastic litter presents a global environmental problem. There are changes we can all make in our everyday lives to help address that challenge. However, it is only by gaining a better understanding of how plastic debris passes from its source to the ocean that we will be fully equipped to tackle the problem."

• The full study - Courtene-Jones et al: Source, Sea and Sink - a holistic approach to understanding plastic pollution in the Southern Caribbean - is published in Science of the Total Environment, DOI: 10.1016/j.scitotenv.2021.149098.