Abstract:
Approximately 4.8 to 12.7 million tonnes of plastics enter the marine environment annually
contributing to 5 trillion pieces of plastic in the global oceans and surface waters. Plastics in
the marine environment can exist as macro, meso, and microplastics and due to its durability
and longevity, once they are introduced into the environment, it can persist and be distributed
globally by ocean currents and winds. Regardless of the high abundance of plastic pollution in
the environment and its various negative impacts on marine ecosystems, human health, and
the economy of countries such as the Maldives that depend on biodiversity-based economic
sectors such as tourism and fisheries, research regarding causes of plastic pollution and
sources of microplastics and its abundance is scarce. This study aims to quantify microplastic
pollution in the Maldives and to identify sources of plastic pollution by investigating the
effects of land-use and ocean currents on plastic pollution in the Maldives.
A combination of field and laboratory methods was used to collect beach sediment samples,
log macro and mesoplastics and to isolate, identify and quantify microplastic pollution on
three different islands of varying land-use intensity (Industrial, Urban and Rural) in the
Maldives. Additionally, Geographic Information System (GIS) was used to map ocean
currents and identify the influence of ocean currents on microplastic distribution on the
Maldivian islands.
The results of this study shows that there is a significant level of microplastic pollution at the
studied islands: K. Thulusdhoo, K. Villingli and B. Dhonfanu. Additionally, it also showed
that the pollution levels at these three islands were higher compared to other coastal areas in
the Indian Ocean, as well as other regions of the world. Furthermore, the results showed that
the microplastic abundance at Thulusdhoo, an industrial island, was statistically different to
both Dhonfanu which is a rural island and the urban island, Villingili proving that land-use
influences plastic pollution. However, the difference between the Urban and Rural islands,
despite the Urban island having a higher microplastic abundance was not significant,
indicating that other factors such as ocean currents also influence microplastic abundance. The
ocean current direction and speed along with the difference in the shape and size of
microplastic found on the islands proves that ocean currents were also an influencing factor in
microplastic abundance on the Maldivian islands.
