Plastic debris beached on three coral reef islands in the Indian Ocean

K. Minnaar1*, H. Bouwman1 & R. Choong Kwet Yive2

1North-West University, Potchefstroom, South Africa2University of Mauritius, Mauritius

Plastic debris beached on three coral

reef islands in the Indian Ocean

Plastics

Why are they such big concern?

Science 2015

Raising awareness

Aim

• To investigate the presence and composition

of stranded marine debris on the shores of

three remote Mascerene islands

• To determine the spatial concentration

variations between up- and down-current

shores of each island; as well as the

differences between the islands

Sampling sites

Sampling sites

Agalega

St Brandon's Rock

Rodrigues

Mauritius

Reunion

20S 80E

200 km

Plastic transects

+/- 100 m

Previous study

Results

Results

Results

F1: Nonmetric multidimensional scaling (NMS) of the debris deposits on the up-current

(red) and down-current (green) aspects of Rodrigues

Results

F2: The up-current (red) and down-current (green) beached debris on Agalega (NMS)

Results

F3: Differences in debris deposits on the up-current (red) and down-current (green)

aspects of St. Brandon's Rock (NMS)

Results

F4: Variations in composition and concentration of beached debris on Rodrigues (red),

Agalega (green), and SBR (blue)

Conclusion

• Most common debris on all three islands:

– Plastic fragments

– Plastic bottles

– Bottle caps

• Large influx of debris from distant locations,

potentially hazardous to local ecosystems

• Large number of flip flops, and RB bottles indicate

possible origin of pollution on Aga and SBR

• SBR is the most vulnerable

• Interventions possible on Agalega, and has already

started on Rodrigues.

Future studies

• Investigate the presence of microplastic

particles on and around the Mascarene

islands

THANK YOU

• Special thank you to:

– PETCO (Sherry Scholtz)

– Plastics SA (John Kieser)