We hope that you have enjoyed our ‘Planet Plastic’ blog series – welcome to the third and final post! The Darwin Plus project featured in this post is working with communities in the British Indian Ocean Territories to reduce their use of single-use plastics in an effort to save globally important sea turtles.

If you would like to read the entire ‘Planet Plastic’ series, please follow the links for the first and second blog posts.

How to protect sea turtles from plastics in the British Indian Ocean Territories

The British Indian Ocean Territory (BIOT) covers 640,000km² of marine protected area including an archipelago of 58 beach-fringed tiny islands. These beaches are targets for breeding females from regionally important populations of green and hawksbill sea turtles. Although only one of the islands in the far south of the archipelago is inhabited (Diego Garcia), the beaches see large amounts of ocean-borne plastic washing ashore. Our new Darwin-Plus funded project seeks to understand and mitigate negative effects of plastic waste on sea turtles. The team partners the Zoological Society of London, Swansea University and the British Indian Ocean Territory administration.

Green turtle hatchlings found amongst plastic waste on beach, Credit – Nicole Esteban

Beach waste tends to aggregate between the high tide mark and just beyond the vegetation line at the top of the beach. This belt of beach is also the target for nesting sea turtles coming ashore to dig deep pits and lay hundreds of eggs. We know from other studies that plastic can impede sea turtle excavations, affect the conditions in the nest by changing the temperature and humidity of the sand, present a physical barrier when hatchlings emerge from the nest, and be an inadvertent source of food for surface-feeding, omnivorous hatchlings.

The project team visited BIOT in June 2019 to start characterising and determining the origin of beach plastic waste. Comparing data from waste collected during beach cleans in Diego Garcia with that still in-situ on the beaches in both Diego Garcia and Egmont atolls, over 80% was found to fall into three categories: polystyrene pieces, flips flops and single-use plastic bottles. Plastic bottles had labels originating from 17 countries from Japan to Tanzania with the largest contributor being Indonesia, almost 3000km to the west.

BIOT DPLUS090 Marine debris washed ashore on Ile Parasol beach on Peros Banhos Atoll,   Credit – Dan Bayley

In addition to investigating beach waste, we are exploring how people stationed on Diego Garcia can reduce their use of single-use plastic. To achieve this, we are bringing experience from our #OneLess campaign, working to eliminate the need for plastic bottled water in London by creating a new system in which people use refillable bottles and tap water. Our key messages relate to the global need to reduce the amount of plastics, the importance of taking responsibility for our plastic use, and that everyday actions and decisions around plastic impact the ocean.

BIOT shares many challenges with other Overseas Territories – small islands in remote locations, difficult and expensive logistics, limited resources, and challenges with waste management. Dealing with ocean-borne plastic waste adds another burden, so as we explore recycling options, these need to incorporate clever technology and be operable in these conditions – preferably in a way that creates further useful and economically beneficial products. Our aim is by the end of this project to have identified suitable possibilities that could work not only in BIOT but potentially across the other Overseas Territories as well.

Further information on project DPLUS090 led by ZSL in BIOT can be found here. To read the full article or this project and others that were featured in our August edition of the Darwin Newsletter, please click here.