Indonesian Projects.

Microplastics & Megafauna

What’s this project about?

MMF is studying the impacts of marine plastic pollution on manta rays and whale sharks to better understand the risk to these filter-feeders.

We have initially chosen to focus our research on Indonesia and the Philippines, two countries within the Coral Triangle, home to the planet’s richest biodiversity but is also one of the most polluted by plastic. We hope to leverage the iconic status and high blue economy value of manta rays and whale sharks for both of these countries to facilitate faster uptake in waste mitigation by governments and communities.

Objectives.

Starting in 2016, we investigated the levels of marine debris including microplastics in waters where manta rays and whale sharks are feeding in several locations across Indonesia.

We estimated the abundance of microplastics in surface waters where manta rays and whale sharks feed. Based on these estimates our findings suggest that manta rays could be ingesting on average ~ 60 pieces of plastic per hour of surface feeding in some of the studied locations. For whale sharks, it’s more than double at ~140 pieces per hour. There are more plastics during the wet season in these sites meaning that filter-feeders have a higher risk of plastic ingestion during this time of year.

We confirmed that plastic ingestion by manta rays occurs by collecting samples of egested material. Future work is also aimed at assessing manta ray and whale shark exposure to plastic-associated chemicals.

This project is capitalizing on the importance of healthy manta ray populations for the blue economy and ecotourism to nearby communities while raising awareness of the impacts of microplastics. We have surveyed local community stakeholders to establish a baseline on their current waste management attitudes and habits, provided outreach session about our findings so far, and followed up our surveys to understand changes in attitudes and perceptions of waste management. These insights will be used to inform local governments, organizations and stakeholders in an effort to improve local waste management policies.

Project Leaders.

Dr Elitza Garmanov
Senior Scientist

Elitza “Ellie” Germanov is MMF’s Senior Scientist who manages the Manta Ray project in Indonesia and founded and leads the Microplastics & Megafauna project. Ellie has been working with MMF since 2014 to provide critical information on habitat use, movements and threats to manta rays, and other threatened species that can be used in their conservation and the protection of the greater seascape. Her work has contributed to manta ray protection in Indonesia and the first assessments of the implications of microplastic pollution to manta rays and whale sharks.

See Elitza’s full bio here.

Janis Argeswara
Project Leader

Janis Argeswara is a Project Leader with MMF. Janis joined MMF in 2017 to assist on Microplastics and Megafauna Project and in 2018 she assessed the chemical makeup of microplastics in manta ray feeding grounds for her Bachelor thesis. Janis now leads the Manta Reproductive Ecology Project to better understand the reproductive patterns in Nusa Penida, a key reproductive ground for Indonesia’s manta rays.

See Janis’ full bio here.

Publications.

Microplastics in fecal samples of whale sharks (Rhincodon typus) and from surface water in the Philippines. Yong MMH, Leistenschneider C, Miranda JA, et al. Microplastics and Nanoplastics 1: 1–9.

What's in the soup? Visual characterization and polymer analysis of microplastics from an Indonesian manta ray feeding ground. Argeswara J, IG Hendrawan, IGBS Dharma, and E Germanov. Marine Pollution Bulletin 168: 112427.

Microplastics on the menu: plastics pollute Indonesian manta ray and whale shark feeding grounds. Germanov ES, Marshall AD, Hendrawan IG, et al. Frontiers in Marine Science 6.

Microplastics: No small problem for filter-feeding megafauna. Germanov ES, Marshall AD, Bejder L, Fossi MC and Loneragan NR. Trends in Ecology and Evolution 33(4).