Plastic pollution threatens rhinos

Kathmandu, Aug. 22: Plastic pollution has emerged as a significant threat to wildlife in Nepal, including in protected areas. Recent research has uncovered a troubling issue -- plastic particles are making their way into the dung of greater one-horned rhinos. These plastic fragments found in the rhino droppings signal potential health risks for these majestic creatures.

The plastic comes from rivers during floods and ends up in the protected areas. This is a big issue because wild animals, including rhinos, ingest plastic while grazing. 

A recent study, “Plastic ingestion by greater one-horned rhinos in Nepal: An emerging conservation threat,” published in the journal Global Ecology and Conservation, has revealed that rhinos in a park swallow plastic items of various sizes and shapes. 

The research examined 258 dung samples, and about 10.1 per cent of them contained visible plastic, said Balram Awasthi, lead author of the study and a Ph.D. student at the Chinese Academy of Sciences Xishuangbanna Tropical Botanical Garden.

Awasthi, who was studying the ecological services of rhinos like seed dispersal, expressed surprise at finding plastic in their dung. He mentioned, “While researching the ecological roles of megafauna such as rhinos, I noticed a considerable amount of plastic in their dung.”

Talking to The Rising Nepal, Awasti said, “Plastic pollution is a big reason why many marine animals, like whales, are dying. However, we did not know as much about how it affects animals on land. Plastic breaks down slowly and is everywhere in nature, which means it is probably causing big problems for land animals too. The little bit of research that has been done shows that plastic is a serious issue for some animals that live on land.”

“We collected samples from two habitats – floodplain grassland and riverine forests. Rhinos use specific areas to defecate, and we checked fresh dung there, identified by its colour or by observing rhinos or dung beetles,” he said.

The research team discovered plastic objects like balls, bottle caps, tobacco pouches, polythene bags, and packaging from snacks and shampoos in the rhino dung.

The study, spanning the monsoon and post-monsoon seasons of 2020, 2021, and 2022, focused on the Chitwan National Park and its peripheral zone. Over these three years, researchers found plastic in about 10 per cent of the 258 rhino dung piles examined. This figure, however, likely underestimates the extent of the issue, as it did not account for micro-particles and did not involve a comprehensive search of the entire dung samples, Awasti informed.

Plastic pollution is a big problem, especially in the rivers and canals. It harms aquatic life as well as the ecosystem, said Dr. Babu Ram Lamichhane, one of the researchers. 

Now we are learning that plastic pollution does not only hurt aquatic creatures but is also a big problem for animals on land, like the large one-horned rhino. “While we’ve focused a lot on how plastic affects the rivers, oceans and seas, we have not studied as much about its impact on land. But the research is showing us that plastic is causing issues for animals that live on the ground too,” wildlife expert Dr. Lamichhane said.

This indicates that plastic pollution infiltrates the rhino’s habitat through other means, primarily through rivers during monsoonal floods. As floodwaters retreat, the plastic is deposited within the rhino habitat. The researchers found more plastic in dung samples from the park’s restricted core zone (18 per cent) compared to the more populated fringe zone (6 per cent).

“This is concerning because we found more plastic in rhino poop in the main part of the park, not the edges. The way the rhinos move might explain this, and it could also be a problem for other animals by the rivers,” he said.

The findings of the study are important for more than just rhinos. “We want to look closely at how plastic affects not only rhinos but also other animals. Plastic can block animals’ insides and make them sick or even cause death,” Awasti said.

 “It’s a reminder that we need to think about everything that affects animals and their homes. We should protect them not only from things like poaching and losing their homes but also from hidden dangers like plastic pollution,” Dr. Lamichhane said.

When scientists, leaders, and communities understand how plastic hurts big animals on land and in their homes, they can work together to find good solutions. This way, we can make sure these amazing animals stay safe and the places they live in stay healthy too.