Did you know that the annual microplastic contamination in terrestrial and freshwater environments could be 4–23 times higher than in marine environments?

The proof was in 278 fishing cat scat samples collected from Beddagana Wetland Park in Kotte, Sri Lanka, as part of a more comprehensive dietary study led by Anya Ratnayaka. Fishing Cats (Prionailurus viverrinus) are obligate generalist carnivores and skilled hunters – their diet consists of a variety of prey. In wetlands, this includes rodents, fish and birds. Published in “Environmental Pollution in 2023”, Ratnayaka et al. found low microplastics, mesoplastics and macroplastics in every fishing cat scat sample collected and analysed. The cats are not scavengers of garbage – pointing to one thing proof of plastic accumulation in wetland food webs and plastic pollution in freshwater terrestrial ecosystems in Sri Lanka.

The effect of plastic invasion is different in each ecosystem, determined by how the organisms within them biologically interact with it . Because microplastics are less than 5 mm in length, it’s easily ingested by the smallest fish and invertebrates, which are then consumed by larger fish, birds or mammals. Microplastics moving up the food webs through trophic transfer has cascading effects on an ecosystem, especially for apex predators like the Fishing Cat.

Scientists have found microplastics everywhere; in wetlands, deep oceans, Arctic snow, shellfish, fishing cat scat, and even table salt! Although the effects of plastics on biodiversity and human health are extensively studied in marine ecosystems, little is known about the actual impacts of plastic pollution on terrestrial ecosystems.

Protecting habitats like urban wetlands from plastic pollution means being as pervasive as plastic to reduce our use of non-biodegradables and advocate for proper waste management practices from local authorities. The accumulation of plastic must be eradicated at its source before it spreads and changes face in terrestrial food webs.