Researchers have discovered microplastic particles adhering to the gills and inside the digestive systems of pirarucu fish in the Amazon River basin [1, 2].
This contamination indicates that plastic pollution has permeated the deep aquatic ecosystems of the Amazon, potentially threatening the health of one of the region's most iconic species.
The studies, reported this month and last month, focused on the pirarucu, also known as the Arapaima gigas [3, 4]. These large fish can weigh up to 200 kilograms [5]. Scientists said that tiny plastic particles were not only being ingested but were also sticking to the gills of the fish [2].
This physical adherence to the gills may cause respiratory complications for the animals. The presence of plastics within the digestive tract further suggests that the fish are consuming contaminated prey or water [1, 2]. The research specifically highlighted findings near Manaus, Brazil [1, 4].
The contamination is the result of widespread plastic pollution throughout the Amazon watershed [3, 2]. These microplastics enter the river system and become trapped in river plants before moving up the food chain into the fish [2].
Researchers said that the particles are pervasive across different environments, moving from the rivers into mangroves [3]. The ability of these particles to lodge in respiratory organs suggests a direct impact on the biological functions of the pirarucu [1, 2].
“Microplastic particles have been found adhering to the gills of pirarucu.”
The discovery of microplastics in the pirarucu suggests that plastic pollution is no longer limited to surface waters or coastal areas but has integrated into the biological processes of apex predators in the Amazon. Because the pirarucu is a vital part of the river's ecology and a food source for local communities, this contamination may signal broader risks to biodiversity and human food security in the region.
