Microplastics, which are plastic pieces smaller than 5 mm, are commonly found in the marine environment, where they are available for ingestion by marine fauna. Because of both their root structure and their geographic distribution, mangrove forests are known as sinks of microplastics, but very little is known about the factors controlling the microplastics ingestion by mangrove associated crabs, which are a dominant and ecologically relevant ecosystem component. We observed that both the level of plastic contamination in the mangrove and the feeding habit of the crab's species play critical roles in the abundance and type of microplastic ingested by mangrove crabs.
AbstractAs marine plastic debris is primarily sourced from terrestrial input, coastal environments are particularly affected by deposition. Because of their pneumatophores, mangroves have been recognized for their importance in confining plastic waste. Crabs are a dominant component of the mangrove ecosystem and play a critical role in maintaining healthy and resilient mangrove forests. Therefore, the presence of debris fragmented from waste, in their habitat is a potential threat. However, the potential ingestion of microplastic pieces by mangrove crabs has not yet been investigated. Here, we quantified microparticles found in the cardiac stomachs and gill chambers of four species of crabs. All specimens collected had anthropogenic microparticles present either via their digestive or respiratory systems. We observed significant variability in the abundance and types of anthropogenic microparticles across sites and species. Interspecific differences appear to be explained by their particular feeding habits, with less selective species ingesting more particles.