Microplastics are commonly ingested by marine animals but there have been few studies on how they may change behavior patterns and predator-prey interactions. Scientists have now shown that the ingestion of microplastics, such as microbeads, is harmful to the survival of beachhoppers. The details are in a paper that was just published in the journal Marine Biology.
Plastic particles smaller than 5 mm are often referred to as “microplastics”. While some microplastics are the result of larger plastic materials breaking down, most are from the shipping, clothing, and cosmetics industries. In cosmetics, tiny plastic beads called “microbeads” are used as exfoliators in face washes and soaps. Microplastics are also shed from nylon clothing and other synthetic fibers. These pollutants persist in the environment, usually ending up in the ocean. Animals may then ingest or breathe in the plastics, leading to a host of potential health problems.
A team of researchers from Macquarie University investigated the effect of microplastics on tiny organisms called beachhoppers (Platorchestia smithi). Beachhoppers are crustaceans often seen hopping around in the sand. They consume decomposing seaweed and are an important food source for other marine animals. The team exposed the animals to microplastics to investigate possible effects of ingestion.
The team found that the beachhoppers were quick to ingest the microplastics. The pollutants rapidly accumulated in the animals’ bodies. The beachhoppers that had consumed microplastics were weighed down, resulting in slower movement and reduced jump heights. This made the animals more vulnerable to predation since jumping is an important escape tactic for beachhoppers.
Microplastics are common pollutants in the ocean but many of the effects on marine organisms are poorly understood. Beachhoppers readily ingest the tiny plastics and the pollutants build up in their bodies. This decreases the height of their jumps, reducing the chance of escaping predators. Since beachhoppers are a major food source for other coastal animals, the effects of microplastics may be felt throughout the local ecosystem.
Louise Tosetto et al. Microplastics on beaches: ingestion and behavioural consequences for beachhoppers. Marine Biology (2016).