Microplastics pollution in the sea and on beaches can be a big problem for sand crabs (Emerita analogous), small crustaceans that can be found in the sand of beaches especially in North and South America.
This crab has adapted well to living in the sand. Its own body shape, an elongated dome shape, is designed to dig quickly into the sand and even the antennae are long enough to protrude over the surface of the sand itself. It feeds on plankton that it assimilates by filtering the water itself on the shoreline. According to researchers at Portland State University, these animals suffer higher mortality and less reproductive success when exposed to microplastics.
So-called “microplastics” are plastic microfibers that result from pollution caused by this material. Sand crabs assimilate these microscopic fibers by filtering out water particles. Since sand crabs are very important for the ecosystems to which they belong, this can be a big problem. For example, sand crabs are a favorite prey of coastal birds, fish living around the coast and various marine mammals.
By assimilating more microplastics fibers in their bodies, these crabs have to suffer a higher mortality rate and the number of days that females can keep their eggs alive or viable also decreases, which also greatly affects breeding rates.
Furthermore, the same microplastics, as researchers have discovered, can also lower the embryonic development rates of these crustaceans.