Microbeads are tiny, smooth, plastic spheres found in common household products such as facial soap. These beads, measuring from 0.0004 to 1.24 mm, roughly the size of some fish eggs, are too small to be removed by water treatment systems. Thus, they end up in rivers, lakes, and other bodies of water. The accumulation of these microbeads is an environmental concern for aquatic biologists because microbeads (1) make the lakes and rivers cloudy and dirty, affecting their appearance
(2) may stick to some household water pipes, preventing drainage problems
(3) could be mistaken for food by some species, working their way up the food chain
(4) could clog fishing nets, affecting the ability of fishermen to catch fish

(3) could be mistaken for food by some species, working their way up the food chain

Explanation:

Microbeads, such as other microplastics, can affect wildlife in many ways, but mostly by

Organisms like mollusks, crustaceans, fishes, birds, turtles, among many others, might confuse these elements with food and eat them. Microbeads might float or accumulate in sediments and be ingested by different benthonic species. The ingestion of microbeads by inferior links in the trophic web means a direct entrance in the trophic web where many superior links are affected too while feeding with already contaminated prey.

The ingestion of microbeads can cause a significant impact on the growth, development, and reproduction of freshwater and seawater species.  

Microbeads, like other microplastics, characterize for their durability in time and resistance, which means that the ones that are already in the oceans and rivers will last there for centuries.