Why Plastics are Bad News for Filter Feeders
I study large filter feeding fish, mostly mobulid rays and whale sharks. To feed, these animals take in large quantities of seawater through a specialized filtering structure in their mouths. This filter allows them to keep small nutritious animals, such as zooplankton, fish eggs and larvae, and dispel excess water. Although filter-feeding animals have varying techniques, none are known to be able to differentiate food from microplastics. Not only are microplastics able sneak through evolutionarily perfected filters, but even the smallest animals, like zooplankton (the very source of food for filter feeders), ingest microplastics. Furthermore, the sponge-like quality of microplastic attracts pollutants. Over time, exposure to microplastics and toxins will amplify as these compounds become entrenched in food webs.