Abstract
► Boring sphaeromatid isopods destroy expanded polystyrene foam floats under docks. ► Boring damage was observed in multiple sites in Asia, Australia, Panama and the USA. ► An adult isopod expels thousands of microplastic particles when creating a burrow. ► Microplastics similar to these are consumed and may be toxic to fauna. ► Floats made of extruded polystyrene inhibit burrowing damage by isopods.
Boring isopods damage expanded polystyrene floats under docks and, in the process, expel copious numbers of microplastic particles. This paper describes the impacts of boring isopods in aquaculture facilities and docks, quantifies and discusses the implications of these microplastics, and tests if an alternate foam type prevents boring. Floats from aquaculture facilities and docks were heavily damaged by thousands of isopods and their burrows. Multiple sites in Asia, Australia, Panama, and the USA exhibited evidence of isopod damage. One isopod creates thousands of microplastic particles when excavating a burrow; colonies can expel millions of particles. Microplastics similar in size to these particles may facilitate the spread of non-native species or be ingested by organisms causing physical or toxicological harm. Extruded polystyrene inhibited boring, suggesting this foam may prevent damage in the field. These results reveal boring isopods cause widespread damage to docks and are a novel source of microplastic pollution.