Multiple impacts of microplastics can threaten marine habitat-forming species

Microplastics are recognised as a potential global threat to marine ecosystems, but the biological mechanisms determining their impact on marine life are still largely unknown. Here, we investigated the effects of microplastics on the red coral, a long-lived habitat-forming organism belonging to the Corallium genus, which is present at almost all latitudes from shallow-water to deep-sea habitats. When exposed to microplastics, corals preferentially ingest polypropylene, with multiple biological effects, from feeding impairment to mucus production and altered gene expression. Microplastics can alter the coral microbiome directly and indirectly by causing tissue abrasions that allow the proliferation of opportunistic bacteria. These multiple effects suggest that microplastics at the concentrations present in some marine areas and predicted for most oceans in the coming decades, can ultimately cause coral death. Other habitat-forming suspension-feeding species are likely subjected to similar impacts, which may act synergistically with climate-driven events primarily responsible for mass mortalities. Corinaldesi et al. investigated the biological responses to microplastic contamination of the red coral Corallium rubrum, a genus with near global distribution. Microplastics caused feeding impairment, tissue damage, altered gene expression, oxidative DNA damage and microbiome alteration. Such diverse deleterious effects may be generalizable to other habitat-forming suspension and filter feeders given the burgeoning levels of microplastic contamination across the world's oceans.

Automated summary

The study found that microplastics have various harmful effects on red corals, including feeding impairment, tissue damage, altered gene expression, oxidative DNA damage, and changes in the microbiome. These diverse effects may be applicable to other habitat-forming suspension and filter feeders due to the increasing levels of microplastic contamination in the world's oceans.