Multiple impacts of microplastics can threaten marine habitat-forming species

Carlo Cerrano,Sara Canensi,Trevor J Willis,Michael Tangherlini,Antonio Dell’Anno,Stefano Varrella,Roberto Danovaro,Iole Di Capua,Cinzia Corinaldesi

doi:10.1038/s42003-021-01961-1

Carlo Cerrano, Sara Canensi + Show 7 more

Open Access

https://doi.org/10.1038/s42003-021-01961-1

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Abstract

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.

Highlights

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
The microplastic concentrations available to C. rubrum, determined from the analysis conducted in the CTRL MPS, were, on average, 602–633 microplastic particles L−1, within the first 14 days of experiments
The lowest microplastic concentrations in our experimental systems fall within the range estimated for the area where corals were collected and in other marine environments[7,8,10]

Summary

Introduction

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. 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 cause coral death. Available information is still primarily based on toxicological assays[20] typically carried out using selected polymer microspheres/beads, marked with contaminants or fluorescent probes[7,29] Since these tests may not reflect natural conditions[20], there is a need for the development of experimental studies able to mimic natural conditions, combining laboratory controls with multidisciplinary approaches that can provide a more comprehensive understanding of the molecular, cellular, physiological, behavioural and ecological implications[8,20,30]. The genus Corallium is distributed worldwide, at almost all latitudes, spanning Antarctica, the northern Pacific (Hawaii, Japan), the southern Pacific (New Zealand, Tasmania), the equatorial latitudes (Taiwan), the eastern Pacific, the western Atlantic and the Mediterranean Sea[32,33,34]

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