With millions of tons of plastic reaching the world’s oceans, the risk that it can carry disease is increasing.
We are experiencing a very difficult period caused by the worldwide spread of Sars-Cov-2 virus (the coronavirus causing COVID-19 disease). This pandemic is one of the effects of the destruction of habitats that lead the human population to come into contact with pathogens that, until recently, were isolated in wild and pristine areas.
At sea, microplastic fragments differ greatly from natural floating particles. Plastic particles are known to transport combinations of metals, pollutants and pathogens (bacteria, viruses and other microorganisms that can cause disease).
Several studies have found strains of bacteria resistant to antimicrobials in concentrations from 100 to 5,000 times higher on microplastic surfaces than the surrounding seawater.
With the current data, unfortunately, we still do not know how bacterial colonies and viruses, present on oceanic microplastics (read here), can affect the health of humans and animals.
More and more vibrions
A recent study has identified that bacteria of the genus Vibrio, a globally spread group of human and animal pathogens (well known is Vibrio cholerae, cause of cholera), are increasing their spread and have been found in high levels on microplastics.
These bacteria can pose a major threat to bivalve mollusc farms. These molluscs, in fact, are filter organisms and are known to absorb microplastics from seawater (read here). Vibrions can lead to infections and death of mussels, with consequent negative effects on the industry, the market and increasing health risks for consumers.
Study and act
Understanding the link between microplastics and the risk of pathogen transfer through shellfish (and fish in general) is crucial for the aquaculture industry and human health.
We urgently need to move to more sustainable and circular economic approaches than the current use of plastic materials. Drastically reducing the release of plastics into the environment is necessary to avoid more serious future problems.
1 Jake Bowley, Craig Baker-Austin, Adam Porter, Rachel Hartnell, Ceri Lewis. Oceanic Hitchhikers – Assessing Pathogen Risks from Marine Microplastic. Trends in Microbiology, 2020; DOI: 10.1016/j.tim.2020.06.011