A study published in PLOS One demonstrates that tiny plastic particles in the oceans can alter how scientists measure and understand the ocean carbon cycle. The authors find that microplastics collected with natural organic particles release carbon during combustion that appears the same as carbon from natural organic matter. As a result, routine analytical tools for carbon analysis cannot reliably distinguish plastic-derived carbon from biological carbon.
Researchers used a standard set of analytical methods to measure carbon content in water and sediment samples and then calculated carbon yield from both microplastic contaminants and sedimentary organic matter. The study explains that microplastics reach the sea when larger plastics break down and also from products made for cosmetics and industrial uses; they arrive via rivers, wastewater, and runoff and then spread through coastal and open-ocean waters.
The authors describe how microfibers from clothing and plastic particles from sampling, storage and processing gear can enter samples unnoticed and become part of measured carbon inventories. They warn that plastic carbon may quietly distort decades of ocean carbon measurements and affect the models used to predict climate-related changes. The paper emphasizes the need to re-evaluate best practices for processing organic matter samples for carbon analysis. The research was supported in part by grants from the National Science Foundation.
Difficult words
- microplastic — very small pieces of plastic in watermicroplastics
- combustion — process of burning something to produce heat
- organic matter — material from living or once-living organisms
- carbon cycle — natural movement of carbon through Earth systems
- contaminant — a substance that makes something impurecontaminants
- distort — change facts so they appear incorrect
- re-evaluate — examine again to judge or change
Tip: hover, focus or tap highlighted words in the article to see quick definitions while you read or listen.
Discussion questions
- What changes in laboratory practices might reduce microplastic contamination in carbon analysis? Give one or two examples.
- How could distorted ocean carbon measurements affect predictions about climate change? Explain briefly.
- What public or policy actions could help reduce the flow of microplastics into rivers and the ocean? Give one suggestion and a reason.
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