Lia Corbett

Fate and impact of nanoplastics on marine microbes

We are living in an age of increasing anthropogenic plastic consumption. A large part of our plastic waste ends up in the oceans. Nanoplastics, a size distinction used to describe ultra-small pieces of plastic, are influenced by the marine environment differently than larger pieces of plastics. Therefore, marine microbes are driven to find ways to adapt and survive.

Nanoplastics: The unseen majority?

The ocean can often be a dynamic and volatile environment. Next to temperature extremes, there are nutrient fluctuations, varying depths, and leaching of land-based pollution, including plastic waste.

Plastic marine debris (PMD) can occur in various size ranges. According to recent estimates, approximately 99% of plastic debris that escapes to the ocean and other aquatic ecosystems is unaccounted for. This missing portion of marine plastic waste could exist in the form of plastic degradation products which are smaller than a thousand nanometers or a tenth of a millimeter. These degradation products can also be referred to as nanoplastics. Understanding the behavior and characteristics of nanoplastics is a critical step in assessing the possible environmental and ecosystem risk of plastic waste.

Culturing the Plastisphere

Professor Linda Amaral-Zettler has introduced the term ‘Plastisphere’: ecosystems of life on novel human-made plastic environments. As a PhD candidate in her research group, I am studying the fate and impact of nanoplastics on marine microbes. In the lab, I will selectively grow and isolate cultures of microbes that regularly interact with plastics, thereby expanding our Plastisphere microbial culture collection to include single-cell organisms other than bacteria, such as photosynthetic eukaryotes like diatoms, and heterotrophic protists such as ciliates. This allows us to determine whether different groups of microbes behave differently towards nanoplastics. I also assess whether microbes play a role in nanoplastic generation from larger plastic pieces.

Ecological impact on the base of the food web

Additionally, I will determine the ecological impact of nanoplastics on the base of the food web by running various ecotoxicological tests to better understand whether nanoplastics negatively affect microbes and if some microbes are better suited to co-exist with plastic debris than others.

Origin, structure and fate of nanoplastics

As a part of an NWO-funded consortium called ‘Nanoplastics: Origin, Structure, and Fate’, the Amaral-Zettler Research Group will provide the biological perspective as part of an interdisciplinary effort to better understand what nanoplastics are. We study the mechanisms of nanoplastic formation (origin), their chemical properties (structure), and what becomes of them once they enter the marine environment (fate).