Researchers link microplastics pollution to algal blooms

Drs. Kashian and Gopalakrishnan in the lab
Drs. Kashian (front) and Gopalakrishnan (rear).

Drs. Kashian and Gopalakrishnan discover that plastic pollution alters algal growth

Over 10,000 metric tons of plastic enter the Great Lakes annually. The impact of plastic on the aquatic ecosystem is a growing concern.

Our understanding of the relationship between algae and microplastics in the Great Lakes has been significantly advanced by research done in the Department of Biological Sciences. A team, led by Professor Donna Kashian and Dr. Kishore Gopalakrishnan, has discovered a reciprocal relationship between microplastics and algae that has implications for the health of the Great Lakes ecosystem.

Their research revealed that some algae increase the production of extracellular polymeric substances (EPS) when exposed to microplastics. EPS are complex polymers that play an essential role in the formation of biofilms. Biofilms are communities of microorganisms that adhere to surfaces, such as boulders or even other organisms.

The increase in EPS production can contribute to harmful algal blooms (HABs) caused by the rapid proliferation of algae. Blooms can have harmful effects on aquatic ecosystems, including the production of toxins that can be harmful to fish and contaminate water supplies.

The issue becomes even more serious when microplastics are covered with algae, as they can be mistaken for food by aquatic organisms. The new study showed that microplastics and algae interact in a complex way. One unexpected finding was that floating microplastics will actually sink to the bottom of a container when covered with algae.

This is significant because it expands the penetration of microplastics in the aquatic environment. These findings illuminate the complex interaction between microplastics and algae in the Great Lakes ecosystem and emphasize the need for continued research on the impact of microplastics, as well as the development of effective mitigation strategies.

You can listen to a discussion of this research on Michigan Radio and learn about research in the Kashian lab.

← Back to listing