MEDDLING MICROPLASTICS: A Study of the Interactions Between Microalgae and Microplastics
By Margaret Krawciw
Senior Category (Grades 11-12)
Experiment | Environment

Despite the constantly increasing prevalence of microplastics in all bodies of water, a comprehensive understanding of how microplastics affect microalgae is still largely unknown. This project studied microplastics found along Victoria’s coastline and how two species of microalgae would respond to selected microparticles. Two marine algae, Nannochloropsis oculata (non-motile) and Tetraselmis chui (motile) were exposed to 0.1g-0.4g HDPE, 0.2g-0.4g of PVC and 0.3g sawdust. Growth curves were measured and the correlation between microplastic levels and growth rates was determined. When T. chui was exposed to HDPE, it was observed to bind to the fibres and multiplied at a faster rate than the control. The higher the amount of HDPE, the more multiplication that occurred. The increase in growth rate was almost proportional to the amount of introduced HDPE. The PVC inhibited the growth of the T. chui. This is probably due to the toxicity of PVC additives such as plasticizers and heat stabilizers.
