Micro- and Nanoplastics Exposure and Effects on Embryonic Development and Larval Behavior of Zebrafish

Hawai'i and other island communities around the globe are experiencing high exposures to micro- and nanoplastics (MNPs). Widespread use of various types of plastics and the action of wave physics coupled with abundant silica creates a constant production of MNPs. The community health effects of exposure to MNPs are not yet fully understood. The aquatic vertebrate model zebrafish, Danio rerio, was utilized to evaluate the developmental and behavioral effects of nanoplastic (NP) exposure as well as visual confirmation of plastic accumulation after embryonic and larval exposure. Eye and yolk size, heart rate, angle of development, and early larval locomotion behavior were quantified after early NP exposure lasting 3 or 5 days. In this work, a digital laboratory environment is used as the context for research trainees spanning high school to graduate and medical school in Hawai'i to explore health outcomes of developmental NP exposures. Presence of MNPs in the early developmental environment led to changes in growth and behavior of exposed fish. Data analysis showed significant effects of exposures on changes in the rate of development and yolk consumption on day 2 and reduced body length and increased locomotion on day 6. Nanoplastic exposure also affected overall body length, but this effect was not significant. These data support the potential dangers of MNP exposure and demonstrate their persistent detrimental effects on development and behavior in young zebrafish. Accordingly, our work contributes toward shifting focus toward understanding longer impacts on health, growth, and behaviors and potentially the reduction of harm in developing vertebrates.