The Effect of Microplastic (MP) Shape on Adsorption and Physiological Responses of Duckweed (Lemna minor)

School Name

Spring Valley High School

Grade Level

10th Grade

Presentation Topic

Environmental Science

Presentation Type

Non-Mentored

Abstract

Microplastic (MP) pollution has become a significant ecological concern, yet limited research has examined how differences in particle shape influence their interactions with plants in freshwater environments. This study investigated the effect of polyethylene microplastic shape (beads, fibers, and fragments) on frond growth, root growth, and MP adsorption in Lemna minor. It was hypothesized that irregularly shaped fragments would produce greater negative impacts on growth and higher adsorption than beads and fibers due to their morphology and mechanical interference. A 14-day freshwater experiment was conducted using 120 replicates (30 per treatment), each containing 50 mg L-1 of MPs and 10-20 fronds. Frond length, root length, and MP mass adsorbed per frond were measured on days 0, 7, and 14. One-way ANOVAs at an alpha level of 0.05 were used to determine whether MP shape produced statistically significant effects on each dependent variable. Microplastic shape had no significant effect on frond growth (F(3,36) = 0.07, p = .977) and no significant effect on adsorption (F(3,36) = 2.83, p = .052). However, MP shape had a statistically significant effect on root growth (F(3,36) = 13.50, p < 0.001), with fragments causing the greatest mean root length reduction. Adsorption increased over time for all MP shapes, and fragments produced the greatest adsorption, though these differences were not significant. Overall, the findings indicate that MP shape plays an important role in determining ecological impacts, especially on root development, and should be incorporated into future microplastic research.

Location

Furman Hall 208

Start Date

3-28-2026 9:45 AM

Presentation Format

Oral and Written

Group Project

No

COinS
 
Mar 28th, 9:45 AM

The Effect of Microplastic (MP) Shape on Adsorption and Physiological Responses of Duckweed (Lemna minor)

Furman Hall 208

Microplastic (MP) pollution has become a significant ecological concern, yet limited research has examined how differences in particle shape influence their interactions with plants in freshwater environments. This study investigated the effect of polyethylene microplastic shape (beads, fibers, and fragments) on frond growth, root growth, and MP adsorption in Lemna minor. It was hypothesized that irregularly shaped fragments would produce greater negative impacts on growth and higher adsorption than beads and fibers due to their morphology and mechanical interference. A 14-day freshwater experiment was conducted using 120 replicates (30 per treatment), each containing 50 mg L-1 of MPs and 10-20 fronds. Frond length, root length, and MP mass adsorbed per frond were measured on days 0, 7, and 14. One-way ANOVAs at an alpha level of 0.05 were used to determine whether MP shape produced statistically significant effects on each dependent variable. Microplastic shape had no significant effect on frond growth (F(3,36) = 0.07, p = .977) and no significant effect on adsorption (F(3,36) = 2.83, p = .052). However, MP shape had a statistically significant effect on root growth (F(3,36) = 13.50, p < 0.001), with fragments causing the greatest mean root length reduction. Adsorption increased over time for all MP shapes, and fragments produced the greatest adsorption, though these differences were not significant. Overall, the findings indicate that MP shape plays an important role in determining ecological impacts, especially on root development, and should be incorporated into future microplastic research.