April 24, 2019

Study Reveals the Susquehanna River Isn’t Immune to Microplastics


Microplastics are having a moment.

The public is becoming increasingly aware of the toll microplastics—particles less than 5mm in size—are taking on our environment. But it’s not just oceans that are vulnerable.

As senior ecology major Timothy Parks found in research he presented at Senior Scholars Day, the smallmouth bass in the Susquehanna River are also affected.

Senior Scholars Day provides an opportunity for students completing research, scholarly or creative projects—in topics ranging from art and business to science and music—to present the results of their work to the public. It is a tradition that has continued for more than 30 years at Susquehanna, and is currently supported by the Office of the Provost and the Career Development Center.

Parks dissected the stomachs of 67 smallmouth bass taken from the Susquehanna River in 2017 and 2018. Ninety-five percent of the 2018 smallmouth bass contained microplastics—up from 87 percent the previous year.

“We’re not exactly sure why there was such an increase,” Parks said. “The water flow was up in 2018, so that could have something to do with it.”

Parks collaborated on his research with Jonathan Niles, director of Susquehanna’s Freshwater Research Initiative; the state Fish and Boat Commission; and the state Department of Environmental Protection.

“Smallmouth bass are the top predators in these systems, so they are a good indicator of what the overall microplastic load is in the water body,” Parks said.

More than 200 students participated in this year’s Senior Scholars Day, which President Jonathan D. Green said is a testament to the students’ prolonged attention to their projects and the dedication of their collaborating professors.

Maybe Skip the Pine-Scented Candle

Dante’ Dobbins didn’t fully appreciate spiders until he began studying them.

“Now I understand how they live,” Dobbins said. “I’ve grown a love for them.”

Many spiders are associated with particular plants, Dobbins said. One species of long-jawed orb weaver prefers long grass while another prefers conifer trees. Crab spiders prefer blooming flowers.

Dobbins and biology Professor Matt Persons found strong differences in whether spiders are attracted to or repelled by certain plant oils. The citronella candle you light to repel mosquitos may attract some long-jawed orb weavers. Instead, consider a bouquet of goldenrod, which orb weavers avoided.

The same goes for pine.

“That pine-scented candle you light may give you the Christmas feeling,” Dobbins said. “But it could also attract spiders.”

You’ve been warned.