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By Diana Kenney

A theme of human impacts on coastal environments dominated the undergraduate research symposium on Dec. 17 presented by the Semester in Environmental Science (SES) program, which is entering its 25^th year at MBL.

Longtime SES Director Ken Foreman, who is retiring this year, introduced the symposium for his final time. Beginning in fall 2022, Foreman’s successor in leading the program is MBL Associate Scientist Mirta Teichberg,

“It has been a privilege to meet so many committed, bright and enthusiastic students from colleges and universities throughout the nation during my tenure as SES director, and to follow the meaningful contributions in research and policy they have made as they moved forward in their careers,” Foreman said.  “I like to think the experience students get in the SES has contributed to their success!”

С�����Ƶ scientist Ken Foreman has directed the Semester in Environmental Science program since 2004. SES was founded in 1997 with С�����Ƶ scientist Jerry Melillo as director and Foreman as associate director. Photo courtesy of Ken Foreman

Here are a few highlights from the symposium, which was videorecorded (�����Ի�������������DzԲ�):

Friends Award

Student Ella Lemely-Fry (Lawrence University) received the “Friends Award” for excellence in her symposium presentation. For her SES research project, Lemely-Fry used novel fluorescent imaging techniques to explore the association of soil minerals with organic matter, considering implications for carbon storage and nutrient cycling. This award is bestowed annually by the Friends of the MBL.

Coral and Microplastics

In a great show of teamwork, three SES students dove into how tiny fragments of plastic waste (microplastics) impact the local coral species, the Northern star coral (Astrangia poculata).

Nora O’Keefe (Trinity College) measured the abundance and composition of microplastics found in Cape Cod corals and neighboring environments. She gathered her coral samples with the help of С�����Ƶ scientists Loretta Roberson and Anne Giblin, who dove for deeper-water corals off Woods Hole.

С�����Ƶ scientists Anne Giblin (left) and Loretta Roberson dove in Woods Hole's Great Harbor to collect sediment and coral samples for SES projects. Credit: Daniel Cojanu/Undercurrent Productions

Using tweezers, Alice Ball (Connecticut College) fed both plastic fragments and brine shrimp to coral polyps, and videotaped them eating. She was exploring feeding preferences in coral and how they responded to microplastics.

“Some of the coral polyps really liked plastic,” Ball reported – she even captured footage of polyps trying to steal plastic from each other. Fortunately, she found the coral ingested more brine shrimp overall than plastic. However, the corals still ingested a large amount of plastic -- in some cases, more than 50 particles per hour per polyp.

“Eating microplastics can be an energy intensive activity,” Ball said, since the coral gains no nutrition in the process of both ingesting and egesting the plastic. Her study hints at the enormity of the microplastics problem in marine environments.

Ball’s research co-advisors with Roberson, С�����Ƶ scientists Rut Pedrosa Pàmies and Javier Lloret, have been tracking microplastics in local ecosystems for several years. Prior SES students have contributed to this research as well.

The local coral Astrangia poculata ingesting a plastic fiber (white strand sticking out of the polyp's mouth). Credit: Alice Ball and Sydney Russo, SES 2021

To ask if microplastics cause physiological stress in coral, Sydney Russo (Clarkson University) studied the physiological activity of the coral holobiont, both with and without plastic exposure. She found no long-term significant difference in photosynthesis rates, but did find a difference in respiration rates, again indicating that microplastics may have energetic costs for coral.

An Impressive Output

Other SES students traced the footprints of various agents – plastics, lead, mercury, sewerage, nitrogen, methane – in Cape Cod and Plum Island ecosystems, assessing impacts in ponds, marshes, estuaries, and on marine animals and vegetation.

MBL Education Director Linda Hyman congratulated all the students for their research contributions and hard work. “You have been an amazing group. What challenging times we live in, and you came here and made us all proud -- of your research, your professionalism, your comportment,” she said.

Screenshot of SES student James Hu (University of Chicago) presenting his research on sourcing anthropogenic lead pollution at Plum Island in northern Massachusetts.

“As you leave the Woods Hole community, know that you will always be a member of our family,” Hyman said. “There are so many ways you can come back. I hope you will consider making the MBL a part of your academic life forever. We're here for you!”