The World is Her Oyster

USD alumna Grace Cawley smiles alongside a jar of photoplankton


As kids, most of us had a particular dream job we imagined for our grown-up selves. Grace Cawley ’19 (BA) wanted to be a marine biologist. “Whales were something that interested me,” she jests. “But do kids understand what it means to be a marine biologist?”

Years later, she’s actualized that dream and is studying and working as a PhD biological oceanographer at the Scripps Institution of Oceanography in La Jolla. It’s a title, she says, that she feels she is slowly earning.

Cawley grew up in Salem, Massachusetts, or as she is typically reminded, the place where the witch trials were held. Her dad was a big advocate of exploring the outdoors, something the family frequently did together.

During the summers, Cawley and her family would go to Cape Cod. There, she and the other children would play in the tide pools, creating minnow houses and looking for life under rocks.

Still, when it came time to apply to colleges, she wasn’t thinking about things aquatic. She tossed around ideas for majors such as educational psychology and pre-med. She originally applied only to East Coast schools. It wasn’t until a high school friend visited the University of San Diego that she added it to her list.

“My brother is two years older than me and went to the University of Miami,” recalls Cawley. “He was always outside and always at the beach. I remember thinking, ‘That must be so freeing.’” When her parents pressed her for a decision, she answered, “USD,” even though she hadn’t even visited campus. 

It was an impulsive decision, but one that she says paid off.

As a first year, Cawley still believed she would declare as pre-med and thought she’d select a chemistry class for her Living Learning Communities requirement. Instead, she ended up in Introduction to Earth Systems, taught by Associate Professor of Environmental and Ocean Sciences Beth O’Shea, PhD.

The class became a defining moment for Cawley. 

She quickly dropped the idea of pre-med and began to pour her heart and soul into environmental and ocean sciences. O’Shea also became her advisor.

By her sophomore year, Cawley was approached by Associate Professor of Environmental and Ocean Sciences Jennifer Prairie, PhD, to work on a research project, a rare opportunity for a sophomore.

“She talked about how she studied marine snow and there was this new project focusing on how zooplankton interacts with it,” says Cawley.

To make the deal even more appealing, during her senior year, Prairie pitched the idea that Cawley become one of the very first students to participate in the department’s combined degree program. By the end of her studies, she would earn both a BA and an MS, all while expanding on her research project.

Cawley agreed and began to research the effect of phytoplankton properties on the ingestion of marine snow by Calanus pacificus. 

Let’s break that down.

The ocean is a balanced ecosystem. Live phytoplankton live in the topmost 200 meters of the ocean or the surface ocean. These microorganisms are similar to plants on Earth, in that they contain chlorophyll and require sunlight to live and grow. They also pull carbon from the atmosphere above.

Phytoplankton have a sticky outer coating. When they collide, they form clumps called marine snow, due to the fact that they actually look like snow falling in the ocean.  Because the phytoplankton weigh each other down in these clumps, they leave the surface ocean and go into the deep ocean, taking the carbon with it.

Originally, biological oceanographers thought the snow particles would just sink, ending the cycle of the marine carbon pump, where carbon is drawn out of the atmosphere and down to the ocean floor.

But Cawley noticed phytoplankton, even as a snow particle, still served as food for zooplankton. The zooplankton would eat it, then excrete it. This added a “wrinkle to the question of the role of marine snow in the oceanic carbon pump.”

Cawley, along with co-authors Moira Décima, Andrea Mast and Jennifer Prairie, published their findings in the Journal of Plankton Research in Fall 2021.

In January, Cawley was awarded the 2022 Cushing Prize from the journal for the best article written by an early career stage scientist. 

She attributes her success thus far to the women who’ve uplifted her.

“I was blessed to find Jennifer and Beth — two women in a field I wanted to be in — and learn from their journeys. I didn’t always have a 4.0, but I found my place in research and did it well enough that people gave me chances.”

She’ll continue working on ocean research for her PhD for the next several years. After that, the world is her oyster. Looking back, Cawley finds it hard to believe that she ever considered the idea of any other major.

“I was looking for a challenge, and research is a challenge I can do on my own terms. I really enjoy that.”

She has advice for young women doubting if research is the path for them. “Hold your space. We lose ourselves to imposter syndrome. Fail and make mistakes, but don’t let them define you. Grow from them.” 

Leave a Reply

Your email address will not be published. Required fields are marked *