URBAN Trainee Caroline Fleming Studies Urban Corals Under Stressors

Watch Video: URBAN Trainee Caroline Fleming Studies Urban Corals Under Stressors

Caroline Fleming is a PhD Student in the Department of Biology in the BU Graduate School of Arts & Sciences and the BU URBAN Program. She received a 2021 Early Stage Urban Research Award from the Initiative on Cities (IOC) for her project, “Stress in the City: Examining Metabolic Consequences of Toxicological Exposures in Resilient Urban Corals Under Global Change Stressors.”

Read the Q&A with Fleming and watch the video by IOC and URBAN to learn more about her research on urban corals facing environmental stressors.

Amelia Murray-Cooper (IOC): Why were you interested in working on this project?

Caroline Fleming: Temperate corals receive a lot less attention than tropical corals, but they exist in urban waterways. They are important ecosystem indicators for shellfish species, which occur in the same places as urban corals and might potentially be consumed by humans. They are also ecological indicators of general ecosystem health because they’re an important part of the benthic community at the bottom of the ocean.

Urban environmental challenges are biased by the fact that humans are terrestrial species. Relatively little attention gets paid to urban waterways, urban harbors, and the ecological effects of what we do on land. I was particularly interested in wastewater treatment plants and urbanization because it’s a connection of the land and sea. We are living in a time of global change, specifically in the northwestern Atlantic ocean, where we are experiencing higher rates of ocean warming than a lot of other places in the world.

What are the main takeaways from your findings?

I haven’t crunched the data yet, but going into this, we knew that corals exist in urban environments like the New York Harbor. In a publication from my Co-PI Randi Rotjan, the researchers found that the coral preferentially ate microplastics over its own food, so we know that microplastics and ecotoxicological exposures are a real issue in urban harbors. We’ve also been doing some pilot data on caffeine toxicity. It seems like the caffeine toxicity reaction from larvae is different, but we’re worried that larvae in particular might be more susceptible because they’re babies.

Did anything surprise you during your research?

I was surprised by how persistent microplastics are in the environment as well as how poorly wastewater treatment plants are able to filter waste. A lot of my research is trying to understand exactly the scale of the problem so we can tackle the problem in an appropriate way. The resiliency of the corals has surprised me because these corals are living in New York Harbor, which means they are living in mixtures of various chemicals. That’s something we’re doing next summer to find out exactly how well they’re doing, but we do know they exist there, which is pretty surprising in and of itself.

What do you hope comes out of this work?

I really hope there’s an emphasis on marine urban organisms and their potential vulnerability on top of the existing vulnerabilities of climate change. I think it would be really cool to see the coral that we’re working with become an indicator species for pharmaceuticals and other toxicants in urban harbors. It may be hard to track down a certain species to understand how well it’s doing, but Astrangia poculata corals are really easy to pluck off a rock, so they might be a good indicator species.

I’m also hoping to get a sense of the vulnerability of different life stages of the coral. I’m hoping to understand if the eggs or larvae of the coral are particularly vulnerable, and if certain measures, such as wastewater filtering systems, need to be put in place to protect those specific life stages. They only spawn for a certain amount of time during the year, so maybe there needs to be a moratorium on some kind of chemical during that portion of the year.

I’m also hoping to understand how the stressors of ecotoxicological pollutants in urban areas and climate change affect the available energy of the organism and its resilience to wounding stress, wave stress, or other trauma it might endure. If you already have a weakened coral because it’s been exposed to global change and ecotoxicity, if something else happens, is that coral going to survive? I’m also interested to see exactly what pollutants there are in the New York Harbor in the areas where we know Astrangia exists and the proximity to the point sources of those toxicants.

The IOC has funded over 70 projects to date through the Early State Urban Research Awards. Learn about past projects and learn how to apply for future funding opportunities here.