Marine biology student studying fish to tackle Gulf Coast issues

When Antrelle Clark first started her studies in marine biology, the last thing in the world she wanted to study was fish. Now, she’s studying how urbanization along the Gulf Coast is impacting one fish in particular: the killifish. 

Clark, who is working towards her Ph.D. in marine biology from the College of Sciences and Mathematics, is a graduate research assistant at the Fish Ecology and Evolution Lab, led by Assistant Professor Moisés A. Bernal. Along with her colleagues, she studies the biological mechanisms behind how fish respond to shifts in environmental factors. 

Not only are killifish vital intermediary species in the food chain, eating both algae and smaller fish and serving as bait for larger ones, but, according to Clark, they are also a good measure of environmental health due to their ability to withstand extreme climate fluctuations. 

Clark's data indicates killifish in these urban sites experience much more fluctuation in their environment and stressors than those in the reference sites do.

“Because they’re so hardy, they can be a good bioindicator for any environment,” Clark said. “If you see these fish start to be impacted by their environment, that’s an early indicator the ecosystem isn’t stable.” 

Measuring human impact 

The Gulf Coast region is becoming increasingly urbanized to address population and tourism needs. This rapid development taking place along the Gulf comes with a rise in impervious surfaces, or surfaces that do not absorb water.  

“When it rains, these impervious surfaces don’t retain that rainwater, so it just washes off into coastal ecosystems,” Clark said. “These ecosystems naturally fluctuate already due to the tide coming in and other environmental factors, but those fluctuations are accentuated by the freshwater running off into the ecosystem.” 

Clark’s research involves studying four different populations of killifish: two in reference sites, or sites that are not in urbanized areas, and two in urban areas. Her data indicates killifish in these urban sites experience much more fluctuation in their environment and stressors than those in the reference sites do.

“My hope is that my research will raise awareness of how the species in these ecosystems are impacted by our actions,” Clark said. “Are they going to be able to survive these changes in conditions, or are they going to have to migrate somewhere else? What does that mean for other species that inhabit the ecosystem?” 

Interdisciplinary perspective 

Clark is a member of the NSF Research Traineeship (NRT) at Auburn, a program that encourages scholars from across fields to collaborate on projects related to climate resilience.

As a result of the NRT, Clark accompanied Anderson on a trip to the Mobile-Tensaw River Delta, where she was able to not only study killifish, but also learn more about wetland function and ecology.

 Through the program, Clark met Andrew Balder, a graduate student working in the lab of Bernal’s longtime collaborator, Professor Chris Anderson of the College of Forestry, Wildlife and Environment. 

As a result of the NRT, Clark accompanied Balder and Anderson on a trip to the Mobile-Tensaw River Delta, where she was able to not only study killifish, but also learn more about wetland function and ecology. 

“Our disciplines have a lot of overlap, but I see it as approaching the same question in different ways,” Clark said. “Learning from each other can help us arrive at those answers.”

Clark also received external grant support to conduct research abroad, allowing her to study in both Israel and Sweden. 

“Like the interdisciplinary work I do at Auburn, studying abroad is all about learning from and teaching each other,” she said. “That trade-off has been so informative to my research.” 

Looking forward 

Clark said the mentorship she’s received throughout her time in graduate school is one of the big motivators that has kept her going.

“Dr. Bernal's support means everything to me,” she said. “He’s more than just my academic mentor. He’s my mentor in general as I navigate the difficulties of adulthood while attending grad school.” 

Prior to Bernal’s lab, Clark was inclined to avoid anything “molecular, genomic or related to fish.” Now, she has a passion for using molecular and genomic techniques to understand how changes in the environment are impacting killifish. 

Following her graduation, Clark hopes to move to the Great Lakes region and apply her studies to freshwater killifish. 

“My research so far has been focused on coastlines getting fresher and how saltwater killifish respond to it,” she said. “In the Great Lakes region, the same thing is happening in reverse, as the salt solutions used to ice roads are running off into these freshwater lakes and increasing salinity.” 

Clark credits her time as an NRT trainee with helping her discover her career ambitions. 

“One of the best things to come out of the NRT was how it exposed me to jobs I didn’t know existed,” she said. “That focus on interdisciplinary research and climate resilience is something I want to carry with me after my time here.”