Picture above: SoMAS PhD student Lisa Crawford, fishing for sharks! Photo by Charles Witek.
We caught up with Stony Brook University Graduate Student Lisa Crawford during a busy summer field season, and she shared some of her summer adventures with us.
Who are you?
My name is Lisa Crawford. I am starting the fourth year of my PhD at SoMAS studying ecotoxicology.
How are you spending your summer?
This summer I have been out in the field fishing for local North Atlantic sharks such as makos, threshers, sandbars, sand tigers, duskys, and blues. In addition I will be participating in several shark tagging expeditions to collect samples for my research. I have the wonderful privilege of participating in two expeditions with the non-profit group OCEARCH as a collaborating scientist. We are going to Nantucket and Nova Scotia with the hope of sampling large white sharks. Fellow SoMAS student, Oliver Shipley, and I will also be participating in a multi-institution shark tagging expedition with the Fisheries Research Foundation in order to tag and sample local species. Last week I was at the American Elasmobranch Society conference in Snowbird, Utah learning about the latest research in the realm of sharks, skates, and rays. It’s quite a sharky summer!
Why is your research important? How does your work/research help advance scientific knowledge?
I study the potential impacts of human derived contaminants like mercury and PCBs on sharks in the Atlantic Ocean. Sharks are exposed to contaminants through their diets. Contaminants diffuse into plankton with are then eaten by fish which are then eaten by sharks. The higher an animal like a shark feeds in the food chain, the greater the amount of contaminants the animals consumes each meal—this is called biomagnification. Many human-derived contaminants cannot be easily excreted or detoxified by the body and so sharks are also at risk of what we call bioaccumulation of contaminants in their tissues and blood.
My team and I catch sharks offshore, take non-lethal blood and muscle samples to analyze for contaminants, and then release the sharks. We also take tissue samples to extract RNA—the single stranded version of DNA that passes messages along to cells to make proteins. We look for genetic messages that are known to be associated with detoxification or stress response to contaminants. By integrating chemistry and molecular methods, I can get an idea of which contaminants the shark has been exposed to and at what concentrations and how the shark’s body is responding to exposure at a cellular level.
I hope to understand how sharks are potentially being impacted by the accumulation of contaminants in their bodies. Combining this knowledge with ongoing research of shark movements, behavior, and ecology, we can better identify adverse outcomes of contaminant bioaccumulation such as reduced reproductive ability or even shorter lifespans.
What made you choose this career path?
I grew up in Colorado, a land-locked state. I was always fascinated by the ocean growing up, so as I went through school and learned that I could make a career out of my passion, I knew I needed to pursue a degree in marine biology. When I was an undergraduate at New College of Florida, I studied sensory biology of sharks. I became fascinated by shark biology and the big unanswered questions surrounding sharks, which was what led to me to continue my shark research at SoMAS—this time focusing on shark ecotoxicology.
What is your favorite sea creature and why?
My favorite sea creature is the short fin mako. It was the first shark species I worked with up close and had a chance to sample for my own research.
What message do you have for anyone considering a career in marine sciences?
Marine science is an enormous discipline that encompasses a massive range of topics and job types. No matter your skill set or education, follow your passion, because there are creative ways to have a career in marine science. From coming out on the boat and catching sharks, to analyzing massive fisheries data sets, to studying parasites under the microscope, all the way to teaching the public about the ocean, there are so many ways to have a career in marine science. The best piece of advice I can give is to be persistent and make connections in the marine science world. Read the current literature, reach out to your favorite scientists, and consider attending a marine science conference. There is a place for everyone in marine science!