TFUI is excited to showcase Samantha Leigh for this "Behind the Fins" post. As a PhD student, she is interested in "how marine organisms acquire energy based on their specified digestive strategies" -- something we have not yet discussed here! Specifically, Samantha wants to know how environmental changes impact the ability of marine organisms to specialize on low-quality food sources.
How neat is that?! And how is that information important to the general public? Read on and find out (plus, if you want to see more pictures of cute bonnethead sharks, you definitely want to read this bio!).
P.S. Remember that The Fins United Initiative has done a bio on bonnethead sharks before! You can read it here.
The Fins United Initiative: First, a big thank you for being here with TFUI. So! Let's dive in: why did you choose marine biology as your career path?
Samantha Leigh: I have always been fascinated by the ocean. It makes up the majority of our earth and yet, there is still so much that we do not understand about it! As a high school student, I started volunteering at the National Aquarium in Baltimore where I got to interact with marine biologists and learn about a variety of different animals and ecosystems. I decided then that I wanted to pursue marine biology as a career, but I didn't know exactly how. As a high school senior, I was required to complete a senior project. For this project, I worked in an immunology lab at the University of Maryland where they were using nurse sharks as their model organism to study viruses. This made me realize that I wanted to pursue a career focused on shark research. Sharks are literally the biggest fish in the ocean and we are still learning new things about them everyday! I went on to earn my bachelor's degree in marine science from Coastal Carolina University before pursuing my PhD at the University of California-Irvine (UCI).
TFUI: What are you currently studying right now at UCI?
SL: My current research at UCI focuses on the digestive physiology of bonnethead sharks. The bonnethead shark is the only shark species known to consume large amounts of seagrass material in its diet (Bethea et al. 2007; Bethea et al. 2011). My research aims to determine a) how much of this seagrass material bonnetheads can actually digest and use as a nutritional resource, b) how bonnetheads are capable of processing such a large amount of plant material with a digestive system that looks identical to other closely related strictly carnivorous sharks, and c) what ecological role the bonnethead shark is actually playing in crucial seagrass meadow habitats if they are not acting like the carnivorous predators that they were originally thought to be.
TFUI: Oh my goodness, I love bonnetheads! Now, your research revolves around the digestive physiology, ecology, and evolution of sharks and other fishes. Can you explain to the TFUI audience what exactly that all means?
SL: This means that I am interested in how sharks acquire nutrients and energy from the different food items that they eat. Sharks consume a huge variety of different food items ranging from marine mammals, thousands of different species of fish, mollusks, crustaceans, zooplankton, and more! On a physiological (or individual organism) level, I want to know how their digestive systems work differently to process the different types of food that they eat. On an ecological level, I want to know how the food that sharks eat influences their role in the ecosystems that they inhabit around the world. On an evolutionary level, I want to understand how different shark species have evolved over time to digest their prey items with optimal efficiency.
TFUI: That's a lot of levels! And why, in your view, is your work so important?
SL: Since the majority of sharks are considered to be top predators, they are at the top of the food chain. This means that they control the biodiversity of many of the fish species that us humans depend on for food and economic resources. This is why it is so important for us to understand what sharks are consuming, how they process that food, and what they are excreting into their habitats around the world. This information helps us to create effective shark conservation and fisheries management policies so that we can ensure sustainable fishing practices for generations to come.
TFUI: So why does the general public need to know about the digestive physiology of sharks and other fishes? How does the general public benefit from that?
SL: To put into perspective how much we rely on healthy ocean ecosystems, the fishing industries provide over 3 billion people worldwide with their primary source of nutrition! Without understanding how sharks play a role in these ecosystems, we won't be able to protect them. Unfortunately, shark populations are declining, which means that ocean ecosystems around the world will suffer unless we can research ways to conserve them.
TFUI: What has been your toughest experience out on the field or lab?
SL: Field work is always unpredictable!
TFUI: Ha, don't we know it!
SL: There have been days that I have gone out on the water to find bonnethead sharks, only to leave empty handed. This is always disheartening because it is a lot of work and money to organize a boat and crew for an entire day! However, the days when we do find sharks always makes the tough days worth it.
TFUI: Do you think people in your country have a good relationship with the ocean environment?
SL: In general, I think that most people have a good relationship with the ocean. However, I think a lot of people don't realize how much their daily activities can influence ocean health. Littering, using one-use plastics, not recycling or recycling incorrectly, eating unsustainable seafood, etc. can all negatively impact the ocean.
TFUI: What about their relationship with sharks?
SL: For sharks specifically, I've met people who absolutely love sharks and others who are absolutely terrified of them. Luckily, there is so much information available now about how rare negative shark encounters are. The vast majority of shark encounters occur without any injury to humans. The more that scientists can learn about sharks, the more equipped we will be to ease the minds of worried beach-goers.
TFUI: What has your PhD experience taught you about yourself, your career path and, ultimately, the sharks?
SL: Through my PhD experience, I've learned that having grit is an important quality when pursing a science career. It is quite common to have an experiment fail, or to have a grant rejected. I've learned to view these "failures" as learning experiences so that I can keep improving. This is something that will be important throughout my career, not just as a PhD student. My PhD experience has also opened my eyes to how much we still do not know about sharks! I have so many questions that I'm excited to answer throughout the rest of my career.
TFUI: Speaking of your career, what’s your dream research project?
SL: My dream research project would involve comparing different populations of bonnethead sharks throughout their distribution ranges. Currently, I've only studied bonnetheads in the Florida Keys, and I'd really like to see if bonnetheads in other locations are capable of the similar digestive efficiencies when it comes to consuming plant material. I'd also love to compare the bonnethead shark to other closely related species in different habitats around the world.
TFUI: And what would you say is the most rewarding thing about your job?
SL: I love getting to share my findings with the public! I am always so excited when I learn something new about sharks and I love getting to pass this information on to others.
TFUI: What’s next in store for you?
SL: I am planning to graduate with my PhD in the spring of 2019. My ultimate goal is to become a professor at a university so that I can continue my shark research as well as educate the next generation of marine scientists.
TFUI: Do you have any advice for those hoping to follow in your sharky footsteps?
SL: My advice would be to gain as much experience as possible, both in the lab and in the field. Even if the work is not directly related to the topic that you want to study longterm, working in a research environment in general will help you to grow many important skills! For example, my first job after I graduated with my bachelor's degree was working in a water quality research lab...having absolutely nothing to do with sharks! However, I learned so many important lab and field techniques that I still use everyday studying sharks.
TFUI: What great advice-- thanks for sharing!
THE FINS UNITED INITIATIVE WOULD LIKE TO THANK samantha FOR HER TIME AND
TFUI Founder Melissa C. Marquez is author of all animal bios and "Behind the Fins" segments.
SEE MELISSA'S TEDx TALK HERE:
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