Marine Fisheries Research: Sarah Walters

Learn more about Sarah and her current research on spotted seatrout and redfish.

Sarah WaltersDegrees

B.S. Biology, Washington and Lee University, 2001
M.S. Biological Oceanography, University of South Florida, 2005


Immediately following college, I worked in the genetics group at FWRI in St. Petersburg for about a year. My project was to determine the influence of aquaculture on the Cedar Key hard clam population genetic structure. It was a great experience because the research was exciting and I worked with a fantastic group of biologists.

I left my FWRI job to intern at Mote Marine Laboratory because I wanted to gain experience at a different type of research institution before I had established a focused career direction. Plus, I grew up in Bradenton with Mote being a prominent force in our community. I even attended marine biology camp there as an 8th grader! I had an action-packed two month internship with the Center for Shark Research. I intended to stay for another four months but my dream job suddenly became available back at FWRI…

I love fish. Always have! When a position opened in the fish biology group at FWRI, I jumped at the chance to research spotted seatrout reproduction. I was fortunate to get the position and I've spent the past nine years working with a great team on spotted seatrout, snook, and recently, redfish.

What are you working on now?

Spotted seatrout
We are collaborating with our FWRI genetics group on a 3 year project in which DNA samples taken from a large residential spawning aggregation are matched against those taken from juveniles captured throughout Tampa Bay. Our goal is to determine the magnitude and distribution of this one large aggregation to the rest of the Tampa Bay population.

Our research has focused on three major aspects of spotted seatrout reproduction:

(1)   Where they spawn: to identify essential spawning habitats and required conditions

(2)   When they spawn (daily and seasonal): to determine spawning frequency

(3)   How much they spawn (fecundity): to calculate output and estimate sustainability

To address these questions, we have multiple projects that use different gears to gather the appropriate data. In order to determine life history parameters such as age and fecundity, we conduct traditional capture studies where we fish with nets and sacrifice the captured trout. Because trout males aggregate and produce sounds when they spawn, we are able to use underwater microphones to identify spawning habitat and associated parameters (such as depth, temperature, salinity). After we find spawning aggregations, we deploy specialized sound loggers that constantly record sound.  From these recorded spawning sounds, we can determine when the spawning season starts and ends, the duration of daily spawning, and if/how spawning is connected to tides and the lunar phase.

One of my favorite methods involves acoustic telemetry where we capture spawning trout and perform a little surgery to implant a transmitter in the abdomen of the fish. This transmitter sends out a signal that is detected by underwater receivers and we are able to get really interesting information about how often individual fish spawn. Ultimately, we are able to construct a comprehensive picture about the Tampa Bay trout population because we have studied these fish from multiple angles with a variety of complimentary techniques.

We know redfish form large spawning aggregations in offshore areas during the fall but have many questions associated with the spatial aspects of their reproduction and how it may impact population growth. A few of the questions include: assessing the number and distribution of spawning aggregations, locating the area(s) where these aggregations move to actually spawn, and determining if fish exhibit fidelity to certain spawning sites within the same spawning season and across years, We are using aerial surveys, passive acoustics, and acoustic telemetry to begin to tackle these key reproductive questions.

Was work in your current field your original career interest? Why or why not?

I grew up on the water and have always loved the Gulf and fishing but hadn't considered marine biology as a career until speaking with a friend's parents who are both marine biologists. It was senior year of college when I had a change of heart about pursuing medical school and began brainstorming alternative careers in science.  I was encouraged by their enthusiasm and I'll never be able to thank them enough for launching me on this path.

What would you say is your biggest accomplishment?

It's simple, but I think it would be feeling like I've found my spot in the world (at least for now!). I really enjoy my work and feel like I am also giving back to an environment that has given so much to me. When I participate in research that moves the field forward, it really is a great feeling and all those little moments add up.

What do you like most about your career?

Feeling like every day I am working on research that will hopefully benefit the fish, the ecosystem and the fishers of this cool little part of the world. I am lucky that my work is both intellectually and personally gratifying. I also am fortunate to work with a great group of people who all share the same enthusiasm and love for research-it's a great environment to be in.

What do you like least about your career?

Honestly, this question is taking some work to answer! It's a bit ugly to mention but the only drawback is the limited compensation. I doubt there has ever been a biologist who imagines they'll be making a large salary but it's a challenge to continually be fiscally creative!

What are some of your biggest challenges?

My biggest challenge is balancing the different aspects of the job, especially during the field season. When the fish are spawning, we are on the water a good bit and it's easy to shelf data analyses and writing. Typically, the winter provides time to focus on the laboratory and paper work but it really needs to happen all year- it is a work in progress for me to make that happen.

What advice would you give to someone interested in pursuing a career in your field?

Intern and/or get a summer job at a research lab to get a realistic idea of what the work involves. Spend time reading scientific literature and attend lectures to broaden your knowledge of the field. Take a scientific writing course. Take statistics courses. As an undergraduate, participate in professorial research and if provided the opportunity, present research at conferences/meetings and coauthor a paper. Those actions would make you competitive right out of school.

These days it is pretty much a given that graduate school needs to eventually be part of your plan. My supervisor gave me the following advice that I found helpful: decide what your professional goals are immediately, in 5 years and in 10 years to try and help you decide what degree is appropriate.

Once you've found that great job, make sure that you find a great mentor. I am fortunate that my supervisor happens to be that person for me. Having someone who is willing to teach, challenge and support you insures that your work and thought processes are constantly evolving and resulting in solid research. Plus, it does wonders for your overall happiness!

FWC Facts:
Seagrasses stabilize the sea bottom with their roots and rhizomes (underground stems) in much the same way that land grasses retard soil erosion.

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