From the Lab to the Sea: The Work of Fisheries Scientists 

Katrina Zarrella Smith

Fishing is a big part of life in the coastal towns of Massachusetts; even all the way out here in Amherst we see the benefits that being a coastal state has. But we don’t want to take our access to coastlines and fresh fish for granted. In our quickly warming climate, ecosystems are fluctuating rapidly and fish populations are feeling the effects.  

This is definitely on the mind of fisheries researchers such as Katrina Zarrella Smith, a PhD candidate in the Organismic and Evolutionary Biology Program (OEB) here at UMass. The ocean and fishing have never been foreign to her - growing up she spent her summers in a fish shack on a salt marsh up in Maine. In high school, she volunteered at the New England Aquarium in Boston and proceeded to do her undergraduate work at College of the Atlantic in Bar Harbor, Maine. While there, she got the opportunity to study marine ecology and work at sites on both coasts of the United States as well as the coast of Mexico. After undergrad, she began working on data management but she realized she wasn’t quite done with the aquatic world yet and came to UMass to pursue a PhD with advisor Dr. Adrian Jordaan, where she has put her knowledge of ocean ecology and data science to excellent use. 

Currently, Zarrella Smith is working in Boston Harbor researching winter flounder populations, a species in the group of fishes known as New England groundfish. Groundfish are an important part of cultural history in the northeast. They make up a big portion of our fished population historically and we can still see the effects of this long history of fishing groundfish today. Populations subjected to historical overfishing are still in the process of recovering. In the case of winter flounder, the population peaked in the 1980s and has been on decline since. The reason? Zarrella Smith says we don’t entirely know why. A lot of the issues that researchers had assumed to be the problem, such as overfishing and poor water quality, are improving, but the population just isn’t showing as encouraging signs of recovery as expected. To try and figure out what is going on, Zarrella Smith’s research has her spending her time “filling data gaps” in our understanding of this species’ behavior, ecology, and population dynamics.  

This more often than not looks like an early morning starting off a 16-hour day out in Boston Harbor. Zarrella Smith captains her own fishing vessel, which doubles as her research vessel, meaning she is playing the dual role of lead researcher while making sure everything is ship-shape. Some days this work is done with just her and her first mate, other days she is captaining a larger crew. It's not uncommon for her to work with UMass undergraduates interested in this line of work. When Zarrella Smith’s crew is out on the water, they are doing everything from trawling surveys - a term for catching fish in large trailing nets - in order to do fish counts, to gathering habitat information in the form of salinity levels, water temperatures, and what the structure of the environment is like. The information that she gathers is added to a large database of measurements that will span three years. This lets researchers like Zarrella Smith compare fish populations to fluctuations in salinity or temperatures and see if there could be relationships in what makes a species flourish or flounder.   

It’s a lot of information to sift through, and all this data being generated means that the data management side is equally as important as the field work. And sifting through it is also part of Zarrella Smith’s job. On days when she isn’t out on the water, she can be found working in front of her computer compiling data and working on coding programs, often for just as long as she would be out fishing. Her work is decidedly one with two very different skill sets and she often finds herself having to be a jack of all trades in this line of work. Zarrella Smith says, “you need to understand how your boat engine works, or what you need to do to get out of a snagged net, or what you need to do when your coding fails. The breadth of the skills this job entails is almost never-ending.” 

The field is also changing, says Zarrella Smith, as we are seeing a shift into really promising methods of modeling that involve ecosystem-based management rather than just looking at a single species. This means researchers are not just measuring population levels for a single species separate from different ecological factors. Instead, they are looking more at interactions between multiple species of fish, their environment, and the effects of human’s interaction with the species to try and get clues on why populations are changing. 

But this transition from looking at a single species to an entire ecosystem is a slow process, Zarrella Smith cautions. It involves developing models - a description of a population or local ecosphere using mathematical concepts - and using these models to make population and environment management decisions. It takes decades of data to get an accurate view on trends in order to create good projections for the future. Climate change is making this particularly difficult. Things are moving very quickly; environments are changing at alarming rates and that throws off predictions. “We are seeing things we have never seen before,” Zarrella Smith warns. All this change is hard to integrate into an existing model, which means fisheries scientists need to carefully consider what historical data to include or exclude in a model in order to get accurate predictions for the future. And rising temperatures aren’t the only issue. Changing currents, salinity changes, and many other dynamic characteristics of the environment affect each other, cautions Zarrella Smith. With these changes in the environment, new species could become more abundant, cold-water species could be moving away from Massachusetts - there are lots of shifts in local populations which make looking at the big picture of ecosystems even more critical, and even more difficult. 

One thing that seems to always be constant is the importance of the work being done in fisheries science. Fisheries support a large portion of the world-wide food supply, and have for a long time, but fisheries don’t know if we can sustain a fish population if researchers don’t know how many fish there are. People like Zarrella Smith are doing the hard work in the field and getting the numbers that are critical for these population estimates. This lets us know what we can fish and can prevent disasters like ecosystem function-loss and species extinction.  

Zarella Smith is particularly happy to be doing this work with her advisor Dr. Adrian Jordaan, who has a long history in the profession. She also has been collaborating with Massachusetts Division of Marine Fisheries, who funds a portion of her research. They are the “folks on the water” and she is happy to be working with them because it really lets her see how fishery science is done at the state level, and they have been essential in conducting her research. Working in OEB has also been a great highlight for her, “OEB students are very welcoming and have a diverse amount of research interests,” she says. Having such a supportive program and collaborators is critically important for upcoming researchers. It is also particularly important as fishery science is a field that, like many STEM fields, is particularly hard on women. “In fisheries it's tough, there’s not a lot of women in many of the spaces in fisheries,” and Zarrella Smith says it isn’t always a welcoming field, but she encourages other scientists to not let this stop them. She believes that no matter who you are, “persistence is key and resilience is key, if you have the passion for it, I would encourage you to make it happen.”  

In the future, Zarrella Smith’s days are probably going to look more like her days on the computer than her days out on her boat. Once she finishes her doctorate, she plans to work in population dynamics for a fisheries science organization such as the National Oceanic and Atmospheric Association. Though this means she will be trading in her captain’s hat for more time on data management, she definitely doesn’t dislike the fieldwork aspect of her work. “It’s important to do the fieldwork to understand where this type of data comes from and how it's generated,” she says. It's critical to remember how much work goes into one data point and at the same time how much information one crew is capable of gathering. It's a lot of work, but Zarrella Smith says she is glad to be doing it: “[What] I enjoy most is the challenge of the job and how forward-thinking and adaptive you have to be to do the work well. I'm challenged in a new way every day, whether planning the field season, collecting the data, at the computer developing code, or crafting science communication.” Zarrella Smith thinks that the joy lies in the challenge itself and in the work it takes to overcome those obstacles. 

Written by Julia LaValley, PhD student in Neuroscience & Behavior, as part of the Graduate School's Public Writing Fellows Program.