WEC Alumni in the World - Jesse Senko

Jesse Senko and Loggerhead Turtle

The term, "bycatch," refers to unwanted marine wildlife accidently caught and killed by fishers looking for other species. Jesse Senko (WEC M.S. '09) is working to help keep endangered loggerhead sea turtles from becoming bycatch as part of his PhD research with Arizona State University. His research is conducted in small-scale gillnet fisheries along the Pacific coast of Baja California Sur, Mexico. Jesse explains, "During peak season, one fishing boat may catch as many as eight to sixteen turtles per day, representing among the highest known bycatch rates for sea turtles and other marine megafauna on the planet."

As part of his endeavor, he is testing the effectiveness of attaching LED lights to gillnets to reduce loggerhead bycatch, so that the turtles can then see the lights and avoid the nets. "So far we have found a 50% reduction in loggerhead bycatch rates at night, with no effect on catch rates of target fish species," says Jesse. "Although the lights work well at night, they do not reduce sea turtle bycatch during daytime hours. Given this, I am now planning to test alternative fishing gears, such as fish traps, that would completely eliminate turtle bycatch."

As a graduate student in the WEC department under the advisement of Dr. Ray Carthy, Jesse was able to track his first sea turtle until it was caught and drowned by a gillnet. Over just a few weeks on the coast of Baja California Sur, Mexico, Jesse counted and marked hundreds of other turtles that had met the same fate. While talking to the fishers about this issue, he learned that they would rather not catch the turtles as it caused their nets to tangle. "These conversations, coupled with seeing all these turtles die, inspired me to pursue research that developed and tested solutions to protect turtles from drowning in gillnets, while keeping fishers fishing."

In addition to his work with loggerheads, Jesse writes species-specific sustainable seafood reports for Blue Ocean Institute, a New York-based marine conservation organization. Each report indicates whether a marine species falls under the color-coded category of green (good to eat), yellow (okay to eat), or red (avoid). These colors refer to the sustainability of consuming certain species. To learn more about seafood sustainability and healthy eating choices, log onto http://blueocean.org/programs/sustainable-seafood-program/.

Jesse says avoiding certain seafoods is not the only way to protect ocean wildlife. Replacing plastic bags with reusable cloth ones is also an important component in protecting marine ecosystems. Jesse explains, "A lot of plastic pollution that ends up in the ocean originates in landlocked areas from single use plastic items, and sea turtles and other animals like seabirds end up mistaking these items for jellyfish, fish eggs, and other natural food sources."

Jesse is pleased to have done his masters research with WEC. "I feel strongly that I would not be where I am today if I didn't receive such incredible support from WEC; Dr. John Hayes supported me with a TAship that allowed me to thrive, gain experience and confidence teaching, and generally just feel like I belonged; my advisor Dr. Raymond Carthy nurtured my passion for sea turtles and always supported my research and encouraged me to never give up when things got difficult in the field [. . .] The classes and diversity of faculty at WEC were also helpful in shaping my values, particularly the need for interdisciplinary approaches to conservation issues and the importance of integrating people into any conservation solution."