TSU student's project focuses on impact of amphipod on roots

TSU Wildlife, Sustainability and Ecosystem Sciences Department
Neesa Johnson, a Tarleton undergraduate student in the Wildlife, Sustainability, and Ecosystem Sciences Department, works on her undergraduate project of researching the effects of Mexican scud on lettuce roots in a hydroponic system.

Neesa Johnson is a Tarleton undergraduate student in the Wildlife, Sustainability, and Ecosystem Sciences Department.

She started her undergraduate project researching the effects of Mexican scud (small, shrimp-like amphipod) on lettuce roots in a hydroponic system. Mexican scud consumes organic matter in water, like fish feces, and keeps lettuce roots white and functioning efficiently in an aquaponics system. Johnson’s research is to determine if their presence in the root zone is beneficial or harmful.

It turns out that the scud could not tolerate the full-strength hydroponics nutrient solution, which is high salt. The study is conducted in the hydroponics system to design a worst-case scenario where the only food for the scud is the lettuce roots (no fish feces/more control of nutrients for replication).

Concluding that scud will consume each other when fed only cucumber slices in the nutrient solution trials, the scud population was reduced by about 25 percent.

The project has now shifted to determining how to reduce scud self-predation by inventing structures to use in the system that provides more square footage for scud to occupy and control the appropriate amount and type of food, while also determining how to grow lettuce in either 1/4 or half strength nutrient solution.