Young Naturalist Awards
The Young Naturalist Awards is the Museum's research-based science competition for students in grades 7 through 12. Below, read about one of the 2011 winners, who studied bioluminescent dinoflagellates, and visit the Young Naturalist Awards site to read the contest guidelines and find out more about the competition.
The Rebound Effect: Student Studies DEET's Effect on Dinoflagellates
Puerto Rico is one of the few places on Earth with bioluminescent bays. A favorite destination for tourists, these inlets glow at night when swimmers agitate the waters’ light-emitting dinoflagellates, or tiny photosynthetic microbes.
Seventeen-year-old Ryan wanted to understand whether the popular insect repellant DEET, worn by many tourists to ward off mosquitoes, had any effect on the dinoflagellates in these bays. His investigation, outlined in the essay The Effects of DEET on the Bioluminescent Dinoflagellate, Pyrocystis fusiformis, earned Ryan one of the 2011 Young Naturalist Awards.
Ryan hypothesized that the presence of DEET in the water would adversely affect the dinoflagellates’ ability to luminesce. To test his prediction, Ryan used black garbage bags and duct tape to convert wooden shelves into near-complete darkness experimentation areas. He added several solutions with varying concentrations of DEET to flasks filled with dinoflagellates, also monitoring a control group that contained distilled water. After setting a timed lamp to mimic 12-hour cycles of daylight and darkness, Ryan agitated each culture with a swirl and measured their illuminance with a light sensor.
Upon recording the dinoflagellates’ maximum illuminance each day, Ryan realized his results did not support his hypothesis. While dinoflagellates exposed to the lower (.01 to .1 percent) concentrations of DEET emitted significantly less light than the control group on the first day of the trial, they rebounded on the second day and performed as well as the control throughout the rest of the experiment. The dinoflagellates that experienced the highest concentration of the repellant (1 percent) died, leading Ryan to conclude that these organisms may rebound from the stresses of DEET up to a certain threshold.
Ryan acknowledges the limits of his investigation and hopes he can conduct another one in the future that would take into account the amount of DEET that leaves a swimmer’s skin and enters the water. This information, he believes, “would aid scientists and conservationists in evaluating the policies regarding swimming in some bioluminescent bays.”
The Young Naturalist Awards are proudly supported by Alcoa Foundation.