At the Roanoke Valley Governor’s School, students are charged each year with carrying out a science fair project, and this year, Abbi Workman, a William Fleming High School freshman, elected to work in the environmental science field. Her project titled The Effect of Crankcase Oil Concentration on the Heart Rate of Daphnia magna won first place at the Governor’s School Student Project Forum on February 8 and will advance to the regional competition on March 15.
“My mom works at the Western Virginia Water Authority, and we talk about water pollution all the time,” said Workman. “I know that storm drain pollution is an environmental concern for urban waterways, and I know that crankcase oil is one of the most common contaminants. I wondered what effect increasing concentrations of crankcase oil might have on our water quality.”
To find out, Workman developed a science experiment to test different oil concentrations on Daphnia magna, a freshwater crustacean commonly used to test water quality. And like most projects at the Governor’s School, this one is complicated.
Workman’s teacher helped her order a supply of Daphnia magna (water fleas) and brought in crankcase oil (motor oil) from her lawn mower, and Workman picked up eggs and distilled water from the grocery store. Workman prepared five solutions of crankcase oil in the concentrations of 0%, 1%, 3%, 7%, and 10%, with 33.5 milliliters of egg whites added to each solution to help mix the oil and water. She spent the month of January in testing.
As a Gov. School student, Workman has access to the extensive Governor’s School lab and bank of computers, and she was able to fully complete her project on-site. For a baseline test, she counted the heart rate of the Daphnia magna at 40X magnification under a dissection microscope, and then she added 1 milliliter of solution, waited 10 minutes, and counted the heart rate again. Throughout 50 painstaking trials, Workman tracked her results through visual observations, box plots, an ANOVA test, and a calculated p-value, and during testing she made some important discoveries.
“I was surprised to find that most Daphnia magna heart rates were unaffected by the solutions of oil. I had hypothesized that if the concentration of crankcase oil in distilled water was increased, then Daphnia magna heart rate would decrease. That seemed a no-brainer. But what I discovered through my research and testing is that much of aquatic life in urban waterways is unharmed by typical levels of storm drain pollution, and that the oil concentrations I used had no significant effect on the water fleas.”
This is good news for fish, but what about people? Is the extensive water filtration process the Water Authority uses enough to keep our drinking water safe? “Absolutely,” said Workman. “Storm drain pollution is a concern for organisms living in rivers and streams, not for people. Our drinking water comes from a reservoir.”
Abbi Workman is just one of the 269 gifted and talented young scientists who attend the Roanoke Valley Governor’s School for Science and Technology. To learn more about the Governor’s School, a half-day regional public STEM school for motivated students in grades nine through twelve, please visit the school’s website at www.rvgs.k12.va.us or contact the school’s director, Dr. John Kowalski, or the school’s guidance counselor, Kathy Sebolt, at 540.853.2116.
