Insects vs Oil
Nia Davis-McGregor
Island Pacific School
Floor Location : J 139 V

In this project I attempted to determine how an oil spill would affect a soil ecosystem by observing avoidance behaviour of springtails (specifically, Folsomia candida). This project is important because springtails are a very valuable part of the soil ecosystem. They transport beneficial spores of fungi that form mycorrhizae around the roots of plants. They also feed on harmful fungi and bacteria that accumulate around plant roots. They grow by molting rather than going through a life cycle with complete metamorphosis, and the females commonly reproduce without males. This species is found commonly throughout the world. For my experiment, I mixed potted soil with different amounts of motor oil to simulate an oil spill. Then, filled one side of twenty five petri dishes with uncontaminated soil and with five of them I filled the other side with clean soil too. Those five were the negative controls. With the rest of the dishes, I filled the other side with soil contaminated with different amounts of motor oil. Not including the controls, there were four different amount of oil mixed into soil. After the petri dishes were prepared, I dropped approximately 20 springtails into each dish, sprayed in a small amount of water, and left the dishes in a controlled environment chamber for 24 hours. After 24 hours, it was time to count up how many springtails were on each side of every petri dish. I added 100 ml water to a wide beaker and dropped in the soil from one side of a petri dish. I put on a head magnifier and counted how many springtails floated to the top. If they are alive, springtails will try to climb to the surface of water. I was focusing on how many springtails were on the clean side of each petri dish because if my hypothesis was correct, there would be a larger amount of springtails on the clean side than the dirty side. In the controls, there would be about 10 on each side. My results were very interesting because there are three ways that they could be interpreted. The first way is that my hypothesis was correct - the springtails avoided the oil contaminated soil and moved to the clean soil. The second way is that they motor oil could have killed a large amount of the springtails and then I wouldn't be able to count them, and the last way is that springtails were trapped under water by oil in soil when I was counting them. That would mean that they could not be counted.