Presentation on theme: "Introduction The purpose of this project is to discover whether there are higher mercury levels in dragonfly larvae that live in still or moving water,"— Presentation transcript:
Introduction The purpose of this project is to discover whether there are higher mercury levels in dragonfly larvae that live in still or moving water, Our hypothesis is: If we were to measure mercury levels in dragonflies in still versus moving water, then the dragonfly larvae in still water will have higher mercury levels because in still water, the mercury is not being pushed away. In order to make a conclusion and find the answer to this question we had to find some background information. The amount of mercury in a dragonfly depends on how much mercury is in the body of water that the particular dragonfly is living in, or near. Also, if the main food source contains low amounts of mercury, then the dragonfly would have lower amounts of mercury too. Dragonflies are more common in ponds/lakes (still water) than they are in rivers (moving water). Mercury does not exactly form in water. However, according to the EPA, “mercury in air eventually settles into the water where once deposited, certain microorganisms, such as bacteria, change it into methylmercury.” Methylmercury is dangerous to organisms because it is an organic form that can be incorporated into organisms’ bodies. Methylmercury concentrations in fish and other organisms may also be affected by the presence of sulfur and other chemicals in the water which could change if the water was still or moving. The bacteria use the sulfur to create the methylmercury. The most common place to find dragonfly larvae is in places where methylmercury is commonly created, which is on the side of the water in the muddy part because there is a lot of plant life there. The reason we tested the dragonfly larvae is because we could not test the water itself. Materials and methods We were asked to create a research question about levels of mercury. The question could have to do with anything you wanted; our group decided to make ours on the levels of mercury in still versus moving water. Instead of testing the water itself we decided to look at dragonflies that lived in the moving and still water and test the mercury levels of the dragonflies. We went through a process to gather the data needed to answer our question and the information is listed below: Data was collected at Acadia National Park by students using the dirty hands-clean hands method The data was then analyzed at the University of Maine The Locations where data was taken from were : Acadia Otter Creek, Acadia Richardson Brook, Acadia Hodgdon Pond, and Acadia Seal Cove Pond The data we used was from the years 2009, 2011, and 2012 Our collected data was measured in Parts Per Billion (ppb) We chose to use the wet weight (WW) Acknowledgments We would like to thank the following groups and organizations, who helped collect and process the data used in this project: the National Park Foundation, National Park Service, the SERC Institute, Dartmouth College, and the University of Maine, and lastly, all of the students at Woodstock Union High School and the other schools around the country who are involved in this project. Hypothesis If we were to measure mercury levels in dragonfly larvae in both still versus moving water, then the dragonfly larvae in still water will have higher mercury levels because in still water, the mercury is not being pushed away by the moving water. Results Moving water in Acadia had more mercury in dragonfly larvae than still water in Acadia We had more data from Acadia Richardson Brook than Acadia Seal Cove Pond Levels of Mercury in Acadian Dragonfly Larvae; Still Vs. Moving Water Average and Median Mercury Levels Conclusion The purpose of the experiment was to use data for the concentration of mercury in dragonflies in still and moving water, to determine which type of water has more mercury. The hypothesis stated: If the water is still versus moving, then mercury will stay in the still water source because it is not being pushed away by the moving water. The data in the graph shows that our hypothesis was not supported. It shows that instead of the organisms in the still water having more mercury, the organisms from the moving water have more. The average ppb of mercury in the organisms in the moving water was 60.345, and the average of the still water was 21.23 ppb. There were several things that occurred to limit the accuracy of our study. First of all, every body of water is a slightly different size or has a different velocity, ( how fast water is moving,) and therefore will affect mercury levels. Another limitation is that we could only find enough data to support our project in one national park, which was Acadia. Also, we could only find data from two water sources for both still or moving water and not more. Therefore the sources we used are not representing a very diverse account of moving and still water in different land areas and climates. Having more diverse data would give a better average on determining whether there is more mercury in still or moving water. To improve the study, if at all possible, finding more data from a wider variety of national parks would help the accuracy of the experiment. An error that could have occurred to decrease the accuracy of the data is the process of collecting it. When the dragonfly larvae were being collected, there is a chance they could have been contaminated by the students not wearing gloves when handling the organisms and therefore altering the amount of mercury. The overall result of the study shows that there is more mercury in dragonflies in moving water. Is There More Mercury In Still or Moving Water? by Grace Cloutier, Holly Weglarz, and Spruce Bohen Literature cited Conservation, Florida Fish and Wildlife. "Mercury in the Environment." Mercury in the Environment. "Curriculum-Mercury In The Environment." Curriculum-Mercury In The Environment. EPA, n.d. Web. 20 Nov. 2013. Sanchez, Diana M. "Biology Students Research Mercury in Dragonfly Larvae." The Ranger. Sacfirstname.lastname@example.org, n.d. Web. 19 Dec. 2013. "Mercury.utah.gov | Mercury in the Environment." Mercury.utah.gov | Mercury in the Environment. Utah Department of Environmental Quality, n.d. Web. 20 Nov. 2013.