Results

As shown above, the species Aeshnidae has the highest concentration of methylmercury in their bodies, and Beaver Brook Bridge had the most mercury concentrated larvae. The methylmercury concentrations from greatest to least within the larva are: Aeshnidae, Cordulegastridae, Gomphidae, Macromiidae, Libellulidae, and with the lowest concentration is Corduliidae.

Background/ IntroductionBeaver Brook is located throughout different towns within New Hampshire and Massachusetts. The brook travels through the town of Pelham, New Hampshire where the student researchers attend Pelham High School. A majority of Beaver Brook wetland is located behind the school grounds which is labeled on local maps as “Pelham Schools Natural Area.” The research conducted for this project was conducted at two sites in the “Pelham Schools Natural Area” and a local town beach.

The dragonfly larva was collected from three different locations along the same brook with three different soil types to identify if the soil had an effect on the methylmercury intake in the dragonfly larva. The three different soil locations were a sandy beach area, a beaver dam with packed in dirt, and an area where the water flows smoothly and the dirt sits freely at the bottom.

Methylmercury in dragonfly larva proves that organisms are absorbing this toxic waste and local individuals are not aware of this. Now that it can be seen how organisms absorb the methylmercury, it is important that we find out if the organisms for example, fish caught at the town beach, have levels that are causing harm in the food chain.

Materials and methodsThe classes used the clean hands / dirty hands procedure and with this procedure, there are two designated people who handle the larva. One person is clean hands, wearing gloves and not touching anything besides the bags that the larva will go in, and the other is dirty hands and is in charge of transferring the larvae from the containers they were held in after collection to their individual bags they will freeze in. The dirty hands people can touch everything except the bags the larvae will go in. this helps to eliminate the possibilities of cross contamination. The materials used consisted of clear plastic containers to hold the larva in as they were collected, nets used to find the larva at the bottom of the brook, plastic spoons to transfer the larva from the containers to their individual bags, plastic bags to keep each larva separate as they go into the freezing process, and gloves to insure no cross contamination and for cleanliness.

Acknowledgments

Conclusions and discussionThe data and charts indicated that the flowing water at Beaver Brook Bridge absorbs and holds more methylmercury than the still pond water at Beaver Brook, and sandy soil at Beaver Brook at Willow street. In the study, we have an inconsistent amount of data for each species. Preferably, we would like to have at least 4-5 specimens for each species, to get an accurate information.  The data charts show that bioaccumulation is predominantly greatest at Beaver Brook Bridge, compared to the sandy soil at Beaver Brook at Willow Street, and the dam at Beaver Brook. Next year's class, would like to conduct a similar study, first to see if there are similar soil results and secondly, if the concentrations of methylmercury are higher in the male dragonflies than females.

Alex Deacon and Kaitlyn MinichielloPELHAM HIGH SCHOOL

Literature cited"Mercury in the Environment." Mercury in the Environment. U.S. Department of the Interior, 19 Feb. 2009. Web. 31 Dec. 2015.Zhang, Zhong Sheng, Dong Mei Zheng, Qi Chao Wang, and Xian Guo Lv. "Bioaccumulation of Total and Methyl Mercury in Three Earthworm

Species (Drawida Sp., Allolobophora Sp., and Limnodrilus Sp.)." Bulletin of Environmental Contamination and Toxicology. Springer Verlag, 25 Sept. 2009. Web. 31 Dec. 2015.

Woodruff, Laurel G., and William F. Cannon. "Total Mercury, Methylmercury, and Selected Elements in Soils of the Fishing Brook Watershed, Hamilton County, New York, and the McTier Creek Watershed, Aiken County, South Carolina." USGS Science for a Changing World, 2008. Web. 31 Dec. 2015.

Carigan, Richard, Virginie Roy, and Marc Amyot. "Beaver Ponds Increase Methylmercury Concentrations in Canadian Shield Streams along Vegetation and Pond-Age Gradients." - Environmental Science & Technology. Environmental Science and Technology, 1 July 2009. Web. 31 Dec. 2015.

BEAVER BROOK WATER STUDY

Research reported in this publication was supported by the National Institute Of Environmental Health Sciences of the National Institutes of Health under Award Number P42ES007373. The content is solely the responsibility of the authors and does not necessarily represent the official

views of the National Institutes of Health.

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Beaver Brook Dam – Packed Mud

Beaver Brook at Willow Street - Sand

Beaver Brook Bridge - Loose Mud

Research Question Is there a Correlation Between Sandy Soil and Packed Mud or Where Water is Flowing Over Mud and the Methylmercury Levels?