It is early morning, and Bildad Eta Eyong is literally thigh deep in his work searching the Gallinas River for insects. As the primary source of water for Las Vegas, N.M., the approximately 98-square-mile Gallinas River watershed cuts across time, through Precambrian Paleozoic and Mesozoic strata. Along its journey from Elk Mountain to the Pecos River, the Gallinas accumulates varying traces of arsenic through erosion. “In general, you find arsenic from geologic or mining sources,” says Eyong, a graduate student at New Mexico Highlands University. “Here in the Gallinas, the source is geology from the shale formations that dominate the major part of the watershed.” Eyong hopes, through his study of invertebrates along the watershed, to provide a better understanding of arsenic levels in the river compared to water samples taken throughout the year. “During spring runoff, the level is high, but at other times it doesn’t register,” Eyong says. “There’s an advantage to using the invertebrates. They can tell you how the levels are affecting the water system, not just at a point in time as with a water sample test.” In addition to examining the levels of arsenic in invertebrates, Eyong is studying how the levels move up the food chain along the watershed. “Some fish prey principally on invertebrates,” Eyong says. “If the invertebrates are the main food source, that’s another reason why they’re so important to study.” Dr. Edward Martinez, Eyong’s adviser for the project, says the work Eyong and other graduate students, who are studying arsenic levels in plant life and urban runoff, will give researchers a baseline for future research.”I don’t like to call it contamination, since the levels are naturally occurring,” Martinez says. “It’s important to see how urban activities are impacting the watershed and examine things we can mitigate in the future. “The invertebrates have a lifespan of months, so we’re getting a different picture,” Martinez says. “We can use the invertebrates to test the water quality and the health of the stream. Since the 1980s, the EPA has begun to accept using invertebrates for water quality. The invertebrates live there and are exposed to the contaminates throughout their life cycle.”To assist in his research, Eyong received a $5,000 grant from the New Mexico Water Resources Research Institute through the WRRI Student Research Grant Program. The grant will help Eyong pay for lab analysis. “To get the metals out of the sediments, we need to send them out,” Eyong says. “It’s fortunate the program exists, since it really helps. The research project could have been completed without the grant, but it would have taken much longer, since we would have been trying to find out how we can pay for the analysis.” Eyong said he hopes one day to take his experience in analyzing water quality back to his native country, Cameroon, and help improve the lives and health of his countrymen.According to the CIA World Factbook, water contamination is a top environmental concern for the African country of 18 million, and the risk is very high for waterborne infectious diseases. “Studies like this are not done on a day-to-day basis in Cameroon,” says Eyong, who plans to pursue a Ph.D. after he gains more experience in the field. “We have industrial cities, and there is much contamination.”