Higher levels of nitrogen are found closer to shore where salinity is lower. This indicates that much of the excess nitrogen found in Casco Bay is coming from land-based sources such as polluted stormwater runoff and sewage treatment plants. y = -0.03x + 1.1, R2 = 0.46* *The trend lines of the graphs throughout this report illustrate the pattern of the data. The equation (y=) describes the trend line that best fits the data. The R2 value tells us how well the data fit around the trend line, indicating the reliability of the line.

03_Nitrogen and Salinity