Correlation between Nutrient Concentrations and Chlorophyll a within an Agricultural Stream
Faculty Mentor Information
Katlyn Gonzalez- Author Sarah Stader- Mentor Rebecca Hale- Mentor
Abstract
Rangeland and croplands in the intermountain west are increasingly important as they account for almost 65% of the land use in this region, which has inherently changed the structure and function of streams. Agriculture is often associated with elevated concentrations of nutrients, such as nitrogen and phosphorous, which are, in addition to turbidity, known to control primary production in lotic habitats. We hypothesized that elevated nutrient levels in the growing season will be associated with higher levels of chlorophyll a in stream water. To test this, we sampled stream water monthly for nutrient and chlorophyll a concentrations at nine sites longitudinally along Marsh Creek, an agriculturally-dominated stream in southeastern Idaho. We expect to observe a positive correlation between nutrient concentrations and chlorophyll a across sites as well as over time. However, an alternative hypothesis is that primary production results in an uptake of nutrients, leading to a negative correlation between chlorophyll a and nutrient concentrations. The relationship between nutrient density and chlorophyll a will be determined through further analysis.
Correlation between Nutrient Concentrations and Chlorophyll a within an Agricultural Stream
Rangeland and croplands in the intermountain west are increasingly important as they account for almost 65% of the land use in this region, which has inherently changed the structure and function of streams. Agriculture is often associated with elevated concentrations of nutrients, such as nitrogen and phosphorous, which are, in addition to turbidity, known to control primary production in lotic habitats. We hypothesized that elevated nutrient levels in the growing season will be associated with higher levels of chlorophyll a in stream water. To test this, we sampled stream water monthly for nutrient and chlorophyll a concentrations at nine sites longitudinally along Marsh Creek, an agriculturally-dominated stream in southeastern Idaho. We expect to observe a positive correlation between nutrient concentrations and chlorophyll a across sites as well as over time. However, an alternative hypothesis is that primary production results in an uptake of nutrients, leading to a negative correlation between chlorophyll a and nutrient concentrations. The relationship between nutrient density and chlorophyll a will be determined through further analysis.