DURHAM, N.C.—Isabel Hillman (MEM’19) worked with The Nature Conservancy (TNC) for her Master’s Project (MP) to identify and prioritize areas in North Carolina’s Albemarle-Pamlico watersheds where improved nutrient management can be most effective.

An MP combines the academic rigor of a thesis with the practical experience of an internship. Working singly or in groups, students apply skills and knowledge they’ve acquired in the classroom to tackle real-world environmental challenges for real clients through a well-formulated and defensible analysis. It is a culminating experience for\all Master of Environmental Management (MEM) and Master of Forestry (MF) students at the Nicholas School of the Environment.

Duke Environment recently corresponded with Hillman, who is pursuing an MEM in ecosystem science and conservation, to discuss the goals and key findings of her MP as well as how the findings could potentially improve TNC’s conservation efforts.

What is the goal of your MP?
“The goal of this MP is to help the North Carolina branch of The Nature Conservancy to prioritize their nutrient management efforts in the Albemarle-Pamlico watersheds.
“Nutrient problems leading to poor water quality are widespread, but the Albemarle-Chowan, Roanoke and Tar-Pamlico watersheds are so large that TNC cannot pursue management everywhere. Our objectives were to determine where nutrient concentrations are highest across the landscape, what management options are available to TNC to address nutrients in these locations, and find out who the relevant landowners to contact are.”

What challenges did you encounter with your work?
“The biggest challenge of this project was reorganizing our work to account for the federal government shutdown. The government closing delayed the release of USGS-provided SPARROW model results, so the results incorporated in this project are a draft version. It also postponed the release of the 2016 NLCD (land cover) data until April, which was too late to integrate into our analysis.”

What are the key findings of your MP?
“There were 3 key findings as a result of this work:
1) “Nutrient concentrations vary across the Albemarle-Pamlico watersheds, and high concentrations of nitrogen and phosphorus are associated with development and agriculture.

2) “Since nutrient concentrations are not consistent, TNC should prioritize their management efforts in nutrient hot spots to be most efficient at removing nutrients from the system.

3) “Our efforts focused on best management practices (BMPs) available in agriculturally dominated hot spots. There is not a clear BMP that should be pursued in all situations. Different BMPs have different potentials for efficiency of nutrient removal per unit of land and overall impact across the landscape, but interventions will rely mostly on the willingness of the landowners to pursue a particular option”.

What are 2-3 key challenges to removing pollutants from the Albemarle-Chowan, Roanoke, and Tar-Pamlico watersheds?
“The spatial and temporal variability of nutrients in these watersheds make them difficult to address. This is compounded by the fact that nonpoint sources contribute significantly to the pollution. Water-quality data collected throughout the region does a good job of showing nutrient levels at certain points, but does not provide specific information about where nutrients are coming from. Correctly identifying where nonpoint pollution is originating and implementing BMPs that efficiently address it with limited resources is very challenging.”

Are your findings a model or baseline that could be adopted by regions with similar watershed issues?
“A similar approach to identifying where nutrients are concentrated is applicable to other watersheds. However, some model inputs are region specific, so they would need to be altered to replicate this work in a different location.

“This is the study area:



“This is a raw InVEST model output:


“One of the most important aspects of this project was taking the export shown above and converting it into something more user friendly for TNC. We did this through a hot spot analysis that produced the map shown below.”