Understanding how various watershed features, be they natural or anthropogenically altered, influence riverine biogeochemistry is crucial to management and maintaining aquatic ecosystem health. Net anthropogenic nitrogen and phosphorus inputs (NANI/NAPI) is a relatively simple mass balance approach that allows for the identification of concentrated areas of nutrients in watersheds as a function of human activities that has been successfully linked to predicting loadings into rivers. However, few attempts have been made to assess NANI/NAPI at scales relevant to management and evaluate how changes over time have influenced the relative importance of elemental loading. Here we present a few examples of the applicability of NANI/NAPI as a relevant tool for watershed management at the municipal scale. Furthermore, we show how historical changes and human interventions in the landscape have altered riverine loads and stoichiometries in differential ways as a function of dominant entrance pathways to provide solutions for mitigation.

Primary Presenter: Stéphanie Shousha, University of Montreal (stephanie.shousha@gmail.com)

Authors:

Stéphanie Shousha, Université de Montréal  (stephanie.shousha@umontreal.ca)

Roxane Maranger, Université de Montréal  (r.maranger@umontreal.ca)