RUI: Collaborative Research: How does changing glacial coverage affect the transport and fate of DOM and nutrients in coastal watersheds on the Gulf of Alaska?

University Of Alaska Southeast Juneau Campus, Juneau AK

Investigators

Abstract

Glacier thinning rates along the Gulf of Alaska (GOA) are commonly as high as 6-8 m yr-1. This rapid glacial recession has important implications for coastal watershed hydrology and biogeochemistry because the loss of glacier ice decreases hydrologic storage and dramatically alters catchment landcover by exposing new land to the process of primary succession. The ecological development of terrestrial and aquatic ecosystems following deglaciation has been explored extensively, however there has been very little research on how landcover change will alter material delivery into and through the river network to coastal estuaries. This project will fill this critical knowledge gap by evaluating how glacial recession is altering hydrologic and biogeochemical processes in coastal watersheds in southeastern Alaska. In particular, our research will develop a comprehensive understanding of how the speciation, fate and transport of riverine nutrients and dissolved organic matter (DOM) will be altered by ongoing glacial retreat. Weekly and storm sampling combined with continuous discharge measurements will provide the first detailed and complete comparison of nutrient and DOM yields between paired glacial and non-glacial watersheds. Continuous measurements of discharge, oxygen, temperature and turbidity will be used to quantify the effects of glacial meltwater on hydrologic and physical parameters. Experimental approaches (laboratory and field-scale) combined with longitudinal surveys and stream tracers will be used to elucidate the fate of nutrients and DOM during downstream transport. Finally, longitudinal synoptics and source sampling will also be used to access the primary landscape sources of nutrients and carbon to the stream. Ultimately, project findings will provide new insights into how land-to-ocean fluxes of organic and inorganic nutrients are being altered by glacial recession along the GOA and in other glaciated coastal regions. The project will provide laboratory and field research opportunities for undergraduates at the University of Alaska Southeast (UAS), a small, undergraduate university with a high (16%) enrollment of native Alaskan students. Additionally, the project will provide training for one graduate student and one post-doctoral researcher. The integration of undergraduate students in this research project will provide a framework for students and researchers to cooperatively investigate important linkages among climate, landcover change, and hydrological and biogeochemical processes in coastal watersheds. In addition, the project will strengthen an existing partnership between scientists at UAS and naturalists at the Mendenhall Glacier Visitor Center who will work collaboratively to incorporate project results into an interpretive display at the center. The Mendenhall Glacier is the most visited glacier in the United States and hosts over 300,000 visitors each year and thus provides a unique and effective opportunity for public outreach and education related to the findings of this project. Finally, a science educator from Montgomery County, VA will partake in field work during one of the summers. The science educator will bring their experience into the local classrooms and share their experience with their peers.