Assessing Freshwater Influence on Water Column Stability, Nutrient Cycling, and Phytoplankton Productivity in the Canadian Arctic Archipelago

The Canadian Arctic is vital for regulating climate and carbon uptake through ice and freshwater exports and high productivity rates. Changes in physical conditions and nutrient inputs related to freshwater distribution affect marine biota by altering nutrient availability and access(Carmack and McLaughlin 2001). These changes can impact phytoplankton function and productivity. It is known that freshwater is being supplied to the CAA, but the effects of its constituents on coastal ocean production have not been thoroughly studied in the CAA region. This study aims to use stable isotopes and continuous water quality data to assess how freshwater inputs influence water column stability, nutrients, and primary production, specifically focusing on phytoplankton photosynthesis, carbon uptake, and nutrient utilization. The presentation will cover biogeochemical cycling from Nome, Alaska, to Pond Inlet, Nunavut, examining how water properties and productivity vary across the CAA. This will involve single-turnover active fluorescence measurements of gross primary production, continuous water quality assessments, and macronutrient concentrations. Water-stable isotopes will help identify freshwater sources in the coastal Canadian Arctic, including river, glacial, and sea ice melt. Additionally, this presentation will discuss C, N, isotopic composition of suspended particulate organic matter (POM), allowing us to trace the sources and transformation processes of organic matter within the water column. Data collection occurred during a commercial cruise through the Alaskan Arctic and the CAA's Northwest Passage aboard the MS Roald Amundsen from August 23 to September 17, 2022. Our spatial and temporal observations will be extended by comparing them to available satellite measurements. This chemical and biological data provides us with an expansive dataset that gives spatial context to traditional depth profiles and a better understanding of the physical, biological, and chemical properties in this historically understudied region.

Presentation Preference: Oral

Primary Presenter: Frances Crable, University of Illinois at Chicago (fcrabl2@uic.edu)

Authors:

Samira Umar, University of Illinois at Chicago  (sumar3@uic.edu)

Miquel Gonzalez-Meler, University of Illinois at Chicago  (mmeler@uic.edu)

Andrew King, Norwegian Institute for Water Research  (andrew.king@niva.no)