This technical report by Fisheries and Oceans Canada presents scientific and technical information for a biophysical and ecological overview of the Tuvaijuittuq area in the High Arctic Basin of Nunavut sea ice ecosystem. Tuvaijuittuq was the first Marine Protected Area (MPA) to be designated by a ministerial order under Canada’s Oceans Act in August 2019. The Tuvaijuittuq MPA covers an area of 319,411 km2 and includes the marine waters off northern Ellesmere Island. This region is ecologically significant as it provides important sea-ice habitat and is increasingly being impacted by the effects of climate change, amongst other threats.