Overwinter oxygen and silicate dynamics in a high Arctic lake (Immerk Lake, Devon Island, Canada)

ABSTRACT

Arctic lakes are ice covered for 8–12 months of the year, but the duration and thickness of ice cover is decreasing with increased warming. There is a paucity of baseline data documenting the geochemical dynamics of nutrients and oxygen beneath ice cover of high Arctic lakes, a gap that presents a challenge when attempting to understand the impacts of a rapidly changing Arctic on lake ecosystems. We present an annual cycle of temperature, oxygen, and silicate data from Immerk Lake on Truelove Lowland, Devon Island, Canada. Water column oxygen concentrations decreased while silicate concentrations increased during the ice-covered season. Ice cover melting during spring–summer is associated with rapid net decreases of the silicate standing stock at almost 3 times the rate of its net increase over winter. These data show the importance of the extended winter season for regeneration of silicate, an essential nutrient for diatom populations, which are important members of the phytoplankton community and carbon cycle of Arctic lakes. These data collected 60 years ago serve as a benchmark and document the water column oxygen and silicate dynamics in an Arctic lake during ice formation, winter darkness, and ice-cover melting periods.

KEYWORDS:

• Arctic
• lake
• oxygen
• silica
• under-ice
• winter limnology

Acknowledgements

This work is a tribute to the legacy of Spencer Apollonio, and an indication of how forward thinking his scientific ideas were and remain. ABM would like to acknowledge and honor Spencer for his friendship, stories, and inspiring love of science, especially the Arctic, to the very end. The authors thank Paty Matrai, David Emerson, and Laura Sofen for comments on the manuscript. Thanks to Caroline Moseley at the Bowdoin College Library for scanning field notebooks. This work was part of the Devon Island Expedition (1960–1963) of the Arctic Institute of North America. SA led the Devon Island expedition and braved the Canadian Arctic winter to collect and analyze the Immerk Lake samples and helped to write the manuscript. ABM analyzed the data and wrote the manuscript. Both authors approve the final submitted version.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Availability of data and material

No sample material remains from this study. All data used in this manuscript are publicly available at https://github.com/abmichaud/truelove. R code used in this study is publicly available and explained at https://github.com/abmichaud/truelove.

Additional information

Funding

The field sampling was supported by funds and supplies from the Arctic Institute, Defense Research Board of Canada, National Research Council of Canada, Royal Society, United States Steel Foundation, Hudson’s Bay Company, Office of Naval Research (USA), Massey-Ferguson Ltd., United States Weather Bureau, Meteorological Branch of the Department of Transportation (Canada), and Quartermaster Corps of the United States Army. ABM was supported by a grant from National Science Foundation (USA) (#1754358 awarded to D. Emerson).