Winter is an important season for many limnological processes, which can range from biogeochemical transformations to ecological interactions. Interest in the structure and function of lake ecosystems under ice is on the rise. Although limnologists working at polar latitudes have a long history of winter work, the required knowledge to successfully sample under winter conditions is not widely available and relatively few limnologists receive formal training. In particular, the deployment and operation of equipment in below 0°C temperatures pose considerable logistical and methodological challenges, as do the safety risks of sampling during the ice-covered period. Here, we consolidate information on winter lake sampling and describe effective methods to measure physical, chemical, and biological variables in and under ice. We describe variation in snow and ice conditions and discuss implications for sampling logistics and safety. We outline commonly encountered methodological challenges and make recommendations for best practices to maximize safety and efficiency when sampling through ice or deploying instruments in ice-covered lakes. Application of such practices over a broad range of ice-covered lakes will contribute to a better understanding of the factors that regulate lakes during winter and how winter conditions affect the subsequent ice-free period.
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We would like to thank two anonymous reviewers for their valuable comments which have substantially improved this manuscript. We would also like to thank participants of the Global Lakes Ecological Observatory Network (GLEON) 19 All Hands’ Meeting for their initial input and recommendations; partial support for the GLEON 19 meeting was provided by NSF grant EF-1137327. GLEON provided the platform to further develop our ideas and continue the work of the Ecology under Lake Ice working group (NSF DEB 1431428). This project was partially supported by the Great Lakes Fishery Commission with the assistance of Senator Patrick Leahy. J. Ellen Marsden and Ted Ozersky provided helpful comments and reviewed the completed manuscript prior to submission.
© 2018 Association for the Sciences of Limnology and Oceanography