J. Geophys. Res. Oceans http://doi.org/ctsj (2018)

Sea-ice algae are the cornerstone of ecological activity in the Arctic, fuelling upper trophic levels during spring blooms. However, ice algae production is threatened by anthropogenic warming, specifically through changes in sea-ice thickness, the timing of advance and retreat, and associated shifts in overlying snow. Virginia Selz and colleagues from Stanford University, USA, examine the drivers of ice algae variability in the Chukchi Sea over the period 1980–2015 using a using a one-dimensional coupled physical–biological ice ecosystem model alongside observations.

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Buiten-Beeld/Alamy Stock Photo

Annual ice algal net primary production is found to have decreased by 22% since 1980. This reduction can be attributed to the earlier melt and retreat of sea ice, which decreases the length of the algal growing season. However, thinner overlying snowpacks — and therefore greater light availability — could potentially offset melt-driven algal declines by promoting earlier bloom onset. Thus, while projected changes in Arctic sea ice imply continued reductions in ice algal productivity in the Chukchi Sea, thinner snow cover may partially alleviate these losses and offer some hope for Arctic ecological interactions.