Impact of a shrinking Arctic ice cover on marine primary production

TLDR

Loss of Arctic sea ice has accelerated recently, culminating in a 2007 summer minimum ice extent that was 23 % below the previous low. The study aims to quantify the impact of unprecedented ice loss on marine primary production. This was done by coupling satellite‑derived sea ice, sea‑surface temperature, and chlorophyll data to a primary production algorithm parameterized for Arctic waters. Annual Arctic primary production has risen by an average of 27.5 Tg C yr⁻¹ since 2003, with 30 % attributable to reduced ice extent and 70 % to a longer growing season; if trends continue, spring ice loss could triple productivity beyond 1998–2002 levels, potentially altering ecosystem structure and benthic denitrification.

Abstract

Loss of Arctic sea ice has accelerated recently, culminating in a 2007 summer minimum ice extent that was 23% below the previous low. To quantify the impact of this unprecedented loss of ice on marine primary production, we have coupled satellite‐derived sea ice, SST, and chlorophyll to a primary production algorithm parameterized for Arctic waters. Annual primary production in the Arctic has increased yearly by an average of 27.5 Tg C yr −1 since 2003 and by 35 Tg C yr −1 between 2006 and 2007. 30% of this increase is attributable to decreased minimum summer ice extent and 70% to a longer phytoplankton growing season. Should these trends continue, additional loss of ice during Arctic spring could boost productivity >3‐fold above 1998–2002 levels, potentially altering marine ecosystem structure and the degree of pelagic‐benthic coupling. Changes in carbon export could in turn modify benthic denitrification on the vast continental shelves.