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Phosphorus dynamics in the Barents Sea
Author(s) -
Downes Patrick P.,
Goult Stephen J.,
Woodward E. Malcolm S.,
Widdicombe Claire E.,
Tait Karen,
Dixon Joanna L.
Publication year - 2021
Publication title -
limnology and oceanography
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.7
H-Index - 197
eISSN - 1939-5590
pISSN - 0024-3590
DOI - 10.1002/lno.11602
Subject(s) - phytoplankton , oceanography , arctic , environmental science , phosphorus , nutrient , primary production , ecosystem , geology , chemistry , ecology , biology , organic chemistry
The Barents Sea is considered a warming hotspot in the Arctic; elevated sea surface temperatures have been accompanied with increased inflow of Atlantic water onto the shelf sea. Such hydrodynamic changes and a concomitant reduction of sea ice coverage enables a prolonged phytoplankton growing season, which will inevitably affect nutrient stoichiometry and the controls on primary production. During the summer of 2018, we investigated the role of phosphorus in mediating primary production in the Barents Sea. Dissolved inorganic phosphorus (DIP), its most bioavailable form, had an average net turnover time of 9.4 ± 4.8 d. The most southern Atlantic influenced station accounted for both the highest rates of primary production (655 mg C m 2 d −1 ) and shortest net DIP turnover (2.8 ± 0.5 d). The fraction of assimilated DIP released as dissolved organic phosphorus (DOP) at this station was < 4% compared to an average of 21% at all other stations. We observed significant differences between phytoplankton communities in Arctic and Atlantic waters within the Barents Sea. Slower DIP turnover and greater release of DOP was associated with Phaeocystis pouchetii dominated communities in Arctic waters. Faster turnover rates and greater phosphorus retention occurred among the Atlantic phytoplankton communities dominated by Emiliania huxleyi . These findings provide baseline measurements of P utilization in the Barents Sea, and suggest increased Atlantic intrusion of this region could be accompanied by more rapid DIP turnover, possibly leading to future P limitation (rather than N limitation) on primary production.