Phosphorus dynamics in the Barents Sea
Phosphorus dynamics in the Barents Sea
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DOI：
10.1002/lno.11602
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发表时间：
2020-09-23
影响因子：
4.5
通讯作者：
Dixon, Joanna L.
中科院分区：
文献类型：
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作者：
Downes, Patrick P.;Goult, Stephen J.;Dixon, Joanna L.
巴伦支海被认为是北极变暖的热点；海面温度上升伴随着大西洋水流入大陆架海的增加。这种水动力变化和随之而来的海冰覆盖率的减少导致浮游植物生长季节延长，这将不可避免地影响营养物质的化学计量和对初级生产力的控制。2018年夏天，我们调查了磷在调节巴伦支海初级生产中的作用。生物有效性最高的溶解无机磷(DIP)平均净周转时间为9.4+/-4.8d，受南大西洋影响最大的站点具有最高的初级生产量(655mgCm(2)d(-1))和最短的DIP净周转(2.8+/-0.5d)。同化DIP以溶解有机磷(DOP)的形式在本站释放的比例为4%，而所有其他站的平均比例为21%。我们观察到巴伦支海内北极和大西洋水域浮游植物群落的显著差异。较慢的DIP周转和较大的DOP释放与北极水域中的棕囊藻群落有关。浮游植物群落的周转速度更快，磷的存留量也更大。这些发现提供了巴伦支海磷利用的基线测量，并表明该地区大西洋入侵的增加可能伴随着更快的倾角周转，可能导致未来对初级生产力的磷限制(而不是N限制)。
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 withPhaeocystis pouchetiidominated communities in Arctic waters. Faster turnover rates and greater phosphorus retention occurred among the Atlantic phytoplankton communities dominated byEmiliania 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.