Biogeochemical Controls of Particulate Phosphorus Distribution Across the Oligotrophic Subtropical Pacific Ocean
Biogeochemical Controls of Particulate Phosphorus Distribution Across the Oligotrophic Subtropical Pacific Ocean
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DOI：
10.1029/2020gb006669
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发表时间：
2020-09-01
影响因子：
5.2
通讯作者：
Furuya, Ken
中科院分区：
文献类型：
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作者：
Hashihama, Fuminori;Saito, Hiroaki;Furuya, Ken
研究了南北太平洋副热带真光层（EZ）全海盆范围内颗粒态总磷（TPP）及其相关地球化学参数的分布特征。TPP主要由活的微生物组成，并且其分布可能受典型的N限制的太平洋沃茨中的N供应以及P限制的西北太平洋中的P供应的控制。TPP浓度在大多数站的EZ内显示出垂直均匀分布（约15 nM），但在北太平洋北方的几个站，TPP峰值（>20 nM）出现在EZ较低的地方，那里的硝酸盐和亚硝酸盐浓度较高。TPP与生物地球化学参数之间的关系表明，控制TPP的一个可能的因素在上EZ是二氮固定，而在下EZ是浅化的硝态氮。TPP的地理分布是相对均匀的相比，磷酸盐，从100纳米在北太平洋东部和南太平洋。西北太平洋是一个域，其特征在于较低的溶解有机磷（DOP）浓度，较高的碱性磷酸酶活性，和较高的颗粒聚磷酸盐（PpolyP）：TPP的比例相比，其他域。这些特征表明，积极利用DOP和PpolyP积累可以在维持TPP库存方面发挥重要作用，作为这一独特领域磷酸盐利用的替代品。我们的研究结果表明，TPP分布在整个亚热带太平洋的垂直和地理上是均匀的，掩盖了TPP股票可能是由一系列的营养供应机制。
We investigated basin-wide distributions of total particulate phosphorus (TPP) and associated biogeochemical parameters in the euphotic zone (EZ) of the subtropical North and South Pacific Ocean. TPP is primarily composed of living microorganisms, and its distribution is likely controlled by nitrogen (N) supply in typical N-limited Pacific waters as well as phosphorus (P) supply in P-limited western North Pacific. TPP concentrations showed a vertically uniform distribution (approximately 15 nM) within the EZ at most stations, but at several northern North Pacific stations, TPP peaks (>20 nM) were observed in the lower EZ where nitrate and nitrite concentrations were high. Relationships between TPP and biogeochemical parameters indicate that a possible factor controlling TPP in the upper EZ was dinitrogen fixation and that in the lower EZ was shoaling of the nitracline. Geographical distribution of TPP was relatively uniform compared to that of phosphate, which varied from 100 nM in the eastern North and South Pacific. The western North Pacific was a domain characterized by lower dissolved organic P (DOP) concentrations, higher alkaline phosphatase activities, and higher particulate polyphosphate (PpolyP):TPP ratios compared to other domains. These characteristics indicated that active DOP utilization and PpolyP accumulation could play important roles in the maintenance of TPP stocks as alternatives to phosphate utilization in this distinctive domain. Our results demonstrated that TPP distributions were vertically and geographically uniform across the subtropical Pacific Ocean, concealing that TPP stocks were likely underpinned by a range of nutrient supply mechanisms.