Seasonal distribution of dissolved inorganic carbon and net community production on the Bering Sea shelf
Seasonal distribution of dissolved inorganic carbon and net community production on the Bering Sea shelf
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DOI：
10.5194/bg-7-1769-2010
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发表时间：
2010-05
期刊：
影响因子：
4.9
通讯作者：
J. Mathis;J. Cross;N. Bates;S. B. Moran;M. Lomas;C. Mordy;P. Stabeno
中科院分区：
文献类型：
--
作者：
J. Mathis;J. Cross;N. Bates;S. B. Moran;M. Lomas;C. Mordy;P. Stabeno
抽象的。为了评估白令海东南部的净群落生产量(NCP)的现状，我们测量了2008年春季和夏季由不同生物地球化学性质定义的6个陆架区DIC浓度的时空分布和控制。春季DIC浓度与盐度密切相关，内陆架DIC浓度为1900μmoles kg−1，白令海深水DIC浓度为2400μmoles kg−1。在夏季，由于海冰融化、陆地输入和初级生产的稀释，DIC浓度较低。在内陆架上的浓度低至1800μ摩尔·kg−_1。我们发现，由于春季和夏季之间的初级生产和碳酸钙的形成，在水柱上部30米处，DIC浓度下降了30-150μ摩尔kg−1。根据DIc的季节下降，估计内、中、外陆架的NCP速率平均为28±9mmolCm−2d−1，而在富营养化盆地水和富铁陆架水最汇合的“绿化带”，NCP速率较高(40~47mmolCm−2d−1)。我们估计，2008年，整个货架上的净生产总值约为96 Tg C yr−1。由于缺乏一致的、可比较的生产率数据，目前无法量化该系统的生产率正在提高还是下降。然而，随着气候变化继续改变白令海的特征，我们已经表明，NCP可以成为生态系统如何运作的重要指标。
Abstract. In order to assess the current state of net community production (NCP) in the southeastern Bering Sea, we measured the spatio-temporal distribution and controls on dissolved inorganic carbon (DIC) concentrations in spring and summer of 2008 across six shelf domains defined by differing biogeochemical characteristics. DIC concentrations were tightly coupled to salinity in spring and ranged from ~1900 μmoles kg−1 over the inner shelf to ~2400 μmoles kg−1 in the deeper waters of the Bering Sea. In summer, DIC concentrations were lower due to dilution from sea ice melt, terrestrial inputs, and primary production. Concentrations were found to be as low ~1800 μmoles kg−1 over the inner shelf. We found that DIC concentrations were drawn down 30–150 μmoles kg−1 in the upper 30 m of the water column due to primary production and calcium carbonate formation between the spring and summer occupations. Using the seasonal drawdown of DIC, estimated rates of NCP on the inner, middle, and outer shelf averaged 28 ± 9 mmoles C m−2 d−1. However, higher rates of NCP (40–47 mmoles C m−2 d−1) were observed in the "Green Belt" where the greatest confluence of nutrient-rich basin water and iron-rich shelf water occurs. We estimated that in 2008, total NCP across the shelf was on the order of ~96 Tg C yr−1. Due to the paucity of consistent, comparable productivity data, it is impossible at this time to quantify whether the system is becoming more or less productive. However, as changing climate continues to modify the character of the Bering Sea, we have shown that NCP can be an important indicator of how the ecosystem is functioning.