The contribution of the deep chlorophyll maximum to primary production in a seasonally stratified shelf sea, the North Sea
The contribution of the deep chlorophyll maximum to primary production in a seasonally stratified shelf sea, the North Sea
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DOI：
10.1007/s10533-013-9831-7
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发表时间：
2013-02
期刊：
影响因子：
4
通讯作者：
L. Fernand;K. Weston;T. Morris;N. Greenwood;Juan Brown;T. Jickells
中科院分区：
文献类型：
--
作者：
L. Fernand;K. Weston;T. Morris;N. Greenwood;Juan Brown;T. Jickells
结果广泛的巡航在2000年和2001年整个不同的生态流体动力学区域的中部和南部的北海，并用于产生估计的总初级生产和新的生产。一个装有荧光计的波浪形CTD被拖过12，000公里的距离。荧光数据被用来确定叶绿素分布，并得出浮游植物生物量的估计。将这些结果与一次航行试验得出的初级生产（新的和再生的）估计数相结合，以估计更大地理范围内的总生产量。从重复的年际样带的结果表明，温跃层的强度和相关的深叶绿素最大值是可变的。然而，当初级生产力在15-40米的深度集成，年之间的变化是低的。虽然该区域深层叶绿素最大值的深度和强度各不相同，但深层叶绿素最大值（DCM）是该区域在30米左右深度的一个一致和普遍的特征。2001年，计算得出的整个调查地区夏季平均初级生产率为0.91 g C m-2 day-1。这个日生产量相当于夏季层化期的~130 g C m− 2。在多格浅滩和北海中东部附近的近海分层区域，与叶绿素最大值（15-40 m）相关的初级生产力为64 g C m− 2，占夏季分层期间（春季水华后）初级生产力总量的60%。这些地区约66%的新产量发生在DCM。这项研究显示了DCM在北海的程度，并证明了其在春季水华后维持初级生产的重要性。
Results from extensive cruises in the years 2000 and 2001 throughout distinct ecohydrodynamic regions of the central and southern North Sea are presented and used to generate estimates of gross primary production and new production. An undulating CTD fitted with a fluorometer was towed over a distance of 12,000 kms. Fluorescence data were used to determine the chlorophyll distribution and derive estimates of phytoplankton biomass. These results were combined with estimates of primary production (new and regenerated) from experiments from one cruise in order to estimate gross production for a greater geographical extent. Results from repeat inter-annual transects showed that the strength of the thermocline and the associated deep chlorophyll maximum were variable. However, when the primary production was integrated over the 15–40 m depth, the variability between years was low. While the depth and strength of the deep chlorophyll maximum varied across the region, a deep chlorophyll maximum (DCM) is a consistent and widespread feature of this region at around 30 m depth. In 2001 the calculated average primary production rate in summer for the whole area surveyed was 0.91 g C m−2day−1. This daily production equates to ~130 g C m−2for the summer stratified period. In the offshore stratified regions around the Dogger Bank and Eastern Central North Sea primary production of 64 g C m−2associated with the deep chlorophyll maximum (15–40 m) accounted for 60 % of total primary production during the summer stratified period (after the spring bloom). Approximately 66 % of new production in these areas occurred in the DCM. This study shows the extent of the DCM in the North Sea and demonstrates its importance in sustaining primary production after the spring bloom.