A ‘shallow bathtub ring’ of local sedimentary iron input maintains the Palmer Deep biological hotspot on the West Antarctic Peninsula shelf
A ‘shallow bathtub ring’ of local sedimentary iron input maintains the Palmer Deep biological hotspot on the West Antarctic Peninsula shelf
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当地沉积铁输入的“浅浴缸环”维持着西南极半岛陆架上的帕尔默深渊生物热点
DOI：
10.1098/rsta.2017.0171
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发表时间：
2018
期刊：
影响因子：
--
通讯作者：
M. Meredith
中科院分区：
文献类型：
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作者：
R. Sherrell;A. Annett;J. Fitzsimmons;Vincent J. Roccanova;M. Meredith
帕尔默深海（PD）是西南极半岛内陆架沿着的几个生物生产力热点区域之一。热点附近的陆架穿越深槽导致了“峡谷假说”，提出环极深水流向岸边沿着峡谷是上涌的内架，携带营养物质，包括铁（Fe）的表面沃茨，维持浮游植物的水华。我们在这里展示了2015年和2016年1月和2月初采样的PD周围8个站点的溶解和颗粒状Fe和锰（Mn）的全深度剖面，从而首次详细评估了该地区真光层的Fe来源。我们发现，上涌的深水不控制铁通量的表面，相反，浅沉积物来源的铁输入从周围的海岸线水平运输，创建强大的垂直梯度溶解铁在上100米，供应这种限制营养当地生态系统。因此，生物有效铁的供应与深水的峡谷运输没有显著关系。近海岸的时间序列样本显示，当地的冰川融水似乎是一个重要的锰源，但令人惊讶的是，是不是一个大的直接铁输入到这个生物热点。这篇文章是“西南极半岛的海洋系统：在一个快速变化的地区取得进展的现状和战略”主题问题的一部分。
Palmer Deep (PD) is one of several regional hotspots of biological productivity along the inner shelf of the West Antarctic Peninsula. The proximity of hotspots to shelf-crossing deep troughs has led to the ‘canyon hypothesis’, which proposes that circumpolar deep water flowing shoreward along the canyons is upwelled on the inner shelf, carrying nutrients including iron (Fe) to surface waters, maintaining phytoplankton blooms. We present here full-depth profiles of dissolved and particulate Fe and manganese (Mn) from eight stations around PD, sampled in January and early February of 2015 and 2016, allowing the first detailed evaluation of Fe sources to the area's euphotic zone. We show that upwelling of deep water does not control Fe flux to the surface; instead, shallow sediment-sourced Fe inputs are transported horizontally from surrounding coastlines, creating strong vertical gradients of dissolved Fe within the upper 100 m that supply this limiting nutrient to the local ecosystem. The supply of bioavailable Fe is, therefore, not significantly related to the canyon transport of deep water. Near shore time-series samples reveal that local glacial meltwater appears to be an important Mn source but, surprisingly, is not a large direct Fe input to this biological hotspot. This article is part of the theme issue ‘The marine system of the West Antarctic Peninsula: status and strategy for progress in a region of rapid change’.
DOI：
10.1098/rsta.2017.0164
发表时间：
2018-06-28
期刊：
Philosophical transactions. Series A, Mathematical, physical, and engineering sciences
影响因子：
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作者：
Moffat C;Meredith M
通讯作者：
Meredith M