Coastal water darkening and implications for mesopelagic regime shifts in Norwegian fjords
Coastal water darkening and implications for mesopelagic regime shifts in Norwegian fjords
复制标题
DOI：
10.3354/meps08120
复制
发表时间：
2009-01-01
影响因子：
2.5
通讯作者：
Aure, Jan
中科院分区：
文献类型：
--
作者：
Aksnes, Dag L.;Dupont, Nicolas;Aure, Jan
光政权的水柱有很强的结构化影响水生食物网，它以前曾假设，沿海水域变暗增加了成功的触觉捕食者相对于视觉捕食者，如鱼类。由于普遍缺乏时间序列的光学参数，我们采用了代理光衰减，这取决于盐度和溶解氧在一年中的叶绿素浓度低的时候。我们目前的证据表明，挪威沿海沃茨已经变暗，在1935年至2007年期间的清新的结果。我们的研究结果表明，沿海水渗透到深盆地的位置很容易出现水柱变暗，特别是如果溶解氧也下降了。我们估计，在33至35 PSU和1至6 ml O-2 l（-1）的范围内，盐度和氧的变化与200 m深度的无色素水柱中光子通量的8个数量级的差异有关。我们的研究结果表明，这样的变暗需要考虑在中层制度的变化，涉及大量发生的水母Periphylla periphylla的分析。
The light regime of the water column has a strong structuring effect on aquatic food webs and it has been previously hypothesized that coastal water darkening has increased the success of tactile predators relative to visual predators such as fish. Due to a general lack of time-series of optical parameters, we applied a proxy for light attenuation that depends on salinity and dissolved oxygen at a time of the year when chlorophyll concentrations were low. We present evidence that coastal waters of Norway have darkened as a result of freshening over the period 1935 to 2007. Our results suggest that locations where coastal water penetrates into deep basins have been prone to water column darkening, particularly if dissolved oxygen has also declined. We have estimated that salinity and oxygen variation on the ranges 33 to 35 PSU and 1 to 6 ml O-2 l(-1) are associated with up to 8 orders of magnitude difference in photon flux at 200 m depth in a water column devoid of pigments. Our results suggest such darkening needs to be considered in analyses of mesopelagic regime shifts involving mass occurrence of the jellyfish Periphylla periphylla.