Concentrations of sunscreens and antioxidant pigments in Arctic Calanus spp. in relation to ice cover, ultraviolet radiation, and the phytoplankton spring bloom
Concentrations of sunscreens and antioxidant pigments in Arctic Calanus spp. in relation to ice cover, ultraviolet radiation, and the phytoplankton spring bloom
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DOI：
10.1002/lno.10194
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发表时间：
2015-11-01
影响因子：
4.5
通讯作者：
Nielsen, Torkel Gissel
中科院分区：
文献类型：
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作者：
Hylander, Samuel;Kiorboe, Thomas;Nielsen, Torkel Gissel
北极的浮游动物在春季上升到较浅的深度，以吃每年发生的浮游植物水华。然而，在表面沃茨中，它们暴露于有害的紫外线辐射（UVR）水平。在这里，我们量化了已知具有紫外线保护功能的物质的浓度，即类菌孢素氨基酸（MAAs）和类胡萝卜素虾青素，从3月到5月在Calanus finmarchicus，Calanus glacialis和Calanus hyperboreus。3月初，冰层覆盖率为100%，4月开始破裂，5月底消失。水柱中的UVR暴露与冰况密切相关，水的UVR透明度高达6米（1%辐射的深度）。C. finmarchicus和C.冰川期间急剧增加，并达到峰值同时最大叶绿素a（Chl a）水平。C. hyperboreus增加后，根据它的后到达的表面。随着时间的推移，所有三个物种中的虾青素浓度增加，但没有与冰条件或浮游植物水华同步。即使只有上6米的水柱受到紫外线辐射的影响，MAAs在桡足类是密切相关的紫外线的威胁。因此，预计冰盖的变化将对浮游动物的紫外线照射产生很大影响，强调浮游动物从深水沃茨上升的时间与浮游植物水华和冰破裂有关的重要性。
Arctic zooplankton ascend to shallow depths during spring to graze on the yearly occurring phytoplankton bloom. However, in surface waters they are exposed to detrimental ultraviolet radiation (UVR) levels. Here, we quantified concentrations of substances known to have UVR-protective functions, namely mycosporine-like amino acids (MAAs) and the carotenoid astaxanthin, from March to May in Calanus finmarchicus, Calanus glacialis and Calanus hyperboreus. Ice cover was 100% in the beginning of March, started to break up during April and was gone by the end of May. UVR-exposure in the water column was tightly linked to the ice conditions and water UVR-transparency was up to 6 m (depth where 1% radiation remains). Concentrations of MAAs in C. finmarchicus and C. glacialis increased sharply during ice break-up and peaked concurrently with maximum chlorophyll a (Chl a) levels. MAA-concentrations in C. hyperboreus increased later in accordance with its later arrival to the surface. The concentration of astaxanthin increased in all three species over time but there was no synchrony with ice conditions or the phytoplankton bloom. Even though only the upper 6 m of the water column was affected by UV-radiation, MAAs in the copepods were tightly correlated to the UV-threat. Hence, changes in ice cover are projected to have a large impact on the UVR-exposure of zooplankton emphasizing the importance of the timing of zooplankton ascent from deep waters in relation to the phytoplankton bloom and the ice break-up.