Underwater Optics in Sub-Antarctic and Antarctic Coastal Ecosystems.
Underwater Optics in Sub-Antarctic and Antarctic Coastal Ecosystems.
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DOI：
10.1371/journal.pone.0154887
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发表时间：
2016
期刊：
影响因子：
3.7
通讯作者：
Gómez I
中科院分区：
文献类型：
--
作者：
Huovinen P;Ramírez J;Gómez I
了解自然沃茨水域的水下光学对于评估水生初级生产力和水生栖息地的紫外线暴露风险至关重要。与全球气候变化相关的环境条件不断变化，这意味着水下光气候的潜在对比变化，进一步强调了深入了解与水下光学相关的模式的必要性，以便更准确地预测未来。本研究评估了太阳辐射在智利北巴塔哥尼亚地区（39-44°S）和南极海湾（62°S）的六个亚南极河口和峡湾的渗透。根据垂直漫衰减系数（Kd），来自测量与潜水多通道辐射计，平均夏季紫外线穿透深度（z1%）在这些水体中的UV-B（313 nm）为2-11米，UV-A（395 nm）为4-27米，和7-30米的PAR（真光区）。紫外线衰减最强的是在浅的Quempillén河口，而菲尔德斯湾（南极洲）的透明度最高。光学不均匀的水层和透明度的季节性变化（冬季较低）的特点科马峡湾和Puyuhuapi通道。在一般情况下，多元分析的基础上的紫外线和PAR波长的Kd值区分强烈Quempillén河口和Puyuhuapi通道从其他研究地点。瓦尔迪维亚河河口内的空间（水平）变化反映了较强的衰减区域接收河流的影响，而菲尔德斯湾内的水透明度较低的空间变化一般与冰川的接近程度，可能是由于增加浊度通过冰驱动的过程。在菲尔德斯湾观测到的与紫外线-A/可见光波长成比例的较高透明度和较深紫外线-B穿透表明，对南极生态系统的风险较高，这反映在例如紫外线-B损害的改变与紫外线-A/PAR下的光修复之间。考虑到损害修复过程在低温下往往会减慢，该地点的低温以及臭氧消耗事件可能会进一步加剧紫外线的不利影响。总体而言，结果强调了显着的空间（水平和垂直）和时间的光学特性的异质性，这些意味着水下光学估计的挑战。
Understanding underwater optics in natural waters is essential in evaluating aquatic primary production and risk of UV exposure in aquatic habitats. Changing environmental conditions related with global climate change, which imply potential contrasting changes in underwater light climate further emphasize the need to gain insights into patterns related with underwater optics for more accurate future predictions. The present study evaluated penetration of solar radiation in six sub-Antarctic estuaries and fjords in Chilean North Patagonian region (39–44°S) and in an Antarctic bay (62°S). Based on vertical diffuse attenuation coefficients (Kd), derived from measurements with a submersible multichannel radiometer, average summer UV penetration depth (z1%) in these water bodies ranged 2–11 m for UV-B (313 nm), 4–27 m for UV-A (395 nm), and 7–30 m for PAR (euphotic zone). UV attenuation was strongest in the shallow Quempillén estuary, while Fildes Bay (Antarctica) exhibited the highest transparency. Optically non-homogeneous water layers and seasonal variation in transparency (lower in winter) characterized Comau Fjord and Puyuhuapi Channel. In general, multivariate analysis based on Kd values of UV and PAR wavelengths discriminated strongly Quempillén estuary and Puyuhuapi Channel from other study sites. Spatial (horizontal) variation within the estuary of Valdivia river reflected stronger attenuation in zones receiving river impact, while within Fildes Bay a lower spatial variation in water transparency could in general be related to closeness of glaciers, likely due to increased turbidity through ice-driven processes. Higher transparency and deeper UV-B penetration in proportion to UV-A/visible wavelengths observed in Fildes Bay suggests a higher risk for Antarctic ecosystems reflected by e.g. altered UV-B damage vs. photorepair under UV-A/PAR. Considering that damage repair processes often slow down under cool temperatures, adverse UV impact could be further exacerbated by cold temperatures in this location, together with episodes of ozone depletion. Overall, the results emphasize the marked spatial (horizontal and vertical) and temporal heterogeneity of optical characteristics, and challenges that these imply for estimations of underwater optics.