Temporal and vertical variations of lipid biomarkers during a bottom ice diatom bloom in the Canadian Beaufort Sea: further evidence for the use of the IP25 biomarker as a proxy for spring Arctic sea ice
Temporal and vertical variations of lipid biomarkers during a bottom ice diatom bloom in the Canadian Beaufort Sea: further evidence for the use of the IP25 biomarker as a proxy for spring Arctic sea ice
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DOI：
10.1007/s00300-010-0942-5
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发表时间：
2011-12-01
期刊：
影响因子：
1.7
通讯作者：
Gosselin, Michel
中科院分区：
文献类型：
--
作者：
Brown, Thomas A.;Belt, Simon T.;Gosselin, Michel
海冰硅藻生物标志物的浓度变化，IP 25（冰代理与25个碳原子），测量底部10厘米的海冰收集从东博福特海和阿蒙森湾从2008年1月至6月，作为国际极地年环极缺陷铅系统研究的一部分。IP 25浓度的时间和垂直变化与其他生物标志物和冰藻生产指标进行了比较。从仲冬到早春采集的海冰样本中没有检测到IP 25，这可能是由于藻类生长和积累的光照限制条件。从3月初到6月中旬，IP 25浓度与脂肪酸相关性很好（r = 0.79; P < 0.001），与总甾醇相关性较低（r = 0.63; P < 0.001），与邻近海冰芯的叶绿素a浓度和硅藻细胞丰度定性相关。大约90%的海冰IP 25积累发生在3月中旬至5月下旬，与冰藻水华期一致。大多数人（CA）87-93%）的IP 25在海冰的下部5 cm内生物合成，其中盐水体积分数> 5%，这与盐水通道连通性限制硅藻在海冰内部定殖的假设一致。最大的IP 25浓度发生在1-3厘米的冰-水界面提供了进一步的证据，选择性海冰硅藻起源的生物标志物。相比之下，脂肪酸和甾醇的垂直浓度曲线表明这些生物标志物的混合来源。
Variations in the concentrations of the sea ice diatom biomarker, IP25 (Ice Proxy with 25 carbon atoms), were measured in the bottom 10 cm of sea ice collected from the eastern Beaufort Sea and Amundsen Gulf from January to June 2008, as part of the International Polar Year-Circumpolar Flaw Lead system study. Temporal and vertical changes in IP25 concentrations were compared against other biomarkers and indicators of ice algal production. IP25 was not detected in sea ice samples collected from mid-winter to early spring, likely as a result of light-limiting conditions for algal growth and accumulation. From early March to mid-June, IP25 concentrations correlated well with those of fatty acids (r = 0.79; P < 0.001), less so with total sterols (r = 0.63; P < 0.001) and qualitatively with chlorophyll a concentrations and diatom cell abundances from adjacent sea ice cores. Approximately 90% of the total sea ice IP25 accumulation occurred from mid-March to late-May, coincident with the ice algal bloom period. The majority (ca. 87-93%) of IP25 was biosynthesised within the lower 5 cm of the sea ice where brine volume fractions were > 5% which is consistent with the hypothesis that brine channel connectivity limits the internal colonisation of sea ice by diatoms. Maximum IP25 concentrations occurred at 1-3 cm from the ice-water interface providing further evidence for a selective sea ice diatom origin for this biomarker. In contrast, vertical concentration profiles for fatty acids and sterols indicated mixed sources for these biomarkers.