Identification of the sea ice diatom biomarker IP25 in Arctic benthic macrofauna: direct evidence for a sea ice diatom diet in Arctic heterotrophs
Identification of the sea ice diatom biomarker IP25 in Arctic benthic macrofauna: direct evidence for a sea ice diatom diet in Arctic heterotrophs
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DOI：
10.1007/s00300-011-1045-7
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发表时间：
2012-01-01
期刊：
影响因子：
1.7
通讯作者：
Belt, Simon T.
中科院分区：
文献类型：
--
作者：
Brown, Thomas A.;Belt, Simon T.
目前，北极季节性海冰面积的减少对极地食物网的影响仍不确定。以前，已经采用了一系列替代技术来确定海冰或浮游植物初级生产与北极海洋食物网之间的联系，尽管人们普遍认为这些方法有其局限性。在这里，我们提出了一种利用海冰硅藻生物标志物IP25通过北极食物网追踪海冰初级生产的新方法。2008年3月至5月，作为国际极地年-环极缺陷铅系统研究的一部分，在加拿大北极阿蒙森湾的富兰克林湾收集了各种底栖大型动物标本。对每个标本进行了海冰硅藻生物标志物IP25的分析，以提供底栖生物以海冰藻类为食的证据。在分析的21个标本中，有19个发现了IP25，通常是检测到的高度分支的类异戊二烯生物标志物中最丰富的。海胆（Strongylocentrotus sp.）标本中IP25的稳定同位素组成（δ C-13 = -17.1 +/- A 0.5℃）与北极海冰、沉积颗粒和沉积物中该生物标志物的稳定同位素组成相似。因此，在北极底栖大型动物中检测IP25为提供以海冰藻类为食的令人信服的证据提供了新的途径。研究人员还提出，IP25的分析可能用于追踪未来北极食物网中海冰藻类衍生有机物的营养转移。
Currently, the impact of declining seasonal sea ice extent in the Arctic on polar food webs remains uncertain. Previously, a range of proxy techniques has been employed to determine links between sea ice or phytoplankton primary production and the Arctic marine food web, although it is accepted that such approaches have their limitations. Here, we propose a novel approach to tracing sea ice primary production through Arctic food webs using the sea ice diatom biomarker, IP25. Various benthic macrofaunal specimens were collected between March and May 2008 from Franklin Bay in the Amundsen Gulf, Arctic Canada, as part of the International Polar Year-Circumpolar Flaw Lead system study. Each specimen was analysed for the presence of the sea ice diatom biomarker IP25 in order to provide evidence for feeding by benthic organisms on sea ice algae. IP25 was found in nineteen out of the twenty-one specimens analysed, often as the most abundant of the highly branched isoprenoid biomarkers detected. The stable isotope composition of IP25 (delta C-13 = -17.1 +/- A 0.5aEuro degrees) in the sea urchin (Strongylocentrotus sp.) specimens was similar to that reported previously for this biomarker in Arctic sea ice, sedimenting particles and sediments. It is concluded that detection of IP25 in Arctic benthic macrofauna represents a novel approach to providing convincing evidence for feeding on sea ice algae. It is also proposed that analysis of IP25 may be used to trace trophic transfer of sea ice algal-derived organic matter through Arctic food webs in the future.