Tracing basal resource use across sea‐ice, pelagic, and benthic habitats in the early Arctic spring food web with essential amino acid carbon isotopes
Tracing basal resource use across sea‐ice, pelagic, and benthic habitats in the early Arctic spring food web with essential amino acid carbon isotopes
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DOI：
10.1002/lno.12315
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发表时间：
2023-02
影响因子：
4.5
通讯作者：
K. Vane;M. Cobain;C. Trueman;T. Vonnahme;S. Rokitta;N. Polunin;H. Flores
中科院分区：
文献类型：
--
作者：
K. Vane;M. Cobain;C. Trueman;T. Vonnahme;S. Rokitta;N. Polunin;H. Flores
北冰洋迅速变暖和相关的海冰减少导致海冰原生生物群落发生变化，影响冰下，远洋和底栖动物的生产力。由于缺乏适合通过食物网追踪特定基础资源（初级生产者和微生物）的生物标志物，对这种影响进行量化受到阻碍。我们研究了必需氨基酸（EAA）的δ 13 C值（δ 13 CEAA值）的潜力，以估计冰下生物（Aperusa glacialis），浮游生物（Calanus hyperboreus）和底栖生物（海绵，海参）以及冷冻浮游鱼类Boreogadus色达对各种基础资源的比例利用。采用了两种方法：基线δ13CEAA值，即基础资源特定δ13CEAA值，和δ13CEAA指纹，或平均中心基线δ13CEAA值。所有研究的生物都大量使用冰下藻类北极直链藻，这表明它在北极食物网中的作用比以前认识到的要大。此外，来自藻类相关细菌的δ13CEAA指纹被清楚地追踪到海绵，海参使用的海带个体可变。虽然A. glacialis，C. hyperboreus和B.色达组织与微藻资源一致，但它们并不完全由构成春季硅藻为主的藻类群落的过滤的远洋和海冰颗粒有机物代表。冰下和浮游微藻的使用只能用基线δ13CEAA值来区分，因为两种栖息地都有类似的微藻分支。我们认为，δ 13 CEAA指纹结合微藻基线δ 13 CEAA值是一个有见地的工具，以评估北极基础资源的持续变化对生物体利用的影响。
A rapidly warming Arctic Ocean and associated sea‐ice decline is resulting in changing sea‐ice protist communities, affecting productivity of under‐ice, pelagic, and benthic fauna. Quantifying such effects is hampered by a lack of biomarkers suitable for tracing specific basal resources (primary producers and microorganisms) through food webs. We investigate the potential of δ13C values of essential amino acids (EAAs) (δ13CEAA values) to estimate the proportional use of diverse basal resources by organisms from the under‐ice (Apherusa glacialis), pelagic (Calanus hyperboreus) and benthic habitats (sponges, sea cucumber), and the cryo‐pelagic fish Boreogadus saida. Two approaches were used: baseline δ13CEAA values, that is, the basal resource specific δ13CEAA values, and δ13CEAA fingerprints, or mean‐centred baseline δ13CEAA values. Substantial use of sub‐ice algae Melosira arctica by all studied organisms suggests that its role within Arctic food webs is greater than previously recognized. In addition, δ13CEAA fingerprints from algae‐associated bacteria were clearly traced to the sponges, with an individually variable kelp use by sea cucumbers. Although mean‐centred δ13CEAA values in A. glacialis, C. hyperboreus, and B. saida tissues were aligned with microalgae resources, they were not fully represented by the filtered pelagic‐ and sea‐ice particulate organic matter constituting the spring diatom‐dominated algal community. Under‐ice and pelagic microalgae use could only be differentiated with baseline δ13CEAA values as similar microalgae clades occur in both habitats. We suggest that δ13CEAA fingerprints combined with microalgae baseline δ13CEAA values are an insightful tool to assess the effect of ongoing changes in Arctic basal resources on their use by organisms.