Temporal dynamics in a shallow coastal benthic food web: Insights from fatty acid biomarkers and their stable isotopes
Temporal dynamics in a shallow coastal benthic food web: Insights from fatty acid biomarkers and their stable isotopes
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DOI：
10.1016/j.marenvres.2015.04.010
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发表时间：
2015-07-01
影响因子：
3.3
通讯作者：
Vanaverbeke, Jan
中科院分区：
文献类型：
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作者：
Braeckman, Ulrike;Provoost, Pieter;Vanaverbeke, Jan
我们通过脂肪酸（FA）生物标记和化合物特异性稳定同位素分析（CSIA）研究了北海南湾沉积地点的底栖类群饮食中的中上层和底栖食物来源的时间变化。这些类群是非选择性沉积物取食线虫（Sabatieria spp.和“其他线虫”），以及三种主要的大型底栖物种：两种真正的悬浮沉积物取食动物（双壳类 Abra alba 和管栖多毛类 Owenia fuszformis）和疑似捕食性泥栖海葵 Sagartia sp.。这些物种平均占该地区 Abra alba-Kurtiella bidentata 群落生物量的 16% (Abra alba)、17% (Sagartia sp.) 和 20% (Owenia fusiformis)。从细胞计数推断，水柱悬浮颗粒物中的浮游植物动态、叶绿素-a 和有机碳含量在沉积物和动物 FA 丰度中也清晰可见，而沉积物 FA 组成中的植物碎屑动态则不太清楚，可能是由于大型动物对 FA 的斑块分布或剥离所致。线虫似乎主要从沉积环境中吸收多不饱和脂肪酸（PUFA），并进一步从沉积的植物碎屑中非选择性地积累更多（Sabatieria spp.）或更少（“其他线虫”）FA。相比之下，Abra alba FA 组成与以硅藻为主的饮食一致，并且在 Owenia fuszformis 中观察到了褐囊藻的消耗，而 Sagartia sp. 则消耗了褐囊藻。显示出掠夺行为的证据。虽然 Owenia fusiformis 的总 FA 含量全年保持恒定，但 Sagartia sp.由于浮游植物水华的有机物沉积，Abra alba 的 FA 水平增加了一倍以上，其 FA 水平增加了 10 倍以上。由此得出的结论是，非选择性沉积物摄食线虫和悬浮沉积物摄食大型底栖生物之间不存在资源分配，这表明它们属于底栖食物网的不同部分。 (C) 2015 Elsevier Ltd. 保留所有权利。
We investigated the temporal variation of pelagic and benthic food sources in the diet of benthic taxa at a depositional site in the Southern Bight of the North Sea by means of fatty acid (FA) biomarkers and compound-specific stable isotope analysis (CSIA). The taxa were the non-selective deposit feeding nematodes (Sabatieria spp. and 'other nematodes'), and three dominant macrobenthic species: two true suspension-deposit feeders (the bivalve Abra alba and the tube dwelling polychaete Owenia fuszformis) and the suspected predatory mud-dwelling anemone Sagartia sp. These species make up on average 16% (Abra alba), 17% (Sagartia sp.) and 20% (Owenia fusiformis) of the biomass in the Abra alba-Kurtiella bidentata community in this area. Phytoplankton dynamics in the suspended particulate matter of the water column as inferred from cell counts, chlorophyll-a and organic carbon content were clearly visible in sediment and animal FA abundance as well, whereas phytodetritus dynamics in the sediment FA composition were less clear, probably due to patchy distribution or stripping of FA by macrofauna. Nematodes appeared to assimilate mainly Polyunsaturated Fatty Acids (PUFAs) from their sedimentary environment and were further non-selectively accumulating more (Sabatieria spp.) or less ('other nematodes') FA from the deposited phytodetritus. In contrast, Abra alba FA composition was consistent with a diatom-dominated diet and consumption of Phaeocystis was observed in Owenia fuszformis, whereas Sagartia sp. showed evidence of a predatory behaviour. While the total FA content in Owenia fusiformis remained constant throughout the year, Sagartia sp. doubled and Abra alba increased its FA level more than 10-fold in response to the organic matter deposition from the phytoplankton bloom. This leads to the conclusion that there is no resource partitioning between non-selective deposit feeding nematodes and the suspension-deposit feeding macrobenthic organisms, suggesting they belong to separate parts of the benthic food web. (C) 2015 Elsevier Ltd. All rights reserved.