Transfer of cyanobacterial carbon to a higher trophic-level fish community in a eutrophic lake food web: fatty acid and stable isotope analyses
Transfer of cyanobacterial carbon to a higher trophic-level fish community in a eutrophic lake food web: fatty acid and stable isotope analyses
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DOI：
10.1007/s00442-018-4257-5
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发表时间：
2018-11-01
期刊：
影响因子：
2.7
通讯作者：
Miyata, Naoyuki
中科院分区：
文献类型：
--
作者：
Fujibayashi, Megumu;Okano, Kunihiro;Miyata, Naoyuki
鱼类群落对蓝藻碳的膳食利用知之甚少。我们研究了蓝藻碳转移到鱼在富营养化湖泊中使用脂肪酸生物标志物和测量脂肪酸和散装氮的稳定碳同位素比值。本研究共采集了5种鱼类（日本下颏鱼（Hypomesus nipponensis），鲤鱼，Tridentiger brevisspinis和Gymnogobius castaneus）以及2016年6月至11月来自日本八郎湖的悬浮物。8月至10月观察到蓝藻水华。从6月到8月，蓝藻脂肪酸生物标志物（18：26和18：33）仅占这些鱼类总脂肪酸的1.4-4.3%，表明在此期间蓝藻对鱼类饲料的贡献较低。然而，蓝藻脂肪酸生物标志物在这些鱼类中的贡献在9月份急剧增加（10.5-17.1%），除了第二年的H。日本人9月份，这些鱼类的稳定碳同位素比值为18：33，几乎相当于悬浮物中的稳定碳同位素比值，悬浮物主要由蓝藻组成。所收集的鱼类的营养位置范围从1.6到3.4，根据其稳定的氮同位素值，表明一些鱼直接摄入蓝藻，而其他人则通过食物链间接获得蓝藻。这些研究结果表明，蓝藻碳转移到富营养化湖泊生态系统的蓝藻水华的食物链。
The dietary utilization of cyanobacterial carbon by fish communities is poorly understood. We examined the transfer of cyanobacterial carbon to fish in a eutrophic lake using fatty acid biomarkers and measuring the stable carbon isotope ratios of fatty acid and bulk nitrogen. We collected five species of fish (Hypomesus nipponensis, Carassius sp., Cyprinus carpio, Tridentiger brevispinis, and Gymnogobius castaneus) as well as the seston from June to November 2016 from Lake Hachiro, Japan. Cyanobacterial blooms were observed from August to October. From June to August, cyanobacterial fatty acid biomarkers (18:26 and 18:33) accounted for only 1.4-4.3% of total fatty acids in these fish species, indicating a low contribution of cyanobacteria to fish diets during this period. However, the contribution of the cyanobacterial fatty acid biomarkers in these fish species increased sharply in September (10.5-17.1%), except in second-year H. nipponensis. In September, the stable carbon isotope ratios of 18:33 in these fish species were almost equivalent to those in the seston, which was primarily composed of cyanobacteria. The trophic positions of the collected fish species ranged from 1.6 to 3.4, based on their stable nitrogen isotope values, indicating that some fish ingested cyanobacteria directly, while others acquired cyanobacteria indirectly, through the food chain. These findings indicate that cyanobacterial carbon is transferred up the food chain in eutrophic lake ecosystems with cyanobacterial blooms.