...
  • 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>ICES Journal of Marine Science >The pelagic foodweb in the upwelling ecosystem of Galicia (NW Spain) during spring: natural abundance of stable carbon and nitrogen isotopes
【24h】

The pelagic foodweb in the upwelling ecosystem of Galicia (NW Spain) during spring: natural abundance of stable carbon and nitrogen isotopes

机译：春季加利西亚（西班牙西北部）上升生态系统中的上层食物网：稳定的碳和氮同位素的自然丰度

获取原文
获取原文并翻译 | 示例
           
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

The structure of the pelagic foodweb in the upwelling ecosystem of Galicia (NW Spain) was studied by means of the enrichment in ~(13)C and ~(15)N isotopes in plankton (four size classes from 20 to >1000 μm), sardine (primary consumer) and dolphin (top consumer). Samples were collected in March 1998, during the spawning period of sardines at the beginning of the upwelling season. Isotopic enrichment across plankton size classes was lower than either enrichment between plankton and sardine or enrichment between sardine and dolphin. This difference may be attributed to the presence of chain-forming phytoplankton in some plankton size classes but also to a large degree of omnivory among zooplankton. Also, there was a size-dependent effect on ~(15)N enrichment of sardine. Sardines < 18 cm had a variable isotopic enrichment but generally higher than those of larger sardines, revealing omnivorous but mostly zoophagous diets. In contrast, sardines ≥18 cm showed a linear decrease of ~(15)N enrichment with length, as a consequence of the increase in the efficiency of filter-feeding and in the amount of phytoplankton ingested. According to ~(15)N enrichment, we concluded that probably there are no more than four trophic levels in the studied ecosystem. Nevertheless, our results revealed that the pelagic food web in this upwelling area is more complex than expected due to the generalized omnivory in all organisms. Furthermore, the obtained relationships between δ~(15)N and the size of organisms provide the basis for a quantitative analysis of changes in the trophic structure of this ecosystem.
机译：通过对浮游生物中〜（13）C和〜（15）N同位素的富集（从20到> 1000μm的四种大小分类），研究了加利西亚（西班牙西北部）上升生态系统中的上层食物网的结构，沙丁鱼（主要消费者）和海豚（主要消费者）。在上升季节开始时，在沙丁鱼产卵期的1998年3月收集了样品。浮游生物大小类别之间的同位素富集低于浮游生物和沙丁鱼之间的富集或沙丁鱼和海豚之间的富集。这种差异可能归因于某些浮游生物大小类别中链形成浮游植物的存在，也归因于浮游动物之间的杂食性。另外，沙丁鱼的〜（15）N富集具有大小依赖性。小于18 cm的沙丁鱼的同位素富集程度可变，但通常高于较大沙丁鱼的同位素富集，显示杂食性但大部分为食虫性饮食。相比之下，沙丁鱼≥18cm则随着长度增加，〜（15）N富集量呈线性下降，这是由于滤食喂养效率的提高和浮游植物摄食量的增加所致。根据〜（15）N富集，我们得出结论，在所研究的生态系统中，营养级别可能不超过四个。但是，我们的结果表明，由于所有生物体中的杂食性，该上升流区的中上层食物网比预期的要复杂。此外，所获得的δ〜（15）N与生物体大小之间的关系为定量分析该生态系统的营养结构提供了基础。

著录项

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号