Advanced stable isotope analyses of seabird feathers - ecological segregation and historical changes in trophic levels across four Antarctic and subantarctic seabird communities

海鸟羽毛的高级稳定同位素分析 - 四个南极和亚南极海鸟群落的生态隔离和营养级的历史变化

• 批准号: 313397752
• 负责人: Professorin Dr. Petra Quillfeldt, Ph.D.
• 金额: --
• 依托单位: ArbeitsgruppeTierökologie
• 依托单位国家: 德国
• 项目类别: Infrastructure Priority Programmes
• 财政年份: 2016
• 资助国家: 德国
• 起止时间: 2015-12-31 至 2016-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/313397752?language=en
• 关键词: Advanced; stable; isotope; analyses; seabird

Bulk nitrogen and carbon stable isotope analyses provide a useful tool to investigate ecological segregation within and among species in the marine environment, and can give insights in trophic positions and spatial distribution. However, in many contexts the interpretation of stable isotope values is hampered by a lack of isotopic baseline data. For example, we can now follow even small seabirds such as storm petrels during their year-round movements at sea, and when they moult in distant waters, information on their diet is conserved in their feathers which can then be sampled on land. However, we often cannot obtain diet samples from those distant waters that would provide an isotopic baseline. However, two advanced stable isotope techniques can overcome such shortages: Compound-specific analyses of amino acids (CSIA, proposed in 2002 by McClelland and Montoya) and the analysis of hydrogen stable isotope ratios (HSIA, proposed by Ostrom et al. 2014). CSIA is based on the fact that animals do not change certain essential amino acids (e.g. phenylalanine), while other amino acids change largely between diet and consumer (e.g. glutamic acid). Thus, trophic position can be obtained from the difference in the nitrogen stable isotope values of glutamic acid and phenylalanine. HSIA has been proposed as a tool to distinguish between petrel diets consisting of isosmotic squid and crustaceans and those composed mainly of hyposmotic teleost fish. As salt load differs between isosmotic and hyposmotic diets, isotopic discrimination associated with water loss during salt excretion through salt glands may lead to deuterium-enriched tissues when consuming more isosmotic diets. The aim of the present study is to enhance our understanding of the ecological segregation in seabird communities using these advanced stable isotope analyses. In a comparative community study, we will analyse the trophic structure of four seabird communities from the Antarctic und Sub-Antarctic, with emphasis on small petrels. The study design offers unique possibilities to test hypotheses on the distribution of trophic levels in communities differing in the number of ecologically similar species and among species differing in their distribution (winter distribution ranges from subtropical to polar). Furthermore, we will analyse inter-annual differences and historic changes in the feeding ecology of pelagic petrels in polar waters: We will analyse feathers taken during previous multi-year studies in two petrel species covering several years of different food availability, as well as historical feathers of several species dating back ca. 60-100 years, to investigate changes in trophic levels. This study aligns with the aims of the SPP1158, especially the topics Gateways to lower latitudes - by comparing Antarctic and subantarctic communities - and Response to environmental change - by determining inter-annual and historical changes, and relating them to changes in food availability.

体积氮和碳稳定同位素分析为研究海洋环境中物种内部和物种之间的生态隔离提供了有用的工具，并可以提供营养位置和空间分布的见解。然而，在许多情况下，稳定同位素值的解释由于缺乏同位素基线数据而受到阻碍。例如，我们现在甚至可以跟踪小型海鸟，如风暴海燕全年在海上的活动，当它们在遥远的水域换羽时，它们的饮食信息保存在羽毛中，然后可以在陆地上取样。然而，我们通常无法从那些遥远的水域获得饮食样本，从而提供同位素基线。然而，两种先进的稳定同位素技术可以克服这些不足：氨基酸的化合物特异性分析（CSIA，由McClelland和Montoya于2002年提出）和氢稳定同位素比率分析（HSIA，由Ostrom等人于2014年提出）。CSIA是基于动物不会改变某些必需氨基酸（如苯丙氨酸）的事实，而其他氨基酸在饮食和消费之间变化很大（如谷氨酸）。因此，可以通过谷氨酸和苯丙氨酸氮稳定同位素值的差异来确定营养位置。HSIA已被提出作为区分海燕饮食由等渗鱿鱼和甲壳类动物组成和主要由低渗硬骨鱼组成的工具。由于盐负荷在等渗饮食和低渗饮食之间存在差异，在盐通过盐腺排泄过程中与水分损失相关的同位素差异可能导致在摄入更多等渗饮食时组织富氘。本研究的目的是利用这些先进的稳定同位素分析来提高我们对海鸟群落生态隔离的认识。在一项比较群落研究中，我们将分析来自南极和亚南极的四种海鸟群落的营养结构，重点是小海燕。该研究设计提供了独特的可能性，以检验在生态相似物种数量不同的群落中营养水平分布的假设，以及在其分布不同的物种之间（冬季分布从亚热带到极地）。此外，我们将分析极地水域中上层海燕摄食生态的年际差异和历史变化：我们将分析之前多年研究中两种海燕物种的羽毛，涵盖数年不同的食物供应，以及几个物种的历史羽毛，可追溯到大约60-100年，以调查营养水平的变化。这项研究与SPP1158的目标一致，特别是通过比较南极和亚南极群落进入低纬度地区的主题，以及通过确定年际和历史变化，并将它们与食物供应的变化联系起来，对环境变化的响应。

项目成果

Testing the usefulness of hydrogen and compound-specific stable isotope analyses in seabird feathers: a case study in two sympatric Antarctic storm-petrels

• DOI: 10.1007/s00227-017-3224-8
• 发表时间: 2017-09
• 期刊: Marine Biology
• 影响因子: 2.4
• 作者: P. Quillfeldt;S. Thorn;Benjamin Richter;M. Nabte;N. Coria;J. Masello;M. Massaro;Verónica C Neves