Influence of environmental gradients on C and N stable isotope ratios in coral reef biota of the Red Sea, Saudi Arabia
Influence of environmental gradients on C and N stable isotope ratios in coral reef biota of the Red Sea, Saudi Arabia
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DOI：
10.1016/j.seares.2013.07.008
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发表时间：
2014-01-01
影响因子：
2
通讯作者：
Sommer, Ulrich
中科院分区：
文献类型：
--
作者：
Kuerten, Benjamin;Al-Aidaroos, Ali M.;Sommer, Ulrich
红海具有水温、营养物和叶绿素a浓度自北向南逐渐升高的自然环境梯度。本研究的目的是通过碳（δ C-13）和氮（δ N-15）稳定同位素来评估生态水文、颗粒有机质（POM）和珊瑚礁生物群之间的关系。草食性、浮游性和食肉性鱼类、浮游动物、软珊瑚（藻科）和双壳类（鳞砗磲）被先验地定义为生物群行业。环境样本（营养物、叶绿素a）、海洋学数据（盐度、温度）、POM和生物群在北纬28度31分至16度31分之间的8个珊瑚礁上收集。行会的同位素生态位在三角洲C-13和三角洲N-15同位素生态位空间中分离，并在纬度尺度上与环境因子显著相关。使用贝叶斯同位素混合模型SIAR估计了饲料端元的贡献。在红海中部工业化地区，POM和浮游动物N-15的富集表明受到城市径流的影响。三角洲N-15及其相对营养位置（RTPs）都有向南增加的趋势，但城市径流抵消了红海中部地区向更高三角洲N-15的自然环境梯度。和rtp。研究表明，红海珊瑚礁的消费型δ C-13和δ N-15主要受纬度环境梯度和局地城市径流的影响。这项研究说明了生态水文在解释红海珊瑚礁稳定同位素的营养关系时的重要性。(C) 2013 Elsevier B.V.版权所有
The Red Sea features a natural environmental gradient characterized by increasing water temperature, nutrient and chlorophyll a concentrations from North to South. The aim of this study was to assess the relationships between ecohydrography, particulate organic matter (POM) and coral reef biota that are poorly understood by means of carbon (delta C-13) and nitrogen (delta N-15) stable isotopes. Herbivorous, planktivorous and carnivorous fishes, zooplankton, soft corals (Alcyonidae), and bivalves (Tridacna squamosa) were a priori defined as biota guilds. Environmental samples (nutrients, chlorophyll a), oceanographic data (salinity, temperature), POM and biota were collected at eight coral reefs between 28 degrees 31'N and 16 degrees 31'N. Isotopic niches of guilds separated in delta C-13 and delta N-15 isotopic niche spaces and were significantly correlated with environmental factors at latitudinal scale. Dietary end member contributions were estimated using the Bayesian isotope mixing model SIAR. POM and zooplankton N-15 enrichment suggested influences by urban run-off in the industrialized central region of the Red Sea. Both delta N-15 and their relative trophic positions (RTPs) tend to increase southwards, but urban runoff offsets the natural environmental gradient in the central region of the Red Sea toward higher delta N-15.and RTPs. The present study reveals that consumer delta C-13 and delta N-15 in Red Sea coral reefs are influenced primarily by the latitudinal environmental gradient and localized urban runoff. This study illustrates the importance of ecohydrography when interpreting trophic relationships from stable isotopes in Red Sea coral reefs. (C) 2013 Elsevier B.V. All rights reserved.