识别来源的方法,运动,动物的觅食区域对于理解生态系统的连通性至关重要,营养流动,和其他生态过程。遥测方法可以提供详细的空间覆盖,但仅限于用于标记的样本的最小体积。近年来,稳定同位素已越来越多地用于通过将景观同位素模式与运动联系起来来跟踪动物的迁移(等地形)。然而,与遥测方法相比,体稳定同位素的空间分辨率较低。这里,我们通过评估来自鱼肝的脂肪酸(δ2HFA和δ13CFA)的化合物特异性氢和碳稳定同位素的使用,研究了一种新颖的方法,肌肉,大脑,和眼睛组织,用于识别254km2亚高山河流流域的位置特异性。我们分析了208条鱼(欧洲牛头,虹鳟鱼,和棕色鳟鱼)于2016年和2018年在15个不同的地点收集。与δ2HFA值相比,这些鱼组织的δ13CFA值彼此之间的相关性更高。δ2HFA和δ13CFA值均显示组织依赖性同位素分馏,而鱼类类群只有很小的影响。最高的位点特异性是δ13CDHA值,而亚油酸和α-亚麻酸之间的δ2H同位素差异导致最高的位点特异性。使用FA同位素值的线性判别分析,超过90%的鱼可以被分配到它们的原产地;然而,当2016年的同位素数据用于预测2018年采集的样品的部位时,准确度下降至约56%,这表明δ2HFA和δ13CFA的部位特异性随时间变化.然而,在此时间间隔内,δ2HFA和δ13CFA的预测能力在单个时间点仍高于大体积组织同位素的位点特异性.总之,脂肪酸的化合物特异性同位素分析可能成为评估动物精细和大规模运动和觅食区域的高效工具。
Methods for identifying origin, movement, and foraging areas of animals are essential for understanding ecosystem connectivity, nutrient flows, and other ecological processes. Telemetric methods can provide detailed spatial coverage but are limited to a minimum body size of specimen for tagging. In recent years, stable isotopes have been increasingly used to track animal migration by linking landscape isotope patterns into movement (isoscapes). However, compared to telemetric methods, the spatial resolution of bulk stable isotopes is low. Here, we examined a novel approach by evaluating the use of compound-specific hydrogen and carbon stable isotopes of fatty acids (δ2HFA and δ13CFA) from fish liver, muscle, brain, and eye tissues for identifying site specificity in a 254 km2 sub-alpine river catchment. We analyzed 208 fish (European bullhead, rainbow trout, and brown trout) collected in 2016 and 2018 at 15 different sites. δ13CFA values of these fish tissues correlated more among each other than those of δ2HFA values. Both δ2HFA and δ13CFA values showed tissue-dependent isotopic fractionation, while fish taxa had only small effects. The highest site specificity was for δ13CDHA values, while the δ2H isotopic difference between linoleic acid and alpha-linolenic acid resulted in the highest site specificity. Using linear discrimination analysis of FA isotope values, over 90% of fish could be assigned to their location of origin; however, the accuracy dropped to about 56% when isotope data from 2016 were used to predict the sites for samples collected in 2018, suggesting temporal shifts in site specificity of δ2HFA and δ13CFA. However, the predictive power of δ2HFA and δ13CFA over this time interval was still higher than site specificity of bulk tissue isotopes for a single time point. In summary, compound-specific isotope analysis of fatty acids may become a highly effective tool for assessing fine and large-scale movement and foraging areas of animals.