Avigliano Esteban, Niklitschek Edwin, Chung Ming-Tsung, Diaz Boris, Chalde Tomás, Di Prinzio Cecilia, Solimano Patricio, Llompart Facundo, Garcés Cristóbal, Diaz Ochoa Javier, Aldea Cristian, Huang Kuo-Fang, Duquenoy Camille, Leisen Mathieu, Volpedo Alejandra
CONICET- Universidad de Buenos Aires, Instituto de Investigaciones en Producción Animal (INPA), Facultad de Ciencias Veterinarias, Av. Chorroarin 280 (C1427CWO), Buenos Aires, Argentina.
Universidad de Los Lagos, Centro i∼mar, Camino a Chinquihue Km.6, Puerto Montt, Región de Los Lagos 5480000, Chile.
Sci Total Environ. 2023 May 15;873:162395. doi: 10.1016/j.scitotenv.2023.162395. Epub 2023 Feb 24.
Patagonian aquatic environments have been invaded since the end of the last century by different species of salmonids. Knowing the natal origin and homing/straying rate of the salmonids in colonised environments is essential to understanding the dispersal mechanisms and developing management plans. In the last two decades, Chinook salmon Oncorhynchus tshawytscha showed the greatest natural dispersal capacity in Patagonia. The main goal of this study was to evaluate the environmental strontium isotope ratio (Sr/Sr) as a potential natural tag to infer the natal origin and ontogenetic habitat use of salmonids in Patagonia, specifically Chinook salmon. Sr/Sr ratio was determined in water samples from 26 sites distributed in 14 Atlantic and Pacific basins in low and high water seasons. Environmental Sr/Sr showed greater spatial than temporal variation, revealing great potential as a tool to infer the natal origin and life history of several migratory fish species in Patagonia. Otolith core-to-edge Sr/Sr profiles were also analysed in 108 Chinook salmon from six basins. A cluster analysis based on the Unweighted Pair Group method (UPGMA) and Euclidean distances without prior classification grouped the sampled rivers into five main groups with significantly different (p < 0.05) isotopic ratios, sometimes integrated basins with different slopes (Atlantic or Pacific). The cluster analysis based on the natal Sr/Sr period in otolith (∼natal origin) showed clear segregation between the Atlantic and Pacific samples. A mismatch between water and otolith natal Sr/Sr ratio was detected in some Atlantic basins (e.g. De las Vueltas River in Santa Cruz Basin) and Pacific (e.g. Liquiñe Basin) and, which could be explained either by straying behaviours or by large geochemical variability between tributaries, within river systems. Our results showed that Sr/Sr is a useful natural tag to trace the life history of migratory fishes in Patagonia, especially for invasive species such as Chinook salmon.
自上世纪末以来，巴塔哥尼亚的水生环境已被不同种类的鲑科鱼类入侵。了解鲑科鱼类在已殖民环境中的出生地以及归巢/偏离率对于理解其扩散机制和制定管理计划至关重要。在过去二十年中，奇努克鲑（Oncorhynchus tshawytscha）在巴塔哥尼亚展现出了最强的自然扩散能力。本研究的主要目标是评估环境锶同位素比率（Sr/Sr）作为一种潜在的天然标记，以推断巴塔哥尼亚鲑科鱼类，特别是奇努克鲑的出生地及个体发育过程中的栖息地利用情况。在低水位和高水位季节，对分布于14个大西洋和太平洋流域的26个地点的水样进行了Sr/Sr比率测定。环境Sr/Sr显示出更大的空间差异而非时间差异，这表明其作为推断巴塔哥尼亚几种洄游鱼类出生地及生活史的工具具有巨大潜力。还对来自六个流域的108条奇努克鲑的耳石核心到边缘的Sr/Sr剖面进行了分析。基于非加权配对组方法（UPGMA）和欧氏距离的聚类分析（无先验分类）将采样河流分为五个主要组，这些组的同位素比率显著不同（p < 0.05），有时还整合了不同坡度的流域（大西洋或太平洋）。基于耳石中出生时的Sr/Sr时期（约出生地）的聚类分析显示，大西洋和太平洋样本之间有明显的分离。在一些大西洋流域（如圣克鲁斯流域的德拉斯韦尔塔斯河）和太平洋流域（如利基内流域）检测到水和耳石出生时的Sr/Sr比率不匹配，这可能是由于偏离行为或河流系统内支流之间巨大的地球化学变异性造成的。我们的结果表明，Sr/Sr是追踪巴塔哥尼亚洄游鱼类生活史的有用天然标记，特别是对于像奇努克鲑这样的入侵物种。
