Isotope geochemistry as a natural tag of fish in Patagonian freshwater environments: The invasive Chinook salmon case

AVIGLIANO, ESTEBAN; NIKLITSCHEK, EDWIN; CHUNG, MING-TSUNG; DIAZ, BORIS; CHALDE, TOMÁS; DI PRINZIO, CECILIA; SOLIMANO, PATRICIO; LLOMPART, FACUNDO; GARCÉS, CRISTÓBAL; OCHOA, JAVIER DIAZ; ALDEA, CRISTIAN; HUANG, KUO-FANG; DUQUENOY, CAMILLE; LEISEN, MATHIEU; VOLPEDO, ALEJANDRA

THE SCIENCE OF TOTAL ENVIRONMENT

Elsevier

Año: 2023

0048-9697

Patagonian aquatic environments have been invaded since the end of the last century bydifferent species of salmonids. Knowing the natal origin and homing/straying rate of thesalmonids in colonised environments is essential to understanding the dispersalmechanisms and developing management plans. In the last two decades, Chinook salmonOncorhynchus tshawytscha showed the greatest natural dispersal capacity in Patagonia. Themain goal of this study was to evaluate the environmental strontium isotope ratio (87Sr/86Sr)as a potential natural tag to infer the natal origin and ontogenetic habitat use of salmonids inPatagonia, specifically Chinook salmon. 87Sr/86Sr ratio was determined in water samplesfrom 26 sites distributed in 14 Atlantic and Pacific basins in low and high water seasons.Environmental 87Sr/86Sr showed greater spatial than temporal variation, revealing greatpotential as a tool to infer the natal origin and life history of several migratory fish speciesin Patagonia. Otolith core-to-edge 87Sr/86Sr profiles were also analysed in 108 Chinooksalmon from six basins. A cluster analysis based on the Unweighted Pair Group method(UPGMA) and Euclidean distances without prior classification grouped the sampled riversinto five main groups with significantly different (p