Mapping the environmental strontium isotopic ratio in South America to reveal the life history of freshwater fishes

AVIGLIANO, E.; CHUNG, MING-TSUNG; MARC POUILLY; HUANG, KUO-FANG; CASALINUOVO, MIGUEL; DOMININO, JAEL; NATALIA SILVA; SÁNCHEZ, SEBASTIÁN; FACETTI, J.F.; CLAVIJO, C.; ANA MÉNDEZ; JORGE PISONERO; PABLO SCARABOTTI; CAFFETTI, J.D.; ALEJANDRA V. VOLPEDO

Simposio; 7th International Otolith Symposium; 2023

IFOP-Chile y Pontificia Universidad Catolica de Valparaiso

The 87Sr/86Sr isotope ratio has turned out to be a useful natutal tag in freshwater fishes to reveal migratory patterns in environments with geological heterogeneity. Here, we map the environmental 87Sr/86Sr ratio in 15 Atlantic and Pacific basins of South America (Argentina, Brazil, Chile, Paraguay and Uruguay), incorporating novel and recently published data from 84 sampling sites. In the vast La Plata Basin (3,170,000 km2, Argentina, Brazil, Paraguay and Uruguay), 7 areas with different isotopic ratios have been discriminated (0.7083-0.7230), while in Patagonia (Argentina and Chile) 7 groups of basins have been discriminated (0.7045-0.7240). In the vast La Plata Basin, temporal variation was evaluated using invasive bivalve shell (Limnoperna fortunei) as 87Sr/86Sr biomonitors. Significant positive linear relationships were found between shell edge and water for 87Sr/86Sr (relationship 1:1, R2=0.96-0.97, p