Strontium isotope ratios (87Sr/86Sr) and 18 trace element concentrations were measured in the water and in the otoliths of an anadromous catfish, Pangasius krempfi, to infer its natal origin and potential migration pathways. Water was sampled at 18 locations along the mainstream, tributaries and distributaries of the Mekong River. To check for accuracy and precision, measurements of the 87Sr/86Sr ratios and trace element concentrations were then compared in two laboratories that use different analytical methods. Differences in trace element concentrations between locations were not significant and could not, therefore, be used to discriminate between migration pathways. However, the Mekong mainstream, tributaries and distributaries could all be discriminated using Sr isotopes.
Trong Tran, N., M. Labonne, M. Chung, C. Wang, K. Huang, J. Durand, C. Grudpan, B. Chan, H.D. Hoang, and J. Panfili
10 June 2021
Otolith, Trace elements, Animal migration, Salinity, Fish physiology, Fresh water, Sea water, Spawning