Use of otolith strontium: calcium and zinc: calcium ratios as an indicator of the habitat of Percophis brasiliensis Quoy & Gaimard, 1825 in the southwestern Atlantic Ocean

We evaluate the simultaneous use of Sr: Ca and Zn: Ca ratios of the sagitta otolith as a potential indicator of the habitat of Percophis brasiliensis along a latitudinal gradient in the southwestern Atlantic Ocean (34-42 degrees S and 51-67 degrees W), in order to reliably identify fish stocks. Fish were collected in three sampling sites: Argentine-Uruguayan Common Fishing Zone (AUCFZ), El Rincon (ER) and San Matias Gulf (SMG). The otolith Sr: Ca and Zn: Ca ratios were determined by ICP-OES and EDTA volumetric method. The otolith Sr: Ca ratio was similar in the three sampling sites, while the Zn: Ca ratio was significantly higher in AUCFZ than in ER and SMG for all age groups. The discriminant analysis showed an association between the otolith Sr: Ca and Zn: Ca ratios from ER and SMG. Present results suggest the potential occurrence of two fish stocks of P. brasiliensis in the study area.