Otolith chemical composition as a useful tool for sciaenids stock discrimination in Southwestern Atlantic

A. VOLPEDO; A. FERNANDEZ CIRELLI

SCIENTIA MARINA

Institut de Ciències del Mar de Barcelona

Lugar: Barcelona; Año: 2006 vol. 70 p. 325 - 334

0214-8358

Stripped weakfish (Cynoscion guatucupa) and whitemouth croaker (Micropogonias furnieri) are important commercia l and recreational species abundant along the South America Atlantic coast. Otolith chemical composition as a tool for identification of fish stocks has being used in recent years for several species. C. guatucupa and M. furnieri otolith chemical  composition were determined by inductively coupled plasma- optical emission spectrometry (ICP-OES) in samples from coastal sites (Partido de La Costa, Mar del Plata and San Blás Bay). Significant different Mg/Ca, Mn/Ca and Sr/Ca ratios of C. guatucupa and Cd/Ca, Cu/Ca, Mg/Ca, Sr/Ca and Zn/Ca ratios of M. furnieri suggest the existence of two different fish stocks, one originated in the north (including Samborombón Bay and Partido de La Costa fisheries) and another stock originated in the south (including "El Rincón" and San Blás fisheries). These results agree with previous studies using different methodologies. These stocks may be separated by an oceanographic barrier, "El Rincón" front. Otolith chemical composition has not been previous used in South America for the identification of fish stocks and may be a simple, quick and useful tool for sustainable exploitation and management of commercial species.