INVESTIGADORES
VOLPEDO Alejandra Vanina
congresos y reuniones científicas
Título:
Application of the morphology, morphometry and chemical composition of the otolith for identification of stocks of commercial fishes
Autor/es:
VOLPEDO A. V.; AVIGLIANO E; CALLICÓ FORTUNATO R; THOMPSON GA; FERNÁNDEZ CIRELLI , A
Lugar:
Buenos Aires
Reunión:
Taller; Taller Adaptación al Cambio Climático en Sectores Clave en América del Sur, Programa Interdisciplinario de la Universidad de Buenos Aires sobre Cambio Climático (PIUBACC), Internacional; 2012
Institución organizadora:
rograma Interdisciplinario de la Universidad de Buenos Aires sobre Cambio Climático (PIUBACC), Internacional, y IPPC
Resumen:
One of the key tools for an eco-systematical and adaptative fishing management is the determination of fish stocks. Even though there are several traditional techniques used to determine fishing stocks (such as: age structure, parasites identification, genetic determination), in the last decades the application of otoliths has become a very efficient tool. The otoliths are calcareous structures located in the inner ear of fishes and are associated to hearing and equilibriom. Its morphology is specific for each species so otoliths are used to determine prey items in stomach contents and their morphology is related to fish size. It has been determined in recent studies that the chemical composition of the otolith mainly reflects the chemical composition of the water. As there are certain relations among water elements. (e.g. Sr:Ca, Ba:Ca) that have co-relation with salinity and temperature, it is feasible that such relations are also present in the otoliths allowing to determine fish movements , between areas of different salinity and temperature. This paper presents a revision of otolith applications in the determination of stocks of freshwater and marine commercial fishes. The freshwater species studied in the Cuenca del Plata is the silverside fish (Odontesthes bonariensis) and the species of the coast of the Southwestern Atlantic are the Brazilian flathead (Percophis brasiliensis), the Whitemouth croaker (Micropogonias furnieri) and the Stripped weakfish (Cynoscion guatucupa). Samples of water and fishes were taken. silverside fishes were captured in different areas of the inferior part of Cuenca del Plata (Delta del Paraná and Berisso), and in some other located in the Pampa region. The rest of the species came from different areas of the marine coast (Common fishing area Argentina-Uruguay, Partido de la Costa, Mar del Plata and San Blás). The otolith morphologic pattern was also studied as well as the morphometry of the silverside fish, the Whitemouth croaker and the Stripped weakfishes using otoliths morphometric indexes vs. fish size so as to be able to analyze intraspecific similarities and differences for each species. The concentration of different trace elements (Sr, Ba, Zn, Mn) in otoliths and water was also determined by standardized methods using inductively coupled plasma optical emission spectroscopy (ICP-OES); and Ca determination was obtained by titration with EDTA. Results obtained show that otoliths are a useful tool to determine fish stocks of Odontesthes bonariensis,  Percophis brasiliensis, Micropogonias furnieri y Cynoscion guatucupa  in the areas under study. Besides, possible inter-connections of stocks and hypothesis of species deplacement were also proposed.