PERSONAL DE APOYO
SERRA Analia Veronica
congresos y reuniones científicas
Título:
Carbon biogeochemical cycling from an isotopic standpoint: the role of fishes in estuarine saltmarshes
Autor/es:
LA COLLA, NOELIA SOLEDAD; FRANCO, MARCOS; BOTTÉ, SANDRA ELIZABETH; NEGRIN, VANESA LORENA; SERRA, ANALÍA VERÓNICA; GOMES DE ALMEIDA, MARCELO; REZENDE, CARLOS; MARCOVECCHIO, JORGE
Lugar:
Puerto Madryn
Reunión:
Congreso; IV Reunión Argentina de Geoquímica de la Superficie; 2016
Institución organizadora:
FACULTAD DE CIENCIAS NATURALES UNIVERSIDAD NACIONAL DE LA PATAGONIA SAN JUAN BOSCO
Resumen:
Within coastal environments, estuaries are important regions for studying transferences from land- margin to margin-open ocean. Saltmarshes within estuaries are known to function as nursery areas for many fish and invertebrate species. Interactions in these environments influence the biogeochemical cycling of elements in estuaries, where fish could play an important role in exporting the productivity to the open sea (1). Stable isotopes (δ13C and δ15N) have been used to obtain information on the sources of organic matter in estuaries andits application is based on the premise that different sources have distinct isotope signatures (2). The lack of direct grazing on marsh vegetation and abundance of dead plant material and other organic matter in sediments of estuaries implies that detritus is one of the principal inputs at the base of estuarine food-webs (3). The present study evaluates the hypothesis thatconsumers might reflect assimilation of material from different origins and might act as a good estimator of the carbon/energy transference pathways. A mixing model based on the δ13C and δ15N values of possible ?sources? (i.e.: sediment, salt marsh vegetation, microbial mats and juvenile fish species) and adult fish species Cynoscion guatucupa, Mustelus schmitti, Micropogonias furnieri and Brevoortia aurea as ?consumers? was developed with SIAR (Stable Isotope Analysis in R). The study revealed the relative importance ofsaltmarshes of Sarcocornia perennis (mean δ13C: -26,2 ?) as contributor to the isotopic signature of B. aurea (mean δ13C: -18.2 ?). Also Spartina alterniflora (mean δ13C: - 13,9 ?) as well as the juveniles of the fish species, added as preys, were the major contributors to the isotopic values of C. guatucupa (mean δ13C: -14,8 ?). These results highlight the differential sources of organic carbon to the estuary. Further research is needed to achieve a better assessment of the biogeochemical processes taking place.