INVESTIGADORES
MARTINETTO Paulina Maria Del Rosario
congresos y reuniones científicas
Título:
The relative contribution of marine and land-derived nutrient sources in coastal food webs of Mar Chiquita coastal lagoon area, Argentina
Autor/es:
MARTINETTO PAULINA; FLORENCIA BOTTO; IRIBARNE OSCAR
Lugar:
St. John's, Newfoundland
Reunión:
Congreso; ASLO Summer Meeting 2008; 2008
Institución organizadora:
American Society of Limnology and Oceanography
Resumen:
Shifts in nutrients availability often lead to modifications in the species composition and abundances with potential alteration of the food web. The watershed associated to Mar Chiquita coastal lagoon is affected by intensive agricultural activity and by a small summer tourist village. If nutrients from land are incorporated into the food web is unknown. We used N and C isotopic signatures of primary producers from fresh-water contributors and from coastal adjacent areas to determine marine and land-derived nutrients in the food web. We also determined isotopic signatures in organisms collected in these sites from both the benthos and the water column.  ä15N in primary producers showed differences among sites and trophic steps but did not show a linear trend from land to coast. Signatures of benthos-associated organisms and fishes inside the lagoon showed variations coupled to the specific signatures of producers collected in each site. POM and zooplankton also showed coupling to site but no between benthic and water column components. These results indicate that in this system the contribution of nutrients has local effect with low interchange among sites.