INVESTIGADORES
BOTTO Florencia
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:
PAULINA MARTINETTO; FLORENCIA BOTTO; OSCAR IRIBARNE
Lugar:
St Johns Canada
Reunión:
Congreso; ASLO Summer Meeting; 2008
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. δ15N
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.