INVESTIGADORES
FANJUL maria eugenia
congresos y reuniones científicas
Título:
Effect of the invasive reef-building polychaeta Ficopomatus enigmaticus on phytoplankton community in a SW Atlantic coastal lagoon.
Autor/es:
BRUSCHETTI, MARTIN; ROSENTHAL, ALAN; FANJUL, EUGENIA; LUPPI, TOMAS; IRIBARNE, OSCAR
Lugar:
Mérida
Reunión:
Congreso; The Ecological Society of America - Ecology in an Era of Globalization; 2006
Resumen:
Ficopomatus enigmaticus (Polychaeta: Serpulidae), is an invasive reef-building species that has been introduced in the Mar Chiquita coastal lagoon (South-Western Atlantic, Argentina) in the seventies. Its introduction and posterior distribution, notoriously important and unique for the region, have generated great changes in the ecological and sedimentary dynamics of the lagoon, affecting negatively other macroinfaunal species. During the last 24 years, reefs have increased in density (24.3%) and in size (66.8%), encompassing the 86% of the lagoon (ca. 46 km2). Up to date, a few positive effects on ecosystem dynamic have been reported for this invasive specie. Eutrophication in shallow coastal areas, like estuaries, is known to lead an increase in phytoplankton biomass causing alterations in trophic relations and biological structure of those ecosystems. The use of soils for farming and continental runoff of the adjacent terrestrial systems seemed to be a significant nutrient source for this water body. Nevertheless, the lagoon shows a low eutrophic condition. Several invasive species have been reported as regulators of the phytoplankton biomass at eutrophic lagoons. F.enigmaticus could be another example. In order to evaluate this hypothesis an experiment with mesocosms were performed. The experiments consisted in ten treatments with reefs and ten without reefs (controls) in an area inhabited with F. enigmaticus. Samples waters were obtained in order to determinate Chla concentration and total suspended particles. A decreased of 4 magnitude order in Chla concentration in mesocosms with reefs where recorded at twenty days at the beginning of the experiment. In addition a decrease in total suspended particles was found. Other authors founded that physical effects exerted by the reefs altered both the bedload sediment transport and the water flow around them increased the water turbidity. Contrary, this work shows that biological effects (filtration activity) decreased the total suspended particles. Considering the expansion and impact of reefs, and the continuous nutrients supply that arrives of the lagoon, the control on phytoplankton community must be an important factor of control.