INVESTIGADORES
BIANCALANA florencia
congresos y reuniones científicas
Título:
Grazing pressure of mesozooplankton under anthropogenic impact in Ushuaia Bay, Argentina
Autor/es:
DIODATO, S. L.; HOFFMEYER, M. S.; BIANCALANA, F.
Lugar:
Berlín, Alemania.
Reunión:
Conferencia; ICES CIEM, ICES Annual Science Conference; 2009
Institución organizadora:
ICES
Resumen:
ICES CM 2009/P:09
Grazing pressure of mesozooplankton under anthropogenic impact in Ushuaia Bay, Argentina
Soledad Lorena Diodato, Mónica Susana Hoffmeyer, and Florencia Biancalana Ushuaia Bay (on the north coast of the Beagle Channel, Argentina) is under threat of incipient
ecological damage because of discharge of pollutants (sewage and industrial effluents, hydrocarbons, and urban wastes). As coastal zooplankton tolerate environmental stress and respond quickly to anthropogenic changes, they are excellent indicators of ecosystem health. Feeding is a key issue in the study of trophic interactions. The purpose of this work was to assess the grazing impact of mesozooplankton in two regions of Ushuaia Bay with different anthropogenic pressures: a polluted coastal station (CS) and unpolluted external station (ES), in summer. Grazing experiments were performed using mesozooplankton grazers and natural food <100 µm (phytoplankton and microzooplankton). Individual and community feeding rates were estimated for each food fraction after 24-h incubation using the particle removal method. Prey and grazers were qualitatively and quantitatively analysed, yielding results in terms of abundance and carbon. Differences in mesozooplankton composition between the stations were observed. The predominance of copepods such as Oithona similis, Acartia tonsa, and Eurytemora americana, and Podon leuckarti was recorded in CS. Nauplii and copepodids of herbivorous calanoids were dominant in ES. The different values obtained from feeding rates demonstrate the importance of the type and amount of food available, and of the concentration and diversity of grazers, and suggest the existence of two trophic subsystems: one associated with benthopelagic coupling maintained by Macrocystis prairies in the coastal zone and another more related to Beagle Channel plankton in cleaner waters on the outskirts of Ushuaia Bay.
Keywords: grazing, mesozooplankton, anthropogenic pressure, Ushuaia Bay. Contact author: Soledad Lorena Diodato, Centro Austral de Investigaciones Científicas (CONICET), B. Houssay
200, V9410CAB, Ushuaia, Tierra del Fuego, Argentina [e-mail: sole22diodato@yahoo.com.ar].
200, V9410CAB, Ushuaia, Tierra del Fuego, Argentina [e-mail: sole22diodato@yahoo.com.ar].
200, V9410CAB, Ushuaia, Tierra del Fuego, Argentina [e-mail: sole22diodato@yahoo.com.ar].
200, V9410CAB, Ushuaia, Tierra del Fuego, Argentina [e-mail: sole22diodato@yahoo.com.ar].