Plankton features vs environmental quality in the inner zone of Bahía Blanca Estuary (Argentina)

HOFFMEYER, M. S.; BARRÍA DE CAO, M. S.; BERASATEGUI, A. A.; PETTIGROSO, R.; LOPÉZ ABATE, M. C.; BIANCALANA, F.; FULCO, V. K.; FERNÁNDEZ SEVERINI M. D.; MENÉNDEZ M. C.; BERNECH BIELSA, G.; CHAZRRETA, J.

Liverpool, Gran Bretaña

Simposio; EMBS 44, European Marine Biology Symposium; 2009

University of Liverpool

44th EMBS 2009/+ Theme Session Number Title of abstract Plankton features vs environmental quality in the inner zone of Bahía Blanca Estuary (Argentina) Name(s) of authors Hoffmeyer Mónica S., Barria de Cao María S., Berasategui Anabela, Pettigrosso Rosa, Dutto M. Sofía, López Abbate María C., Biancalana Florencia, Fulco Vanesa K., Fernández Severini Melisa, Menéndez M. Clara, Diodato Soledad, Barnech Bielsa, Guadalupe and Chazarreta Carlo J. The inner zone of Bahía Blanca Estuary is associated with an intense industrial, maritime activity and periodic dredging. A monthly biomonitoring has been carried out as of 2006 in order to determine a planktonic baseline in this area. Environmental data as well as information on the taxonomic composition, biomass, abundance and diversity of phyto, micro, meso- and macrozooplankton were recorded along seven stations of the Principal Channel in 2007. 53 phytoplanktonic taxa were found whereas of the microzooplankton 22 taxa were observed. 70 meso- macrozooplanktonic taxa were found. Crustaceans were the dominant fraction, the copepods Acartia tonsa (native) and Eurytemora americana (invader) being the dominant ones. Mesozooplankton showed highest mean abundance and biomass values in summer and ending winter. These values coincided with A. tonsa (6,232 ind m-3) and E. americana (18,543 ind m-3) population peaks, the latter being the highest than those recorded to date. Macrozooplankton was scarce and presented maximum abundance and biomass in summer which coincided with the mysidacean Arthromysis magellanica (212.24 ind m-3) population peak. Changes in the temporal and spatial distribution of phyto- and microzooplankton composition which lead to changes in the diversity values, were recorded with respect to data from 1996-1997.  In addition, variations in the temporal and spatial composition of micro-, meso- and macrozooplankton, a higher abundance and biomass, and differences in specific diversity were recorded in the present research with respect to those mentioned historic data. Keywords: biomonitoring, phytoplankton, micro-, meso-, macrozooplankton, turbid estuary, Acartia tonsa, Eurytemora americana, diversity.Contact author: Dr. Mónica S. Hoffmeyer, IADO, CCT-BB Bahía Blanca Argentina (CONICET). bmhoffme@criba.edu.ar.