The composition and the secondary production of a benthic macroinvertebrate community in a brackish lake located in the southernmost area of the Po River Delta was investigated. Three stations (N, C., and S) were selected and sampled quarterly for macrofauna and environmental parameters. Data were subjected to multivariate statistical analysis to discriminate between season-ality and sites on their faunistic attributes, and univariate measures of community stress were determined. Water parameter values were typical of eutrophic areas. A total of 23 species belonging to four phyla were identified. Macrobenthic faunal assemblages of the lake were dominated by deposit-feeders. At the three sampling sites, polychaetes were the most abundant taxon, accounting respectively for 65.3%, 87.9% and 51.6% of the total number of individuals. Substratum characteristics, together with fluctuations in environmental parameters, played an important role in structuring faunistic assemblages. In terms of biomass, molluscs made the greatest contribution at stations N and S, representing, respectively, 56.3% and 55.2% of total biomass, while polychaetes contributed mostly to station C with 73.6%. Mean annual production of the macrobenthic community of the lake was estimated as 5.2 g AFDW 0.06 m-2 yr-1, with a production/biomass ratio (P/B) of 2.1. © 1999 Taylor & Francis Group, LLC.
Structure and production of the benthic macroinvertebrate community in a shallow lagoon of the Po River Delta
MISTRI, Michele;ROSSI, Remigio
1999
Abstract
The composition and the secondary production of a benthic macroinvertebrate community in a brackish lake located in the southernmost area of the Po River Delta was investigated. Three stations (N, C., and S) were selected and sampled quarterly for macrofauna and environmental parameters. Data were subjected to multivariate statistical analysis to discriminate between season-ality and sites on their faunistic attributes, and univariate measures of community stress were determined. Water parameter values were typical of eutrophic areas. A total of 23 species belonging to four phyla were identified. Macrobenthic faunal assemblages of the lake were dominated by deposit-feeders. At the three sampling sites, polychaetes were the most abundant taxon, accounting respectively for 65.3%, 87.9% and 51.6% of the total number of individuals. Substratum characteristics, together with fluctuations in environmental parameters, played an important role in structuring faunistic assemblages. In terms of biomass, molluscs made the greatest contribution at stations N and S, representing, respectively, 56.3% and 55.2% of total biomass, while polychaetes contributed mostly to station C with 73.6%. Mean annual production of the macrobenthic community of the lake was estimated as 5.2 g AFDW 0.06 m-2 yr-1, with a production/biomass ratio (P/B) of 2.1. © 1999 Taylor & Francis Group, LLC.I documenti in SFERA sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
