ZOOPLANKTON VARIABILITY RELATED TO ENVIRONMENTAL-CHANGES IN A EUTROPHIC COASTAL LAGOON IN THE PO DELTA

Citation
S. Sei et al., ZOOPLANKTON VARIABILITY RELATED TO ENVIRONMENTAL-CHANGES IN A EUTROPHIC COASTAL LAGOON IN THE PO DELTA, Hydrobiologia, 329(1-3), 1996, pp. 45-55
Citations number
23
Categorie Soggetti
Marine & Freshwater Biology
Journal title
ISSN journal
00188158
Volume
329
Issue
1-3
Year of publication
1996
Pages
45 - 55
Database
ISI
SICI code
0018-8158(1996)329:1-3<45:ZVRTEI>2.0.ZU;2-1
Abstract
Zooplankton variability in a lagoon of the Po Delta, the Sacca di Gore , was studied in relation to changes in its hydrodynamic and hydrologi cal features. From 1987 to 1992 the lagoon was affected each summer by severe anoxia due to the decomposition of dense and widespread beds o f Ulva rigida. In August 1992 a canal was opened through the sand bank closing off the lagoon from the sea in order to improve the water cir culation. This hydraulic intervention led to significant environmental changes in the lagoon: during the two subsequent years the summer dys trophic crises were brief and less severe, due to a sharp decrease in the Ulva cover. At the same time a clear increase in phytoplankton bio mass values was observed. Following the opening of the channel, the mo st remarkable change in zooplankton was a significant density increase of calanoids, particularly of Acartia tonsa.