A phytoplankton study of Southern Adriatic waters near Dubrovnik for the period from June 1979 to July 1980

Abstract

The spatial and temporal dynamics of populations, as well as the biomass expressed as the total cell volume of particular size and taxonomical categories of phytoplankton in the southern Adriatic near Dubrovnik were investigated. All analyses were based on 100 plankton net samples and 310 Nansen bottle samples taken at 9 stations. The phytoplankton parameters, such as distribution of species, distribution of phytoplankton cell density and biomass, as well as species diversity were used for the ecological characterization of the investigated area. A total of 284 microplankton taxons were determined. The microplankton quantity ranged from 2.2 x 102 to 4.0 X 106 cells/ I, and 9.2 x 105 to 7.6 X 109 j.Lm3/1 respectively. The nanoplankton ,;ell density ranged between 6.2 x 104 and5.2 x 106 cells/I, and cell volume between 3.9x 106 and 9.1 x 108 j.Lm3 /1. The most frequent values of the Shannon and Weaver diversity index ranged between 3 and 4 at open sea stations and between 2 and 3 at coastal stations.