Our work was aimed to study the phytoplankton communities in two coastal sites placed in Natural Reserve “Lake of Tarsia-Mouth of river Crati” in Northern Ionian Sea-Calabria (Italy). This zone represents a wetland ...Our work was aimed to study the phytoplankton communities in two coastal sites placed in Natural Reserve “Lake of Tarsia-Mouth of river Crati” in Northern Ionian Sea-Calabria (Italy). This zone represents a wetland area of high natural interest populated by different organisms (animals and plants) living in a transitional ecosystem characterized by a great biodiversity. The sampling was performed in two different seasonal periods (summer and autumn 2012) and in two different sites (marine site vs fluvial one). Different algal genera/species were recognized and analyzed by Utermohl inverted microscope method and also qualitative and quantitative measures of biomass were performed. The results showed that the dominant group was the Diatoms with exclusive species in such periods in both the sampling sites;we also observed the presence of genera and/or species of potentially toxic algae (Pseudo-nitzschia sp., Alexandrium taylori, Prorocentrum micans, Skeletonema sp.), mostly in summer. Complessively, the phytoplankton biomass was always higher in marine site than in the fluvial site. The results were also processed considering the context of the chemical-physical parameters (such as temperature, pH, salinity, nutrients). The high concentration of the nutrients N and P in such periods indicated a state of meso-eutrophic waters both in the proximity of river site as well as in the marine zone. The data represent the first contribution to the knowledge of the phytoplankton structure in this area, which results in a very variable environment with a high recovery capacity.展开更多
As, Cd, Cu and Pb concentrations were measured in Posidonia oceanica sampled from meadows located in two sites along the calabrian coast (Ionian Sea, South-eastern Mediterranean). By dating the scales and the rhizome ...As, Cd, Cu and Pb concentrations were measured in Posidonia oceanica sampled from meadows located in two sites along the calabrian coast (Ionian Sea, South-eastern Mediterranean). By dating the scales and the rhizome using retrospective procedures (lepidochronology), a time series over a period of nine years (1995-2004) was analysed. Throughout the whole lepidochronological period, the arsenic content in the scales was tenfold higher than that measured in the rhizome with a peak in the lepidochronological year 1996-1997 and a general decrease in the years after. Pb concentration also showed a tendency to decrease with time, whereas the Cd and Cu concentration were increasing. A comparison of the metal level in dead sheaths (scales) and living tissue (leaves) was also performed. The detailed distribution of the trace metals along the leaf axis and in the leaves at different developmental stages (adult, intermediate and juvenile) showed some differences in the metal content. The results also indicate that the arsenic content measured in the leaf blade reflects the high As content measured at the superficial sediments at one of the two sampled sites, demonstrating, for the first time, that P. oceanica would be a good indicator for this element.展开更多
文摘Our work was aimed to study the phytoplankton communities in two coastal sites placed in Natural Reserve “Lake of Tarsia-Mouth of river Crati” in Northern Ionian Sea-Calabria (Italy). This zone represents a wetland area of high natural interest populated by different organisms (animals and plants) living in a transitional ecosystem characterized by a great biodiversity. The sampling was performed in two different seasonal periods (summer and autumn 2012) and in two different sites (marine site vs fluvial one). Different algal genera/species were recognized and analyzed by Utermohl inverted microscope method and also qualitative and quantitative measures of biomass were performed. The results showed that the dominant group was the Diatoms with exclusive species in such periods in both the sampling sites;we also observed the presence of genera and/or species of potentially toxic algae (Pseudo-nitzschia sp., Alexandrium taylori, Prorocentrum micans, Skeletonema sp.), mostly in summer. Complessively, the phytoplankton biomass was always higher in marine site than in the fluvial site. The results were also processed considering the context of the chemical-physical parameters (such as temperature, pH, salinity, nutrients). The high concentration of the nutrients N and P in such periods indicated a state of meso-eutrophic waters both in the proximity of river site as well as in the marine zone. The data represent the first contribution to the knowledge of the phytoplankton structure in this area, which results in a very variable environment with a high recovery capacity.
文摘As, Cd, Cu and Pb concentrations were measured in Posidonia oceanica sampled from meadows located in two sites along the calabrian coast (Ionian Sea, South-eastern Mediterranean). By dating the scales and the rhizome using retrospective procedures (lepidochronology), a time series over a period of nine years (1995-2004) was analysed. Throughout the whole lepidochronological period, the arsenic content in the scales was tenfold higher than that measured in the rhizome with a peak in the lepidochronological year 1996-1997 and a general decrease in the years after. Pb concentration also showed a tendency to decrease with time, whereas the Cd and Cu concentration were increasing. A comparison of the metal level in dead sheaths (scales) and living tissue (leaves) was also performed. The detailed distribution of the trace metals along the leaf axis and in the leaves at different developmental stages (adult, intermediate and juvenile) showed some differences in the metal content. The results also indicate that the arsenic content measured in the leaf blade reflects the high As content measured at the superficial sediments at one of the two sampled sites, demonstrating, for the first time, that P. oceanica would be a good indicator for this element.
