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Environmental conditions in a lagoon and their possible effects on shellfish contamination by Giardia andCryptosporidium
No full textLe acque interne del Parco Nazionale del Gargano: un biotopo da conservare e gestire in modo ecosostenibile
No full textComparative study based on sediment characteristics and macrobenthic communities in two italian coastal lagoon
No full textThe aims of this study were to analyse sediment characteristics and macrobenthic assemblages in two very close Italian coastal lagoons (Lesina and Varano) and to assess the different behaviour between the two basins and the relationship between sediment matrix and benthic organisms within and between the two lagoons. The comparative study was performed in July 2007 at 13 sampling sites in Lesina lagoon and 15 sites in Varano basin for sediment grain size, total organic carbon (TOC), total nitrogen (TN), total phosphorus (TP) and macrobenthic structure analyses. Both lagoons were generally dominated by fine-grained sediments (clay and silt components). The average contents of TOC and TN measured in Lesina was higher than in Varano (3.31% vs 2.52% for TOC and 5,200 μg•g-1 vs 3,713 μg•g-1 for TN); in contrast, the TP was lower (540 μg•g-1 vs 620 μg•g-1). Based on macrobenthic community patterns, the central zone in Varano lagoon and the eastern area in Lesina lagoon were characterised by the lowest abundance (168.7 ind•m-2 and 503.2 ind•m-2, respectively) and by the lowest number of species, as highlighted by the diversity indices (Shannon-Wiener, H ′ range was 0.47-1.45 for Lesina and 0.00-1.68 for Varano; Margalef species richness, d range was 0.00-1.67 for Lesina lagoon and 0.00-2.38 for Varano basin). Ordination diagrams suggested an influence of marine and freshwater inputs on the sediment distribution in Varano lagoon and on macrobenthic assemblages in Lesina lagoon. © 2008 Springer Science+Business Media B.V
Complessità ecologica e variabilità funzionale della Laguna di Lesina: interazione tra comparto microbico bentonico e materia organica sedimentaria
No full textMetapopulation structure in the mollusc bivalve Loripes lacteus in Varano lagoon (SE Italy)
No full textPopulation structure and spatial distribution of Loripes lacteus (Linnaeus, 1758) in Varano lagoon, SE Italy
No full textIn Varano lagoon (Puglia, Italy) the bivalve Loripes lacteus (Linnaeus, 1758) constitutes the most
abundant species among the organisms of the benthic macrofauna. This work presents the results
of five years (from 2001 at 2006) of observations on the abundance, size/age population structure
and spatial distribution of this species within the basin (6500 ha). L. lacteus is one of the most
common and frequent bivalve species in Mediterranean lagoons. It typically occurs in reduced
sediments where it is able to live at low oxygen concentration due to a particular respiratory pigment
haemoglobin. Lucinid bivalves house symbiotic, sulphur-oxydizing chemoautotrophic bacterias in
their gills, which contribute substantially to their nutrition.
2 - The design was to perform two sampling campaignes on yearly basis during the intermediate seasons
(Spring and Autumn), when possible. Each sampling was realized collecting 53 sampling units taken
from 53 stations distributed regularly over the lagoon surface. Each sampling unit consisted in all
the individuals contained in a solid 15 x 15 x 20 cm of sediment and held on 1 mm mesh.
3 - Growth patterns were determined with the Bhattacharya method which uses modal progression
analysis from size frequency distribution.
4 - The results showed a spatial distribution of L. lacteus which occurred in patches and changed among
samples. The population analysis showed two modal classes for each sampling time.
5 - L. lacteus is an “r” strategy species with small size, brief life cycle, with great capacity of recovery
after environmental crises
Bioaccumulation in European eels (Anguilla anguilla L.) of pollutants from human origin: a comparison between two Italian lagoons characterized by different human pressures (Varano and Orbetello)
No full textEnvironmental heterogeneity patterns and assessment of trophic levels in two Mediterranean lagoons: Orbetello and Varano, Italy
No full textEnvironmental heterogeneity patterns and assessment of trophic levels in two Mediterranean lagoons: Orbetello and Varano, Italy
No full textThe management of coastal lagoons is of particular interest due to their high economical importance. In spite of their great productivity, coastal lagoons are often impacted by human pressure which produces water eutrophication. The aim of this paper is to assess the trophic state of the two Mediterranean lagoons taking into account chemical-physical parameters, nutrient concentrations and biological parameters. Two Italian lagoons, Orbetello and Varano (respectively located in Tyrrhenian and Adriatic coast, Italy) were studied between May 2003 and April 2005. Both these systems receive treated urban outflows, agricultural effluents and rivers freshwater inputs. Field collected data showed that studied lagoons were characterized by different human and natural pressures. Orbetello showed the highest water eutrophication, highlighted by the trophic index values, while Varano showed lower eutrophication levels except for the summertime. The values of physical, chemical and biological parameters measured in Orbetello and Varano lagoons indicate that a wide spatial and seasonal gradient of the water characteristics was established during the study period, but in particular in winter. This gradient, typical of estuarine systems, was essentially due to the mixing of freshwater, seawater and anthropogenic inputs. Orbetello lagoon seemed much more affected by the urban impact and the fish-farming activities than Varano lagoon, but the latter showed a greater agriculture activities impact as showed by the remote sensing images. © 2008 Elsevier B.V. All rights reserved
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