Animal-sediment relationships: evaluating the 'Pearson-Rosenberg paradigm' in Mediterranean coastal lagoons.

We investigated the applicability of the Pearson-Rosenberg (P-R) conceptual model describing a generalized pattern of response of benthic communities in relation to organic enrichment to Mediterranean Sea coastal lagoons. Consistent with P-R model predictions, benthic diversity and abundance showed two different peaks at low (>2.5-5 mg g(-1)) and high (>25-30 mg g(-1)) total organic carbon (TOC) ranges, respectively. We identified TOC thresholds indicating that risks of reduced benthic diversity should be relatively low at TOC valuesabout 28 mg g(-1), and intermediate at values in-between. Predictive ability within these ranges was high based on results of re-sampling simulation. While not a direct measure of causality, it is anticipated that these TOC thresholds should serve as a general screening-level indicator for evaluating the likelihood of reduced sediment quality and associated bioeffects in such eutrophic systems of the Mediterranean Sea.

Seasonal variations of selected herbicides and related metabolites in water, sediment, seaweed and clams in the Sacca di Goro coastal lagoon (Northern Adriatic).

This study assesses the status of Sacca di Goro coastal lagoon (Northern Adriatic, Italy) with respect to watershed pollution. Because 80% of its watershed is devoted to agriculture, plant protection products and their metabolites were found in the water column, sediments (the upper 0-15 cm layer), macroalgae (Ulva rigida) and clams (Tapes philippinarum). Five seasonal sampling campaigns were performed from May 2004 to April 2005 and concentrations measured in five stations in the lagoon and six in the watershed. Relatively high concentrations of the s-triazine - terbuthylazine -, urea herbicides - diuron - and alachlor were detected through the year mainly at stations directly influenced by the Po di Volano inflow. The concentrations of products in use follow a clear seasonal pattern with spring peaks. This pattern is also visible in the sediments as well as in biota. Among metabolites, hydroxylated compounds prevailed, often with concentrations greater than those of the parent compounds. For the most part of the year, the concentrations in biota were close to detection limits, with concentration peaks in spring.

A 3D hydrodynamic fate and transport model for herbicides in Sacca di Goro coastal lagoon (Northern Adriatic).

Sacca di Goro is a shallow coastal microtidal lagoon with a surface area of 26 km2, and an average depth of about 1.5m. Fresh water pollutant loads from Po River branches and several drainage canals lead to anthropogenic eutrophication, frequent summer anoxia crises and chemical contamination. Such events not only affect the lagoon ecosystem but also cause serious economic losses, the lagoon being the second largest producer of clams in Italy. The present work aims at using a fate model coupled with COHERENS 3D hydrodynamic model to simulate and to explain the spatial distribution and temporal variations of s-triazines herbicides in the Sacca di Goro lagoon. The simulation results of spatial and temporal dynamic behaviour of atrazine, simazine and terbuthylazine have been compared with experimental data obtained during an annual monitoring programme.

On-line purge-and-trap-gas chromatography with flame ionization detection as an alternative analytical method for dimethyl sulphide trace release from marine algae.

The release of dimethyl sulphide (DMS) by the seaweed Ulva spp at trace level was studied in aqueous solutions at different salinities, temperature and light intensities. For this purpose, the purge-and-trap technique combined with gas chromatography-flame ionization detection was used. The analytical method was evaluated in terms of linearity range, limit of detection, precision and accuracy by considering 10@1000 (w/v) and 30@1000 (w/v) synthetic seawater as aqueous matrices. Calculation of the recovery function evidenced a matrix influence. The method of standard addition was then used for an accurate determination of DMS in synthetic seawater reproducing the matrix effect. DMS fluxes were analysed in batch cultures of Ulva spp reproducing the conditions which usually occur in the Sacca di Goro lagoon (Northern Adriatic Sea, Italy).

A Multimethodological Approach for the Sustainable Management of Perifluvial Wetlands of the Po River (Italy).

/ Marginal aquatic systems (wetlands) of the Po River (Italy) have become the target of a renewed interest because of their value for recreation, natural reserves, and deposits of sand. To preserve these sites, wise management must be the objective of local administrations. In this paper a strategy for the sustainable use of 11 wetlands is presented. It uses simple economic analysis and multiple criteria techniques and provides suggestions to promote sustainability in terms of conservation of natural resources, economic self-sufficiency, and minimization of potential conflicts about the use of the wetlands. In the understanding that sustainability is framed in a long-term perspective, stability analysis is also considered and performed by means of loop analysis, a qualitative technique. Conditions for stability are then discussed about management opportunities.