Giuseppe Montanari

Toward Marine Environmental Predictions in the Mediterranean Sea Coastal Areas: A Monitoring Approach

Marine environmental predictions involve the observation and modeling of physical, biogeochemical processes and parameters, fused by advanced data assimilation schemes that optimally merge the observational and numerical modeling information in order to produce forecasts. The result of such system should be interfaced with socio-economic models of sustainable development and management of marine resources. Fusing the deterministic dynamical information about the marine ecosystem with the socio-economic and political knowledge of the marine environment has not been tried yet but it is one of the outstanding challenges in integrated coastal management studies. This paper tries to show a scientific strategy to predict the physical and biochemical components toward marine environmental predictions, being aware that some considerations could be changed in view of the integration with socio-economic models and issues. Here we use prediction in total analogy with forecasting and thus as synonymous of deterministic prognosis of dynamical variables from a pre-defined initial state of the system.

Bioaccumulation of algal toxins and changes in physiological parameters in Mediterranean mussels from the North Adriatic Sea (Italy)

The Northwestern Adriatic Sea is a commercially important area in aquaculture, accounting for about 90% of the Italian mussel production, and it was subjected to recurring cases of mussel farm closures due to toxic algae poisoning. A spatial and temporal survey of four sites along the North Adriatic Sea coasts of Emilia Romagna (Italy) was undertaken to study the possible impairments of physiological parameters in Mytilus galloprovincialis naturally exposed to algal toxins. The sites were selected as part of the monitoring network for the assessment of algal toxins bioaccumulation by the competent Authority. Samples positive to paralytic shellfish toxins and to lipophilic toxins were detected through the mouse bioassay. Lipophilic toxins were assessed by HPLC. Decreasing yessotoxins (YTX) levels were observed in mussels from June to December, while homo‐YTX contents increased concomitantly. Lysosome membrane stability (LMS), glutathione S‐transferase and catalase activities, and multixenobiotic resistance (MXR)‐related gene expressions were assessed as parameters related to the mussel health status and widely utilized in environmental biomonitoring. Levels of cAMP were also measured, as possibly involved in the algal toxin mechanisms of action. Low LMS values were observed in hemocytes from mussels positive to the mouse bioassay. MXR‐related gene expressions were greatly inhibited in mussels positive to the mouse bioassay. Clear correlations were established between increasing homo‐YTX contents (and decreasing YTX) and increasing cAMP levels in the tissues. Similarly, significant correlations were established between the increase of homo‐YTX and cAMP levels, and the expressions of three MXR‐related genes at submaximal toxin concentrations. In conclusion, YTXs may affect mussel physiological parameters, including hemocyte functionality, gene expression and cell signaling.

Responses of a Northern Adriatic Ampelisca–Corbula community to seasonality and short-term hydrological changes in the Po river

During the 20th century, increased nutrient inflow has increased the frequency and intensity of eutrophication events in the North-western Adriatic Sea. More recently, evidence of a reduction in the Po river flow and a recovery of the benthic environment were reported. We examined the role played by Po river regime and seasonality in determining the temporal pattern of macrozoobenthos variation: samples were collected from a site located 10-12km off Cesenatico during two years from October 2004 to September 2006, when the mean Po discharge remained exceptionally low. 88 taxa were found, and the community was dominated by few species: Ampelisca diadema, Lumbrineris latreillii, Corbula gibba, Aricidea claudiae, Levinsenia gracilis and Nucula nucleus account for about 80% of total abundances. The density of these species exhibited a marked seasonal variability. Moreover, the total abundance and the density of the sensitive species, A. diadema, were negatively affected by several disturbance events (hypoxic conditions, frequent storms and an anomalous winter flood) that occurred between November 2005 and March 2006. The reduction of C. gibba and the increase of A. diadema densities observed in the investigated period, and verified recently by other authors could be related to the reduction in river inputs as a consequence of climatic changes.

Eutrophication in the Emilia‐Romagna Coastal Waters in 1984–1985

Due to their geomorphic and hydrologic characteristics and because of the type and quantity of material carried down from inland regions, Emilia-Romagna’s coastal waters are subject to periodic and intense eutrophication. Over the last ten years this phenomenon has appeared in all of its by now well-known manifestations-abnormal water color, unpleasant smell, and, when the algae bloom in summer or autumn, a more or less extensive oxygen deficiency. This latter will depend on the extent of the bloom, the amount of the algae biomass, and the weather conditions (calm sea, water stratification, static hydrodynamic situation). As a general rule, eutrophication begins after rain. If such rains are heavy and widespread, they can increase the flow of the river Po and other coastal rivers, thus draining quantities of nutrients into the sea which can then set off and support algal bloom. If there are no high seas, the next phase involves a considerable increase in the concentration of the algal biomass. In fact, if we express this in terms of chlorophyll a , this can reach levels of 50-100 p g h . Under these circumstances, the water is cloudy and its color will take on a particular tone (red, brown, green, etc.) depending on the types of phytoplankton causing the bloom. Once the development stage is over, but especially once the supply of nutrients has been used up, the algae biomass dies and tends to deposit on the bottom where the mineralizing process carried out by bacteria requires very large amounts of oxygen dissolved in the water (FIG. 1). If this situation coincides with a calm sea, it can produce an oxygen deficiency that can be more or less extensive and cause the all too-well-known phenomenon of benthonic organism die-offs (bottom-feeding fish, molluscs, coelenterates, annelids, etc.) From the point of view of distribution, that is, the incidence of this phenomenon along the Emilia-Romagna coast, we can divide the entire section of this coast into three sub-areas (FIGS. 2 and 3). The first and most northerly includes the section between Goro and outer breakwaters of the port canal at Ravenna. This sector is most susceptible to eutrophication since it is not only directly affected by the water from the river Po (Po di Goro and Po della Gnocca-25 percent of the entire flow rate of the river), but it also receives water from the Burana-Volano, the Ferrarese Idrovia, from the Valli di Comacchio through tidal effect, and from the Reno, the Destra Reno and the Lamone rivers. Apart from the question of the nutrient input during the summer-autumn pe-

Mucilaginous masses in the Adriatic sea in the summer of 1989

Abstract This paper reports on one of the most recent episodes of mucilage formation in the central–northern part of the Adriatic coast in July–August 1989. The stretch of coast examined goes from the estuary of the River Po to the border of the Marche–Abruzzo coast (Italy). The possible events (nutrients, N/P ratio, particular climatic conditions) that cause the formation of the mucilage masses were examined and are discussed here. Furthermore, the oxygenation state of the water on the surface and on the bottom as well as the possible effects on molluscs were also examined. The field results indicated that no anoxia phenomena were found in bottom waters caused by mucilages, and that mollusc death was probably due to mechanical reasons. Finally the places where the mucillages formed and their subsequent movements are described.