Preliminary Analysis on Correlations between Spatial Distribution of Chlorophyll-a and Experimental Data of Biomass in the Strait of Sicily

This study, using both remotely sensed and measured in situ data, is directed to the analysis of the correlations between the chlorophyll-a concentration and the biomass of sardines and anchovies acoustically evaluated in the Strait of Sicily. This work, inter alia, shows the usefulness of remote observation of seas in determining possible relationships between fish stocks and some oceanographic parameters (Sea Surface Temperature, Chlorophyll-a, Zooplankton).

Use of Hydroacoustic Methods for the Identification of Potential Seabed Habitats for Small Pelagic Fish Schools in the Strait of Sicily

Study of benthic foraminifera in the Continental Shelf of the Gulf of Gela (Sicilian Channel) and their possible use as bioindicators

Heavy metals analysis by non invasive techniques for fish food quality control

Studio delle tanatocenosi a foraminiferi bentonici nel Golfo di Gela

THE EFFECT OF HEAVY METALS ON BENTHIC FORAMINIFERA IN THE GULF OF GELA (SICILIAN CHANNEL)

Benthic foraminifera are very sensitive to oceanographic parameter variations, to which they rapidly response through changes in the abundance and/or richness of their associations and in morphological variations of their shell. Many studies have used benthic foraminifera as bioindicators. We investigated recent benthic foraminiferal assemblages in the Gulf of Gela (Sicilian Channel, Mediterranean Sea), examining their relative abundance, specific richness and morphological abnormalities, to highlight a possible correlation with oceanographic features and the concentration of heavy metals in sediments. Sediment was sampled in summer 2006 using box corers in four stations at increasing dista…

Lo stato dell’ambiente marino nell’area del Canale di Sicilia in prossimità del SIN di Gela.

Viene illustrata in questa nota l’attuale condizione in cui si trova lo stato dell’ambiente marino nell’area del Canale di Sicilia immediatamente a ridosso della costa merdionale delle Sicilia dal Golfo di Gela alla costa iblea. Lo stato dell’ambiente in oggetto viene valutato in base alla distribuzione di alcuni metalli in tracce normalmente ritenuti fra i più significativi per gli scopi prefissati, esaminati lungo la colonna d’acqua e nei sedimenti superficiali di fondale. I risultati ottenuti, illustrati anche attraverso un’indagine statistica multivariata, indicano un arricchimento superficiale della colonna d’acqua in lantanio che può essere ascritto tanto ad un’origine litogenica, qua…

Linking air–sea energy fluxes and European anchovy potential spawning ground.

The physical and chemical processes of the sea greatly affect the reproductive biology of fishes, mainly influencing both the numbers of spawned eggs and the survivorship of early stages up to the recruitment period. In the central Mediterranean, the European anchovy constitutes one of the most important fishery resource. Because of its short living nature and of its recruitment variability, associated to high environmental variability, this small pelagic species undergo high interannual fluctuation in the biomass levels. Despite several efforts were addressed to characterize fishes spawning habitat from the oceanographic point of view, very few studies analyze the air-sea exchanges effects…

Two-species model for spatial distributions of sardine and anchovy: A comparison with real data

We present a study of pattern formation in a set of two coupled equations modeling two competing species. We consider generalized Lotka-Volterra equations in the presence of a multiplicative noise which models the interaction between the species and the environment. The interaction parameter between the species is a random process which obeys a stochastic differential equation with a generalized bistable potential in the presence of a periodic driving term, which accounts for the environment temperature variation.We find noise-induced spatial patterns with strong anti-correlation between the two species. We compare our theoretical results with the experimental data of the spatial distributi…

A stochastic reaction-diffusion-taxis model for two picophytoplankton populations

In this work, the stationary distributions of two populations of picophytoplankton, i.e. picoeukaryotes and Prochlorococcus, are studied. This two groups account on average for 60% of the total chlorophyll a (chl a) and divinil chlorophyll a (divinil chl a) concentration in Mediterranean Sea. The interaction of these populations with the environment occurs through two factors that limit the growth of the aquatic microorganisms: light intensity and nutrient, i.e. phosphorus. The dynamics of the two picophytoplanktonic groups, distributed at different depth along a water column (one-dimensional spatial domain), is analyzed starting from a deterministic reaction-diffusion-taxis model. This con…