Evidence for trophic structure variability in Mediterranean coastal lagoons.

Analysis of the trophic role of primary producers in Posidonia oceanica ecosystems along the Sicilian coasts (Italy)

Il Laboratorio di Biologia Marina e Risorse

Analysis of the trophic structure in zones with different levels of protection within the Marine Protected Area “Isola di Ustica” based on carbon and nitrogen stable isotopes

Analysis of stable carbon and nitrogen isotopes as a tool for assessing the environmental impact of aquaculture: a case study from the western Mediterranean

Stable carbon and nitrogen isotope ratios ( 13C/ 12 C and 15N/14 N) of in situ dominant primary producers and consumers were investigated to assess the impact on a natural ecosystem of a land-based fish farm along the south-western coast of Sicily (Italy). The putatively impacted area close to the farm along outfall was compared with other locations at increasing distances from the outfall. Carbon and mainly nitrogen stable isotopes revealed evidence of widespread aquaculture waste in the study site: benthic organisms collected in the impacted area showed more enriched δ 15N signatures than those at greater distances from the outfall, suggesting a large contribution of aquaculture waste to …

A study of the pattern of digestive enzimes in Diplodus puntazzo (Cetti, 1777) (Osteychthyes, Sparidae): evidence for the definition of nutritional protocols

The digestive enzymes (proteases, carbohydrases and lipases) present along the alimentary tract of juveniles and adults of Diplodus puntazzo were studied. The data obtained showed a different distribution of the enzymatic activities in the different parts of the alimentary tract. Levels of enzymatic activity in the adults were higher than those measured in juveniles, suggesting that adults have a greater ability to digest larger pieces of food. The enzymatic pattern of D. puntazzo justifies its omnivorous habit and suggests an high potential for digesting vegetable polysaccharides. The results of this study suggest the need to adapt the diet to the digestive potential of this new farming sp…

Impact on the water column biogeochemistry of a Mediterranean mussel and fish farm

We investigated and compared the impact of organic loads due to the biodeposition of mussel and fish farms on the water column of a coastal area of the Tyrrhenian Sea (Western Mediterranean). Physico-chemical data (including oxygen, nutrients, DOC and particulate organic matter), microbial variables (picoplankton and picophytoplankton density and biomass) and phytoplankton biomass (as chlorophyll-a) were determined on a monthly basis from March 1997 to February 1998. The results of this study indicate that both fish farm and mussel culture did not alter significantly dissolved inorganic phosphorus and chlorophyll-a values, while inorganic nitrogen concentrations were higher in mussel farm a…

Spatial variability of stable carbon and nitrogen isotope ratios in a Mediterranean coastal lagoon

Exploring the trophic pathway of organic matter within the Mauguio lagoon (southern France, western Mediterranean), we found spatial differences in the isotopic composition (both δ13C and δ15N values) of organic matter sources (primary producers, particulate and sedimentary organic matter), which were mirrored in the upper trophic levels (invertebrates and fish). On average, δ13C was heavier by about 1.5–2‰ in the location under marine influence than in the sites influenced by freshwater discharge. The opposite trend was found for δ15N, which attained maximum values in the north-central zone influenced by freshwater delivery. For both C and N stable isotope ratios, the highest spatial varia…

Digestive Enzymes in Larvae and Juveniles of Farmed Sharpsnout Seabream (Diplodus puntazzo) (Cetti, 1777)

The ontogenetic development and pattern of main digestive enzyme activities (proteases, carbohydrases and lipases) were investigated in farmed sharpsnout seabream Diplodus puntazzo larvae and juveniles, during the passage from the larval stage to adult (from 21 to 277 days after hatching - DAH). Larvae showed exponential growth, thus confirming that Rotifers and Artemia nauplii are suitable preys for early feeding of D. puntazzo larvae. Pepsin activity was low in the larvae, but it increased afterwards in relation with stomach development. In juveniles, levels of specific activity of trypsin, chymotrypsin and elastase were lower compared to that recorded in larvae. A decrease in the activit…

Studio degli isotopi stabili di carbonio ed azoto e dei metalli pesanti in diverse specie di Mugilidi provenienti da aree lagunari mediterranee

Approccio isotopico per lo studio dell’impatto di attività di acquacoltura in ambiente marino costiero

Valutazione dei livelli di alcuni metalli pesanti in una catena del detrito ricostruita attraverso l’analisi degli isotopi stabili di carbonio ed azoto

The fate of terrestrial and riverine materials in a Mediterranean seagrass bed

The origin and fate of organic matter as a tool to assess anthropogenic disturbance in coastal environments

Studio dell’impatto di un’attività di maricoltura attraverso l’analisi della Materia Organica Sedimentaria

Nitrogen stable isotopes as tracers of biodeposition from a tuna farm in the Western Mediterranean

Studio dell’impatto di un’attività di acquicoltura sui sedimenti della costa sud-occidentale della Sicilia attraverso l’analisi della composizione biochimica della materia organica sedimentaria

Spatial variability in stable carbon and nitrogen isotope ratios in a Mediterranean coastal lagoon (Mauguio, France).

Struttura e distribuzione della comunità macrozoobentonica dello Stagnone di Marsala (Sicilia Nord-Occidentale)

Effetti ambientali della stabulazione del tonno rosso (Thunnus thynnu, L. 1758): analisi del materiale sedimentato

Densità e composizione isotopica di Dendropoma petraeum (Caenogastropoda, Monterosato, 1884): confronto tra le diverse porzioni della piattaforma a vermeti

Ichthyofauna Trophic structure from three adjacent Mediterranean lagoons.

Definizione dello stato trofico nelle Saline del trapanese attraverso lo studio della materia organica sedimentaria e particellata

Effects of aquaculture activities on seagrass ecosystems: evidence from stable isotopes

Evidence for the cascade effect in the Marine Protected Area “Isola di Ustica”

Evidence for trophic structure varibility in Mediterranean coastal lagoons

Effetti ambientali della stabulazione del tonno rosso (Thunnus thynnus L.): analisi della materia organica sedimentaria

Heavy metals and stable isotope ratios in organisms from three adjacent Mediterranean coastal lagoons

Assessing the environmental impact of aquaculture: a new approach based on stable isotope analysis