Search results for " ECOLOGIA"

HCB, p,p'-DDE and PCB ontogenetic transfer and magnification in bluefin tuna (Thunnus thynnus) from the Mediterranean Sea.

2007

The bluefin tuna, Thunnus thynnus (Linnaeus 1758), is biologically and economically important in the Atlantic--Mediterranean ecosystems. Bluefin tuna feed on diverse food items depending on their age, thus they occupy different trophic levels during their lifespan. Hexachlorobenzene (HCB), p,p'-DDE and polychlorinated biphenyls (PCBs) are well-known persistent organic pollutants (POPs) in the Mediterranean basin. The relationship between stable isotopes of nitrogen (N) and the POP residue levels in tissues has recently increased knowledge on the link between the trophic levels and the contaminant accumulation. Trophic levels were estimated by using 15N/14N ratio (delta15N) and HCB, p,p'-DDE…

Trace elements and stable isotopes in penguin chicks and eggs: A baseline for monitoring the Ross Sea MPA and trophic transfer studies.

2021

Multi-tissue trace elements (TEs), C, N concentrations and stable isotopes (δ13C, δ15N) of chick carcasses and eggs of Adelie and Emperor penguins were studied to i) provide reference data before the recent institution of the Ross Sea Marine Protected Area (Antarctica), and ii) provide conversion factors that allow estimating C, N, δ13C and δ15N in edible tissues from non-edible ones, thus improving the use of stable isotopes in contamination and trophic transfer studies. Higher concentrations of As, Cd, Cr, Cu, Hg, Mn and Pb were found in chick carcasses than in eggs, suggesting increasing contamination in recent decades and high toxicity risks for penguin consumers. Isotopic conversion fa…

Formulation of a new sustainable feed from food industry discards for rearing the purple sea urchin Paracentrotus lividus

2020

The lack of suitable feeds for echinoculture has led to use natural resources already widely exploited by human activities. To move towards a higher sustainability of echinoculture, this study proposes a sustainable feed for Paracentrotus lividus. Two experimental formulations were obtained using discarded endive (Cichorium endivia) leaves and anchovy (Engraulis encrasicolus) industry discards in different proportions, and agar as a binder. The evaluation of the feed stability showed that the feed was stable for 72 hr, allowing a suitable feeding for sea urchins. Both formulations showed a proper nutritional value and fatty acid profile, corresponding to the features of the main ingredients…

Effects of fish-farm biodeposition on periphyton assemblages on artificial substrates in the southern Tyrrhenian Sea (Gulf of Castellammare, Sicily)

2007

An algal assemblage growing on artificial substrata of fish-farm cages was investigated. Specifically, algal response to the effects of fish-farm facilities was studied, in order to identify a possible future descriptor of biodeposition impact. Some sites were positioned upstream of the farms (at least 750 m; ‘controls’) and other sites were positioned downstream of the farms (‘impacts’). All sites were situated in the Tyrrhenian Sea. Control and impact sites differed significantly with regard to the dissolved nutrient profile. The fouling community (samples were scraped from buoys) displayed a reduction gradient in diversity which increased with the effect of fish farms. A total of 51 taxa…

Composizione e struttura della comunità di fouling in un impianto di maricoltura (Golfo di Castellammare, Sicily N-O)

2005

Short-term exposure to concurrent biotic and abiotic stressors may impair farmed molluscs performance

2022

Global warming, through increasing temperatures, may facilitate the spread and proliferation of outbreak-forming species which may find favourable substrate conditions on artificial aquaculture structures. The presence of stinging organisms (cnidarian hydroids) in the facilities fouling community are a source of pollution that can cause critical problems when in-situ underwater cleaning processes are performed. Multiple stressor experiments were carried out to investigate the cumulative effect on farmed mussels' functional traits when exposed to realistic stressful conditions, including presence of harmful cnidarian cells and environmental conditions of increasing temperature and short-term…

Functional traits, mechanistic bioenergetics and microclimatic downscaling of marine ectotherms

2014

Genetic structure in the Mediterranean seagrass Posidonia oceanica: disentangling past vicariance events from contemporary patterns of gene flow

2010

The Mediterranean Sea is a two-basin system, with the boundary zone restricted to the Strait of Sicily and the narrow Strait of Messina. Two main population groups are recognized in the Mediterranean endemic seagrass Posidonia oceanica, corresponding to the Western and the Eastern basins. To address the nature of the East-West cleavage in P. oceanica, the main aims of this study were: (i) to define the genetic structure within the potential contact zone (i.e. the Strait of Sicily) and clarify the extent of gene flow between the two population groups, and (ii) to investigate the role of present water circulation patterns vs. past evolutionary events on the observed genetic pattern. To achiev…

Biochemical genetic differentiation between Pomatoschistus marmoratus and P. tortonesei

1999

Several diagnostic genetic markers were identified in Pomatoschistus marmoratus and P. tortonesei using polyacrylamide gel electrophoresis (PAGE) of allozymes. Twenty-one loci were resolved, including the electrophoretic pattern of muscle proteins. The MDH*, PGM1,2*, EST-1,2*, FUM* and PGI-2* loci exhibited different alleles which were fixed for the two species being analysed. Genetic distance, as calculated by Nei's index, showed a value of 0.413. Environmental hypersalinity, could have influenced the geographical distribution of P. tortonesei.

Valuing the unmarketable: an ecological approach to the externalities estimate in fishing activities

2013

In a rapidly changing world, sustainability, if it can be said to exist at all, is concept that has attained mythic status, often pursued and rarely reached. In order to improve our capability to cope with environmental problems, adopting an Ecosystem Approach has been suggested. One of the major challenges in the implementation of this new paradigm relates to control of externalities. The recognition and quantification of externalities is often cast as valuing the unmarketable, and there are several approaches that have been proposed. Here, we analyze the opportunity to “feed” the economic valuation with ecological concepts. From an ecological perspective, the energy required to sustain a …