563 research outputs found
Impact of the feeding habits of the Great Cormorant Phalacrocorax carbo sinensis on the lagoon fish stocks in central western Sardinia
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Characterization of the Lipid Fraction of Wild Sea Urchin from the Sardinian Sea (Western Mediterranean)
No full textThe fatty acid (FA) composition of Spatangus purpureus, Echinus melo, Sphaerechinus granularis, and Paracentrotus lividus, sea urchins, has been studied. Sea urchins were collected at different depth along Sardinia coast in theMediterranean
sea, and their gonad was measured, separated, and analyzed for FA composition by gas chromatography-mass spectrometry.
A total of 53 FAs were detected, 16 saturated (SFA), 10 monounsaturated (MUFA), 9 polyunsaturated (PUFA), and 13
highly unsaturated (HUFA). Moreover, 5 furan FAs (FFAs) were revealed for the first time in sea urchin. The HUFA and
PUFA classes were the most represented accounting for almost 80% of total FAs. Among these compounds, C20:4 n6
(19.64, 20.52, 23.37, and 8.48 mg/g, respectively) and C22:6 n3 (19.68, 20.05, 3.83, and 1.78 mg/g, respectively) were
the most abundant. The results of principal component analysis indicated that the sea urchin samples could be clearly
discriminated with respect to their FAs composition
The effect of Mistral (a strong NW wind) episodes on the occurrence and abundance of Atlantic bluefin tuna (Thunnus thynnus) in the trap fishery of Sardinia (W Mediterranean)
No full textFrom April to June Atlantic bluefin tuna, Thunnus thynnus, migrate along the western Sardinian coastline in a southward direction, where they are intercepted by the trap fishery. Fishermen claim that Mistral episodes facilitate the entry of tuna schools towards the traps, thus increasing capture rates. To test the fishermen’s hypothesis we conducted underwater visual counts of tuna in the trap chambers and analysed these data under the effect of wind. The results indicate a “stair-step” pattern in the abundance of tuna, demonstrating that major increases in abundance are associated with the Mistral. The second analytical approach involved a longer time scale to test whether higher Mistral occurrences corresponded to periods when higher captures were recorded. Using a linear regression model we found a significant correlation (p15 knots seemed to have a negative effect on captures. This pattern may be caused by wind-induced advection of coastal waters generating a physical boundary that may have had a deterrent effect on tuna schools
Sustainable fishing in the Mediterranean for Bluefin Tuna: a case study of ancestral fishing technologies and contemporary practices
No full textGas chromatographic mass spectrometry determination of geosmin and 2-methylisoborneol off-flavor in Mugil cephalus roe
No full textBotargo is the product of the industrial management of fresh roe of the grey mullet (Mugil cephalus). This food product is actually obtained from wild fish caught in different marine areas around the word. The increasing commercial demand of botargo has brought to carry out different fishing systems, gathering the wild mullet in restricted areas, lagoons, to be caught if necessary. This operating mode has caused the appearance of new problems related to the organoleptic approval by the consumers of fish and derived products, following off-flavor contamination derived from different microorganisms present in the lagoons. The most important off-flavor compounds are represented by 2-methylisoborneol (2-MIB) and geosmin (GSM) which give a muddy/musty smell and flavor to the fish. A simple and easy-to-use GC/MS method for the determination of 2-MIB and GSM has been developed. The method has been validated with the following parameters: instrument limit of detection (LOD) and of quantification (LOQ), precision, recovery, and linearity. The method carried out showed good LOD of 1.0 μg/kg and LOQ 2.0 and 5.0 μg/kg for GSM and 2-MIB, respectively. Validation parameters were in close agreement with those reported in the EC SANCO/12571/2013. Recoveries ranged from 80.2 to 121.4 %, with percent relative standard deviation (RSD%) ranging from 0.6 to 18.6 % in the most unfavorable case. Real sample analysis showed the presence of residues of both off-flavor in all botargo samples analyzed, except for sample S0, while in fresh roe samples, only S7 showed important residues of 2-MIB
Anthropogenic impacts on the bluefin tuna (Thunnus thynnus L.) trap fishery of Sardinia (western Mediterranean)
No full textGas-Chromatographic mass spectrometry determination of geosmin and 2-methylisoborneol off-flavor in Mugil cephalus roe
No full textDifferential feeding rates of native and alien predators on the invasive Asian date mussel Arcuatula senhousia (Benson in cantor, 1842) in a Mediterranean coastal lagoon
No full textThe alien Asian date mussel Arcuatula senhousia inhabits several coastal environments worldwide. This species can form dense mats where individuals attach through byssus threads, thus altering the structure, functioning and biodiversity of the native communities. We investigated the feeding preference of different predators on this alien species in a Mediterranean coastal lagoon. To do this, a mesocosm experiment was conducted using two crab species (the Mediterranean green crab Carcinus aestuarii) and the Say mud crab Dyspanopeus sayi, and one gastropod, the banded dye-murex Hexaplex trunculus as predators of A. senhousia with or without byssus mats. Our data suggest that C. aestuarii is a more effective predator against A. senhousia than D. sayi, and that H. trunculus is almost ineffective. A possible implication of this result is the potential use of the native crab C. aestuarii for limit the formation of the byssus mats, thus mitigating their potential negative effects on the native communities
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