Search

Fisheries are among the human activities that are most strongly affected by ongoing climate-related changes in the presence and abundance of fish species across the globe. The ecological and social repercussions of such changes for recreational fisheries are however still poorly understood. Here, we compare selected ecological and social dimensions of both recreational angling and spearfishing targeting the bluefish (Pomatomus saltatrix) in Italy. The bluefish has undergone a northward expansion in the region over the last 20–30 years, during which it reached new areas and increased in abundance. Using digital videos and their associated data published by both recreational anglers and spearfishers on YouTube we characterized ecological and social dimensions using a culturomics approach. Specifically, we focused on harvesting patterns, social engagement and sentiments related to the bluefish. Our study revealed four major results: (1) similar harvesting patterns (i.e., declared mass and seasonal upload patterns) related to videos by both recreational anglers and spearfishers; (2) higher social engagement (i.e., number of views and likes) for videos by recreational anglers than spearfishers; (3) differences in themes of discussion, with anglers being mainly interested in fishing strategy and gears and spearfishers being more interested in fishing actions shown on the videos; (4) positive and negative sentiments of both recreational anglers and spearfishers towards the invasiveness and aggressiveness of the species. The latter represents an interesting trade-off associated with recreational fishing of the bluefish: it is perceived as an invasive species, but it is also a valued target fish because its voracity contributes to the quality of the recreational fishing experience. Our study showcases the value of exploring social media and associated data to better understand the ecological and human dimensions of marine recreational fisheries in relation to distributional range shifts of species associated with climate change. [ABSTRACT FROM AUTHOR]

Volatiles are critical for real and perceived quality of mussels. In the present study, we determined, for the very first time, the characteristic volatiles of fresh Mediterranean mussels (Mytilus galloprovincialis) and their variation during 4 days of storage at 6.0 ± 0.5 °C. During this time, volatile organic compounds (VOCs) were monitored using SPME-GC-MS. Twenty-seven VOCs were identified in mussel meat: eight esters, seven alcohols, three acids, three aldehydes, three ketons, one phenol, one sulfide, and one polycyclic aromatic hydrocarbon. While the molecular fingerprint of the fresh mussel was very simple, during storage, there was the onset of reliable shelf life markers. Two of them, namely 1-octen-3-ol and 2-nonanone, appeared after 1.5 days and increased during chilled storage up to the fourth day. Other seven compounds (three free acids, four esters, and one phenol derivative) were found only after 4 days. Shelf life markers monitoring enables correct transport and storing conditions and prevention of the distribution of stale mussels. This issue is obviously crucial for the food industry and catering. The technique is a rapid, green, and nondestructive monitoring tool during ongoing development of industrial food processing. The absence of sample manipulation assures the fact that its flavor is not influenced by pre-analytical steps. It could aid in the development of technologies that monitor and improve the processing product quality and consistency. [ABSTRACT FROM AUTHOR]

A pregrowing trial was carried out using nursery-stage cupped oyster ( Crassostrea gigas) in order to evaluate weight, length, mortality, and final costs of spat grown in long-line aquaculture at different sampling times (t1-t5) over 81 days. Spat were reared at two stocking densities in polyvinyl chloride cylinders (10 cm diameter, 24 cm length) placed within lanterns composed of five levels (60 cm diameter, 11 cm height). Each lantern level hosted two cylinders. Lanterns were hung 6 m below the surface of the water in the Middle Adriatic Sea. A total of 53,100 spat (weight 0.033 g, length 5 mm) were divided into seven cylinders at either high density (H; 5055 oysters/cylinder, 167.3 g/cylinder) or low density (L; 2530 oysters/cylinder, 83.7 g/cylinder). On the basis of the ANOVA analysis, spat were significantly heavier (0.352 vs. 0.227 g; P < 0.001) and longer (12.22 vs. 10.47 mm; P < 0.001) in the L group compared to the H group. Considering the time factor, oysters were significantly heavier (0.941 g; P < 0.001) and longer (21.30 mm; P < 0.001) at t5 than at any previous sampling time (t1-t4). A higher rate of mortality was initially observed in the L group (6.7% at t1); however, mortality in the H group was higher at later sampling dates, reaching the highest level at t4 (32.4%). Spat grew better at the low stocking density, demonstrating that a higher stocking density is not suitable. [ABSTRACT FROM AUTHOR]

Aloes are now considered a very interesting source of bioactive compounds among which phytosterols should play a major role. The present study is an attempt to investigate the hypocholesterolemic activity of Aloe vera associated with its impact on the reproductive status of juvenile goldfish. Therefore, the short- and long-term effects of feeding supplementary diet containing aloe components (20 mg aloe/g diet; 2 %) on plasma lipids, plasma vitellogenin, and hepatic estrogen receptor α/β1 mRNA levels in goldfish were examined. Results of GC-MS for phytosterols show high abundance of β-sitosterol in freeze-dried powder of Aloe vera whole leaves. Moreover, a 2 % aloe powder dietary supplement was not found estrogenic in juvenile goldfish after either 7- or 30-day treatment, but was consistent in plasma hypocholesterolemic effects following long-term exposure. The present data further support that plasma cholesterol modulation induced by phytosterols may not be related to estrogen-like activity. [ABSTRACT FROM AUTHOR]

We propose the use of ultrasound pulsed echography (UPE) for the mapping of the leading edge cavitation pattern, in view of its application to full-scale measurements on propeller blades aboard a ship in actual service. Measurements are done on a two-dimensional NACA16009 hydrofoil, and a comparison is performed against a well-tested technique based on laser light scattering imaging. On a reference solid surface, the mean location of the surface is recovered within ±0.5 % of the foil maximum thickness, against ±0.1 % for the imaging technique. In terms of uncertainty, UPE displays error levels four to six times higher with respect to the reference imaging data. In presence of cavitation, the UPE approach tends to overestimate the thickness dimension of the vapor volume as a result of its sensitivity to noise scattering from wall reverberation and from particles in the bulk fluid. However, the overall performance is highly satisfactory for a potential use in a full-scale context, and specific improvements are suggested to fulfill this long-term goal. [ABSTRACT FROM AUTHOR]