Fish response to multiple anthropogenic stressors in mediterranean coastal lagoons: A comparative study of the role of different management strategies

Transitional waters are among the most productive ecosystems of the world and their biotic communities show high diversity and complex mechanisms of self-regulation that provide valuable ecosystem services and societal goods and benefits. In this work a comparison of the fish assemblages of three non-tidal Mediterranean coastal lagoons is carried out in order to evaluate the impacts of alternative management strategies. The anthropogenic pressures acting on the lagoons were quantified by means of categorical indicators, while the characteristics of the fish assemblages were summarized in multi-metric indices (MMIs). Two MMIs were developed using data collected with a beach seine net and with fyke nets, following an empirical approach that selects, from a pool of 73 metrics, the combination that maximizes the MMI/pressure relationship. The two MMIs include four metrics each, most of which are based on feeding mode functional guilds and habitat use functional guilds, and they are sensitive to anthropogenic pressures. The human activities directly or indirectly affecting water quality are the ones that most influence the fish assemblage, while the presence of artisanal fisheries, a typical and relevant resource use in these lagoons, seems to play a beneficial role. Lagoon fisheries management relies on the maintenance of infrastructures that guarantee the hydraulic functioning of the lagoon, thus ensuring exchanges with the adjacent coastal sea, and therefore indirectly contributing to the habitat quality

Growth of Wild Gilthead Seabream (Sparus aurata L.) Juveniles for Organic Aquaculture

The majority of organic marine fish farms currently begin the production cycle with non-organic juveniles from conventional hatcheries, permitted by the European Regulation on organic fish origin (EC 710/2009) until the end of 2016. Wild juvenile gilthead seabream (Sparus aurata) from coastal lagoons and hatcheries were experimentally reared under organic conditions, in order (1) to investigate differences in fillet lipid content and fatty acids composition, and (2) to propose a possible future source of juveniles destined for organic aquaculture. Wild juveniles were readily distinguishable by their fatty acid signature, showing significantly higher ratio levels of n-3 polyunsaturated fatty acids and n-3/n-6. Fillet lipid composition of organically fed wild S. aurata juveniles was preferable to that from domesticated juveniles. These results seem promising for organic aquaculture, where fish feed is more environmentally sustainable but is of lower nutritional qualit

Skin pigmentation in gilthead seabream (Sparus aurata l.) fed conventional and novel protein sources in diets deprived of fish meal

The pattern of yellowish pigmentation of the skin was assessed in gilthead seabream (Sparus aurata) fed for 12 weeks iso-proteic (45%) and iso-lipidic (20%) diets deprived of fish meal and containing either a blend of vegetable protein-rich ingredients or where graded levels of the vegetable protein blend were replaced by insect (Hermetia illucens\u201410%, 20% or 40%) pupae meal, poultry by-product meal (20%, 30% or 40%), red swamp crayfish meal (10%) and marine microalgae (Tisochrysis lutea and Tetraselmis suecica\u201410%) dried biomass. Digital images of fish fed diets differing in protein sources were analyzed by means of an automatic and non-invasive image analysis tool, in order to determine the number of yellow pixels and their dispersion on the frontal and lateral sides of the fish. The relationship between the total carotenoid concentration in the diet and the number of yellow pixels was investigated. Test diets differently affected gilthead seabream skin pigmentation both in the forefront and the operculum, due to their carotenoid content. The highest yellow pixels\u2019 number was observed with the diet containing microalgae. Fish fed poultry by-product meal were characterized by the lowest yellow pixels\u2019 number, diets containing insect meal had an intermediate coloring capacity. The vegetable control, the microalgae mix diet and the crayfish diet had significantly higher values of yellow pixels at both inspected skin sites

Fish Response to Multiple Anthropogenic Stressors in Mediterranean Coastal Lagoons: A Comparative Study of the Role of Different Management Strategies

Transitional waters are among the most productive ecosystems of the world and their biotic communities show high diversity and complex mechanisms of self-regulation that provide valuable ecosystem services and societal goods and benefits. In this work a comparison of the fish assemblages of three non-tidal Mediterranean coastal lagoons is carried out in order to evaluate the impacts of alternative management strategies. The anthropogenic pressures acting on the lagoons were quantified by means of categorical indicators, while the characteristics of the fish assemblages were summarized in multi-metric indices (MMIs). Two MMIs were developed using data collected with a beach seine net and with fyke nets, following an empirical approach that selects, from a pool of 73 metrics, the combination that maximizes the MMI/pressure relationship. The two MMIs include four metrics each, most of which are based on feeding mode functional guilds and habitat use functional guilds, and they are sensitive to anthropogenic pressures. The human activities directly or indirectly affecting water quality are the ones that most influence the fish assemblage, while the presence of artisanal fisheries, a typical and relevant resource use in these lagoons, seems to play a beneficial role. Lagoon fisheries management relies on the maintenance of infrastructures that guarantee the hydraulic functioning of the lagoon, thus ensuring exchanges with the adjacent coastal sea, and therefore indirectly contributing to the habitat quality

Population structure and dynamics of the invasive Procambarus clarkii (Girard, 1852) in a Tiber river Ramsar site, Central Italy

Procambarus clarkii is a native species of Central America, but strongly invasive in many regions of the world. An investigation on the red swamp crayfish was carried out to obtain more information about its population dynamics in the Tiber River, in Central Italy. A total of 900 individuals, both males and females, were sampled within two different campaigns (2017 and 2019) aimed at collecting biometric data. A strong fishing effort was deployed (more than 100 nets set), to guarantee a large and randomized number of samples. The crayfish populations were grouped into seven different cohorts, according to Bhattacharya's method. The population showed a balanced sex ratio, the average cephalothorax length was 42.52 mm, with the most represented size class between 40-50 mm. K and L∞, as well as the growth parameter index (í˜), the mortality rate (Z), and longevity value (tmax), were calculated. K and í˜ values resulted very high, showing an impressive growth rate in the study area; tmax ranged from 4 to 5 years, L∞ values were lower compared with other studies (58.0-59.0 mm), while Z was very high for this population (4.2-4.5 year). The results revealed that crayfish population dynamics can be complex and vary depending on habitat type, available trophic resource and competition

Insights into different marine aquaculture infrastructures from a life cycle perspective

Aquaculture facilities represent an often-neglected process in environmental impact studies. This study focus on the environmental impact assessment of alternative net materials in Mediterranean marine aquaculture. A Life Cycle Assessment was conducted using primary and secondary data from specific databases and literature. Three baseline scenarios were compared: copper alloy net cages with 100 % of recycled material (CAN100), 75 % of recycled material (CAN75), and polyethylene net (PEN) System boundaries include manufacturing and disposal of cages, nets, and mooring system. The use and emissions of antifouling paints and CAN were considered. Sensitivity analysis of the most impacting sub-processes and Uncertainty analysis were also conducted. The use of CAN is advantageous in terms of environmental impact, but only considering a complete recyclability of the net at the end of its service life. Moreover, when considering a reduced service life of the PEN due to the detrimental effect of biofouling, the advantage of the CAN is even more evident. To counteract the negative effect of biofouling, copper-based antifouling paints are generally used in marine aquaculture. These products are a main environmental hotspot in PEN systems. Therefore, a higher consumption of such products could determine an environmental burden shifting from CAN to PEN ones. So far, CAN are not widespread in the aquaculture industry, mainly due to the high cost of initial investment compared to traditional PEN. Considering operational and environmental advantages, CAN cages could represent an affordable and resilient solution for aquaculture enhancing environmental, economic, and social performances of this industr

APPRENDRE DU PASSE POUR OPTIMISER LA PREVENTION ET LA GESTION DES INONDATIONS SUR LE FERROVIAIRE

International audienceArchives records dealing with historical floods constitute a remarkable heritage for railway system analysis, but they are under-exploited. This article deals with their interest. Then a methodology to build a chronological synthesis from historical records is presented. Finally, the advantages of geovisualisation, as a tool to ease the exploitation of historical information, are presented.Les archives sur les inondations historiques constituent un patrimoine riche pour l'analyse du système ferroviaire, mais actuellement sous-exploité. Nous expliquons ce qu'elles peuvent apporter, puis nous présentons une méthode de synthèse des données issues d'archives. Enfin, nous présentons les apports de la géovisualisation, comme outil pour faciliter l'utilisation de l'information historique

No apparent genetic bottleneck in the demographically declining European eel using molecular genetics and forward-time simulations

No apparent genetic bottleneck in the demographically declining European eel using molecular genetics and forward-time simulations