Age and total length (L T ) data from a 11 year monitoring of the Anguilla anguilla eel population of the Camargue lagoons (Rhoˆne delta, southern France) were collected for glass, yellow and silver eels. Three distinct models were calibrated to describe the growth process of undifferentiated eels, females and males, respectively. Uncertainty of parameter estimates was evaluated by bootstrapping. Females were characterized by larger asymptotic body size (L T ) than males (580 AE 50 v. 388 AE 13 mm) and faster growth, whilst the Brody growth coefficient was larger for males than for females (means AE S.D. 3Á00 10 À3 AE 1Á68 10 À3 v. 1Á73 10 À3 AE 0Á50 10 À3). Sexual differentiation was estimated to begin at 204 AE 38 mm mean AE S.D., i.e. at the end of the second year in the lagoons, well before the L T at which macroscopic differentiation became possible (c. 300 mm). Males probably leave the lagoon or die (due to either natural or fishing mortality) within the first 3 years, whilst females can remain up to 5 years. Sexual differentiation and maturation have a major role in shaping the L T structure of the population. The L T and mass (M) data were fitted by allometric curves M ¼ aL T b À Á . The calibration of distinct curves for data from different years indicated that the allometric coefficient a was subject to wider interannual fluctuations than the allometric exponent b. A negative correlation linked the average L T and the allometric exponent (r ¼ À0Á58, P < 0Á01).

Identifying factors and processes influencing natural mortality is fundamental to the understanding of population dynamics. Metabolic theory of ecology and experimental studies at the cross-species level suggest the existence of general patterns linking natural mortality to body mass and temperature. However, there is scant evidence that similar relationships also hold at the intra-specific scale, possibly because of the relatively narrow range of sizes and temperatures experienced by most species and the effect of local adaptation, which can obscure links between temperature and vital rates. In this sense, the European eel Anguilla anguilla, a panmictic species with a wide distribution range, provides a paradigmatic case. We compiled data published in the past 30 years on eel mortality during the continental phase of the life cycle for 15 eel stocks and calibrated a general model for mortality, considering the effects of body mass, temperature, stock density and gender. Estimated activation energy (E = 1.2 eV) was at the upper extreme reported for metabolic reactions. Estimated mortality rates (ranging between 0.02 year(-1) at 8°C, low density and 0.47 year(-1) at 18°C, high density for a body mass of 100 g) were appreciably lower than those of most fishes, most likely due to the exceptionally low energy-consuming metabolism of eel.

Aim: To explore the patterns of connectivity between marine protected areas (MPAs) and neighbouring non-protected areas and the scale at which the benefits of MPAs are expected using the white sea bream as model species. Location: Marine protected area of Torre Guaceto (TGMPA, Italy) in the south Adriatic Sea. Methods: A multidisciplinary approach was used combining (1) a genetic survey using 12 highly informative microsatellite loci of samples collected within the MPA and in several locations up to 100 km from the MPA; and (2) larval trajectories using Lagrangian simulations based on an oceanographical model of the region that includes specific data on early life-history traits. Both genetic and simulation studies were temporarily replicated during two consecutive years. Results: The overall genetic homogeneity observed indicates that the TGMPA is not isolated and that there is genetic connectivity among locations across a scale of at least ~200 km. A high degree of connectivity between the TGMPA and neighbouring areas is in agreement with Lagrangian simulations, which indicate that white sea bream larvae can be transported over large distances up to about 300 km. Trajectories released from the TGMPA showed that on average, 12.75% of the larvae remains within the TGMPA, while the rest travel south towards non-protected areas. Main conclusions: Our findings highlight the potential benefits of effectively enforced MPAs for neighbouring or relatively distant non-protected fishing areas and the potential connection with other MPAs at regional scale. Combining genetics and modelling can provide a general framework to investigate the role of connectivity in MPA design that can be easily extended to other species and geographical areas

Hempcrete is a natural building material that, in recent years, has known an increased popularity in a number of European countries. Hempcrete-based construction materials are used in non-bearing walls, as finishing plasters and floor/roof insulators. In the present work, the environmental performances of a non-load-bearing wall made of hempcrete blocks were assessed via Life Cycle Assessment (LCA). The analysis encompassed the whole life cycle but the end of life, due to the lack of reliable data for this stage. The production phase of the raw materials was identified as the main source of environmental impacts, but the transport distance of raw materials, as well as the amount and composition of the binder mixture, can considerably affect the results. An experimental assessment (via X-ray Powder Diffraction analysis) of the carbonation process taking place within the binder during the use phase of the wall showed that the carbonation rate may be smaller than assumed in previous works: after 240 d, only the outermost layers of the blocks showed significant levels of carbonation, while the innermost layers experienced only a negligible increase in the amount of carbonates. Nevertheless, the overall emission balance is very favourable: thanks to biogenic CO2 uptake during hemp growth and to CO2 uptake by carbonation, hempcrete blocks have a negative carbon footprint and act therefore as effective carbon sinks

Seascape connectivity critically affects the spatiotemporal dynamics of marine metacommunities. Understanding how connectivity patterns emerge from physically and biologically-mediated interactions is therefore crucial to conserve marine ecosystem functions and biodiversity. Here, we develop a set of biophysical models to explore connectivity in assemblages of species belonging to a typical Mediterranean community (Posidonia oceanica meadows) and characterized by different dispersing traits. We propose a novel methodological framework to synthesize species-specific results into a set of community connectivity metrics and show that spatiotemporal variation in magnitude and direction of the connections, as well as interspecific differences in dispersing traits, are key factors structuring community connectivity. We eventually demonstrate how these metrics can be used to characterize the functional role of each marine area in determining patterns of community connectivity at the basin level and to support marine conservation planning.