The European Union Common Fisheries Policy has established a discard ban, which states that fish below a reference size cannot be sold directly for human consumption. In a fishing effort-regulated fishery, the discard ban can result in extra handling, storing and landing costs. In an output-regulated fishery, this policy might also limit the effort levels as all the catches count against the quota. In both cases, this regulation can reduce the economic performance of the companies, even in single-species fisheries. A possible solution is to increase the mesh size, thus retaining fewer small individuals. To study this option, a bioeconomic simulation of a change in the gear selectivity from 100- to 120-mm minimum mesh size (MMS) was performed. The results show that the private perspective (profits) does not change. Furthermore, due to the lower retention of 120 mm MMS, the efficiency of a fishing day was reduced by 5% and 2.5%, from the point of view of capital and labour productivity, respectively. In contrast, gross revenues increased by 1.5% and crew compensation by 2%. Given a societal benefit of this change in the mesh size, this gain could be re-distributed to provide an incentive for selectivity improvements.

This study deals with the distribution of the species of the genus Alvania along the Turkish Aegean coast. The investigated material was collected from different habitats (soft and hard bottoms, and macrophyte beds) at a depth range of 0-875 m, at 39 stations along the Aegean coast of Turkey between 1995 and 2014. Among the analysed benthic material, 537 living specimens and 249 empty shells belonging to 20 species of the genus Alvania were obtained. Alvania marmarisensis is described as a new species. Alvania hispidula was recorded for the first time from the Turkish Aegean coast. Alvania mamillata was found to be the most widely distributed species in the study area, while Alvania colossophilus was the rarest one. Alvania cimicoides and Alvania testae were found in the deepest samples (between 93 and 875 m). Certain taxonomic and ecological characteristics of the identified species, along with photographs, are also provided.

To examine the extent to which human activities near the Ria Formosa coastal lagoon influence the accumulation of trace elements (TE) in Ruditapes decussatus, individuals were transplanted from a natural bank located in the lower lagoon to three sites located in clam growth grounds under the influence of a small city (Faro), a fish farming centre (Olhão) and a site near the lagoon inlet (Lavajo). Concentrations were determined in substrate of the clam grounds and in the digestive gland, gills, mantle plus siphons, and remaining tissues of clams in four periods of the year. These measurements were accomplished with the monthly survey of the gametogenic stages, condition index, proteins, glycogen, total lipids, pH and osmolarity of hemolymph. Arsenic, Cu, Mn, V, Cr and Pb were preferentially linked to the digestive gland, while Cd was linked to the gills. TE concentrations in the digestive gland and remaining tissues were higher in winter, most likely reflecting additional inputs associated with rain. The lack of disruptions in biological parameters and the prolonged period of spawning and gonad recovery in clams suggest that the current TE availability in the lagoon has a minor influence on the reproductive cycle and hence on clam production.

El índice ESCA (Estado Ecológico de las Comunidades Coralígenas) ha sido desarrollado para determinar el estado ecológico de los hábitats coralígenos utilizando macro-algas como indicador biológico. El objetivo de este estudio fue evaluar la respuesta, ante presiones antropogénicas, de macro-algas y macro-invertebrados sésiles moldeadores de la comunidad coralígena y su sensibilidad al índice ESCA. Se muestrearon comunidades coralígenas en 15 localizaciones del Mediterráneo Nord-Occidental clasificadas en 3 grupos: i) áreas marinas protegidas; ii) poco urbanizadas; iii) muy urbanizadas. Un valor de Nivel de Sensibilidad fue asignado a cada taxón/grupo en base a su abundancia en cada condición medioambiental, a información bibliográfica disponible y a los resultados de juicios por parte de expertos. El índice que integra la totalidad de las comunidades (llamado ESCA-TA), calculado usando tanto macro-algas como macro-invertebrados sésiles, detectó los diferentes niveles de presión humana de manera más precisa que el índice calculado solo con macro-algas o solo con invertebrados. El potencial para determinar el estado ecológico de las áreas marinas protegidas se incrementó con el índice ESCA-TA gracias al uso de una mayor variedad de descriptores.

We studied the habitat structure (macrofaunal assemblages and bottom types) and zonation patterns of 29 unvegetated shoreline strands along the 900-km coast of Catalonia (NW Mediterranean Sea). Organisms were sampled with grabs, pitfall traps, sticky traps, clam nets and spades to ensure capture of the different proportions of macrofaunal assemblages from the supra-, medio- and infralittoral levels. We collected 211 taxa: 194 animals and 17 algae. The most abundant and dominant organisms collected with van Veen grabs were Nematoda, Oligochaeta and Collembola at the supralittoral level; the polychaetes Saccocirrus spp. and Pisione remota, the amphipod Corophium orientale, Nematoda, and Turbellaria at the mediolittoral level; and Nematoda at the upper infralittoral level. SIMPER analysis revealed great dissimilarity between the organisms inhabiting the supralittoral and the other littoral levels. Regarding the epifauna, the sticky traps used at the supralittoral level mainly collected Collembola, which were nearly absent in pitfall traps. The qualitative study performed with a clam net and a small spade revealed that Nematoda, Saccocirrus spp., Turbellaria, Nemertea and the polychaete P. remota were the most abundant animals at both the medio- and the infralittoral levels and no differences were found between these levels. Different qualitative sampling methodologies showed that in fine sediments the bivalves Donax trunculus and D. semistriatus determined more than 97% of dissimilarity from coarse-sand sites. Richness increased in protected sandy and cobble shores. Littoral level and bottom-type features were only to a certain extent valid indicators of specific biotic components for a specific habitat.

This study presents a bioeconomic analysis of artificial shelter performance in a fishery targeting a spiny lobster meta-population, with spatially allocated, individual exclusive benthic property rights for shelter introduction and harvest of species. Insights into fishers’ short-run decisions and fishing strategies are also provided. Spatiotemporal bioeconomic performance of shelters located in ten fishing areas during four seasons was compared using two-way ANOVAs and Pearson correlations. Results show that there was spatiotemporal heterogeneity in bioeconomic variables among fishing areas, with mean catch per unit effort (CPUE, kg shelter–1) ranging from 0.42 kg to 1.3 kg per trip, mean quasi-profits of variable costs per shelter harvested ranging from USD6.00 to USD19.57 per trip, and mean quasi-profits of variable costs ranging from USD338 to USD1069 per trip. Positive moderate correlations between shelter density and CPUE (kg shelter–1 km–2) were found. Bioeconomic performance of the shelters was influenced by spatiotemporal resource abundance and distribution, fishing area location in relation to the port, shelter density, heterogeneous fishing strategies and the management system. The results provide empirical information on the spatiotemporal performance of shelters and fishing strategies and can contribute to management at the local-scale of a meta-population distributed throughout the Caribbean Sea and Gulf of Mexico.

We investigated the variability in the mesoscale distribution of the siphonophore Muggiaea atlantica and the hydromedusa Aglaura hemistoma in relation to the rapid spatial oscillations of the shelf-slope front off the Catalan coast (NW Mediterranean). Three extensive surveys were carried out in spring at ten-day intervals. High variability in the position of the front resulted from the advection of low-salinity waters originating in the Gulf of Lions, mainly from the Rhône River runoff. High spatial variability in the distribution of the two species was closely related to the shifting positions of the front. Both species occurred on its inshore side in much higher abundances than on its offshore side, where they were scarce or absent. The front acts as a barrier limiting offshore displacement of these two cnidarians. Statistical analyses showed that bottom depth and salinity, as independent variables, were indicators of the signature and position of the front, explaining most of the variance in the distribution and abundance of the two species.

Inciarte was born in Barcelona on