The MEDITS programme started in 1994 in the Mediterranean with the cooperation among research institutes from four countries: France, Greece, Italy and Spain. Over the years, until the advent of the European framework for the collection and management of fisheries data (the Data Collection Framework, DCF), new partners from Slovenia, Croatia, Albania, Montenegro, Malta and Cyprus joined MEDITS. The FAO regional projects facilitated the cooperation with non-European countries. MEDITS applies a common sampling protocol and methodology for sample collection, data storage and data quality checks (RoME routines). For many years, MEDITS represented the most important data source supporting the evaluation of demersal resources by means of population and community indicators, assessment and simulation models based on fishery-independent data. With the consolidation of the DCF, MEDITS routinely provides abundance indices of target species for tuning stock assessment models of intermediate complexity. Over the years, the survey scope has broadened from the population of demersal species to their fish community and ecosystems, and it has faced new challenges, such as the identification of essential fish habitats, providing new scientific insights linked to the Marine Strategy Framework Directive (e.g. biodiversity, trophic webs, allochthonous species and marine macro-litter evaluations) and to the ecosystem approach to fishery and marine spatial planning.

Comparativa de abundancias y biomasa de la ictiofauna profunda(200-1800 metros)de las proximidades de las islas Baleares. Mapas, gráficos y listado de especies.A total of 13 026 fishes belonging to 82 species and 43 famllies were collected in a continuous transect between depths of 200 and 1800 m south of the Baleanc Islands (Algerian basin, western Mediterranean). The analysis of 32 bottom trawls showed the existence of 4 groups associated with the upper slope (groups 1 and 2, from 200 to 400 and 400 to 800 m, respectivelv), middle slope (group 3, from 800 to 1400 m) and lower slope (group 4, below a depth of 1400 m) Thc differcnces in the mean values of the ecological parameters species richness, abundance, biomass and mean fish weight were also indicative of distinctive characteristics between these fish assemblages. Species richness decreased significantly with depth. The highest values of diversity corresponded to the samples from group 2. Biomass did not show any specific trend throughout the whole bathymetric range. Mean fish weight show 2 different trends along the continental slope: a bigger-deeper phenomenon at the upper 1000 to 1200 m depth. and a smaller-deeper phenomenon below this depth. Our results are compared with those obtained in the north Atlantic basin and in the western Mediterranean (Balearic basin), and the main factol-s affecting these deep-sea fish assemblages are discussed.EU FAIR PROJECT CT 95-0655. European Commission DC;-XIV, Fisheries.Peer reviewe

The identification of nursery grounds and other essential fish habitats of exploited stocks is a key requirement for the development of spatial conservation planning aimed at reducing the adverse impact of fishing on the exploited populations and ecosystems. The reduction in juvenile mortality is particularly relevant in the Mediterranean and is considered as one of the main prerequisites for the future sustainability of trawl fisheries. The distribution of nursery areas of 11 important commercial species of demersal fish and shellfish was analysed in the European Union Mediterranean waters using time series of bottom trawl survey data with the aim of identifying the most persistent recruitment areas. A high interspecific spatial overlap between nursery areas was mainly found along the shelf break of many different sectors of the Northern Mediterranean indicating a high potential for the implementation of conservation measures. Overlap of the nursery grounds with existing spatial fisheries management measures and trawl fisheries restricted areas was also investigated. Spatial analyses revealed considerable variation depending on species and associated habitat/depth preferences with increased protection seen in coastal nurseries and minimal protection seen for deeper nurseries (e.g. Parapenaeus longirostris 6%). This is partly attributed to existing environmental policy instruments (e.g. Habitats Directive and Mediterranean Regulation EC 1967/2006) aiming at minimising impacts on coastal priority habitats such as seagrass, coralligenous and maerl beds. The new knowledge on the distribution and persistence of demersal nurseries provided in this study can support the application of spatial conservation measures, such as the designation of no-take Marine Protected Areas in EU Mediterranean waters and their inclusion in a conservation network. The establishment of no-take zones will be consistent with the objectives of the Common Fisheries Policy applying the ecosystem approach to fisheries management and with the requirements of the Marine Strategy Framework Directive to maintain or achieve seafloor integrity and good environmental status.

New monitoring technologies are being progressively implemented in open-ocean and coastal observatories. The Mediterranean Sea is a well-known, reduced-scale ocean, an ideal natural laboratory to study global ocean processes, in particular those associated with meso- and submesoscale variability, interactions with mean flows and associated ecosystem response. SOCIB, the Balearic Islands Coastal Ocean Observing and Forecasting System, is one of such observatories, a multiplatform distributed and integrated system, a facility of facilities that extends from the nearshore to the open sea. SOCIB profits from the strategic position of the Balearic Islands at the Atlantic/Mediterranean transition area, one of the “hot spots” of biodiversity in the world’s oceans, and also of societal needs in islands where preservation of the environment is essential to assure both residents’ welfare and the competitiveness of the tourist sector. SOCIB is unique in that, from peer-reviewed excellence, its mission and objectives are science-, technology-, and society-driven. These types of new marine infrastructures, because of their critical mass and sustained funding, are presently establishing new ways of international cooperation, leading to major science breakthroughs, innovations in oceanographic instrumentation, and new ways of more efficient and science-based coastal and ocean management. We describe the major elements and structure of SOCIB and present some recent scientific, technological, and society-related results that are of relevance at a global ocean scale.

The demersal resources distributed in the trawl fishing grounds off the Balearic Islands (western Mediterranean) were studied from two bottom trawl surveys carried out in spring and autumn along the continental shelf and upper slope off the islands of Mallorca and Menorca. A total of 88 hauls, between 41 and 745 m depth, were analysed by means of multivariate analysis and ecological parameter calculation in order to characterise the structure of commercial species assemblages. A different bathymetric distribution of abundance was observed by comparing the main taxonomic groups. Six main species assemblages were identified, primarily associated with depth but also with different macro-epibenthic communities. Seasonal or geographic differences were detected for three of these assemblages, which could be related to differences in habitats and macro-epibenthic communities, as well as to seasonal changes in the abundance of some species related to their life cycle.