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SUMMARY: The coastal demersal fish assemblage exploited commercially by the Viareggio fleet was assessed in order to define its exploitation status and sustainability. A production model was used provided management benchmarks for the species for which available data are limited. The ASPIC Surplus production model was used. The results showed a depleted population for most of the species involved (B 2008 /B 0 between 0.05 and 0.35) with high relative fishing mortality (F 2008 /F MSY between 1.18 and 1.64). Population projections using ASPIC-P allowed the exploitation strategies to be evaluated for a 10-year period. None of the populations are predicted to recover to B MSY if fishing effort remains at the 2008 levels. A reduction in effort of about 40% should increase the biomass in the medium-term of most of the species to B MSY or over, with a fairly good increase in yields of the most valuable species.Keywords: NW Mediterranean, multispecies fisheries, production models, stock assessment, commercial fisheries, forecasting.RESUMEN: Evaluación del estado de los estocs costeros explotados por la flota de Viareggio (Mar Ligur meridional). -El conjunto de especies costeras explotado comercialmente por la flota de Viareggio fue evaluado para definir su estado de explotación y sostenibilidad. El uso de un modelo de producción permitió definir pautas de manejo pesquero para estas especies para las que los datos disponibles son limitados. Se utilizó el modelo de producción excedente ASPIC. Los resultados mostraron para la mayoría de las especies, biomasas drásticamente reducidas (B 2008 /B 0 entre 0.05 y 0.35) con altos valores relativos de mortalidad por pesca (F 2008 /F MSY entre 1.18 y 1.64). Proyecciones realizadas con ASPIC permitieron evaluar estrategias de explotación para un periodo de diez años. Manteniendo el esfuerzo a nivel del 2008, para ninguna especie se prevé que la recuperación de la población alcance el nivel de B MSY . Una reducción del esfuerzo del 40% debería conducir a un incremento, a medio plazo, de la biomasa de casi todas las especies por encima del B MSY, incrementán-dose asimismo sustancialmente los rendimientos de las especies más importantes.Palabras clave: Mediterráneo nord-occidental, pesquerías multiespecíficas, modelos de producción, evaluación de estocs, pesca comercial, proyecciones.

Coralligenous reefs are the main biogenic constructions of the Mediterranean Sea. The two main coralligenous morphologies are cliffs and platforms. Coralligenous cliffs mostly develop in shallower waters (about 20-50 m) on vertical/sub vertical rocky substrates. Coralligenous platforms are mostly distributed on horizontal substrates below 40-50 m depth on detritic bottoms and rocky outcrops of the continental shelf. The present study aims at contributing to the knowledge of coralligenous cliffs through the assessment of their distribution and extent in a wide geographic zone of northwestern Mediterranean Sea, focusing on the structure and the spatial variability of the associated assemblages. To achieve these objectives, coralligenous cliffs of Tuscany coasts were mapped through Multibeam and Remotely Operated Vehicles. The area of coralligenous cliffs was also manually calculated for each study site using linear extent and bathymetric range of the habitat. In addition, the structure of the associated assemblages was investigated by a multifactorial sampling design taking into account spatial scales ranging from meters to tens of kilometres. Coralligenous cliffs were present in all the study sites, with a linear extent of about 20% of Tuscany’s rocky coastline and an area of about 20% of the Tuscan coralligenous reefs. The difference between data manually calculated and those obtained by Quantum- GIS software was about 33% of the total area. A continental-to-island gradient and a latitudinal gradient were the main factors driving the structure of the associated assemblages. Results highlighted that coralligenous cliffs represent a considerable part of circalittoral biogenic habitat, suggesting that their relevance may be greater than what normally emerges from seabed mapping and that they should be considered separately in monitoring programs, impact assessment studies and management plans.

The present study aims at assessing the distribution and extension of the coralligenous cliffs in Tuscany and describing the structure and the patterns of spatial variability. The mapping of seabed was obtained through Multibeam echosounder data coupled with video images. Coralligenous cliffs were sampled by SCUBA divers in 11 sectors of rocky costs following the STAR procedure. Coralligenous cliffs were present in all study sites, with a total length of about 62.5 km and a total surface of 0.47 km2. The linear extension of the habitat may be estimated about the 20% of Tuscany rocky coast.