Macrophytobenthic colonization of artificial reefs in the Ligurian Sea (Loano-Savona)

Lo studio della composizione del popolamento macrofitobentonico su strutture artificiali sommerse ha una storia decennale nella zona di Loano (Savona). Il presente lavoro mira a presentare le osservazioni preliminari di una nuova campagna in corso di svolgimento nella medesima zona. La flora e la struttura della comunità macrofitobentonica viene analizzata sulle strutture artificiali (piramidi) posizionate nella zona di Loano ad una profondità di 18 m. Il confronto con i dati storici presenti in letteratura fornirà un quadro dell'evoluzione del popolamento su tali substrati

Marine alien species in Italy: A contribution to the implementation of descriptor D2 of the marine strategy framework directive

The re-examination of marine alien species or Non-indigenous species (NIS) reported in Italian Seas by December 2018, is here provided, particularly focusing on establishment success, year of first record, origin, potential invasiveness, and likely pathways. Furthermore, their distribution is assessed according to marine subregions outlined by the European Union (EU) Marine Strategy Framework Directive: Adriatic Sea (ADRIA), Ionian Sea and Central Mediterranean Sea (CMED), and Western Mediterranean Sea (WMED). In Italy, 265 NIS have been detected with the highest number of species being recorded in the CMED (154 species) and the WMED (151 species), followed by the ADRIA (143). Most of these species were recorded in more than one subregion. The NIS that have established stable populations in Italian Seas are 180 (68%), among which 26 have exhibited invasive traits.Among taxa involved, Macrophyta rank first with 65 taxa. Fifty-five of them are established in at least one subregion, mostly in the ADRIA and the CMED. Crustacea rank second with 48 taxa, followed by Polychaeta with 43 taxa, Mollusca with 29 taxa, and Pisces with 28 taxa, which were mainly reported from the CMED. In the period 2012-2017, 44 new alien species were recorded, resulting in approximately one new entry every two months. Approximately half of the NIS (~52%) recorded in Italy have most likely arrived through the transport-stowaway pathway related to shipping traffic (~28% as biofoulers, ~22% in ballast waters, and ~2% as hitchhikers). The second most common pathway is the unaided movement with currents (~19%), followed by the transport-contaminant on farmed shellfishes pathway  (~18%). Unaided is the most common pathway for alien Fisshes, especially in CMED. Escapes from confinement account for ~3% and release in nature for ~2% of the NIS. The present NIS distribution hotspots for new introductions were defined on the first recipient area/location in Italy. In ADRIA the hotspot is Venice which accounts for the highest number of alien taxa introduced in Italy, with 50 newly recorded taxa. In the CMED, hotspots of introduction are the Taranto and Catania Gulfs, hosting 21 first records each. The Strait of Sicily represents a crossroad between the alien taxa from the Atlantic Ocean and the Indo-Pacific area. In the WMED, hotspots of bioinvasions include the Gulfs of Naples, Genoa and Livorno.This review can serve as an updated baseline for future coordination and harmonization of monitoring initiatives under international, EU and regional policies, for the compilation of new data from established monitoring programs, and for rapid assessment surveys.

Estabilidad de las relaciones entre las agrupaciones de peces demersales y los factores ambientales-actividad pesquera a gran escala espacio-temporal en el norte del mar Mediterráneo

Trawling pressure and environmental changes may affect the composition of fish assemblages. Our knowledge on large spatio-temporal patterns of demersal fish composition remains incomplete for the Mediterranean Sea. We investigated (1) the spatio-temporal stability of demersal assemblages, (2) the relationships between these assemblages and potential structuring factors (trawling pressure and environmental conditions) in order to assess the dynamic of the assemblage structure at the scale of the northern Mediterranean Sea. We analysed a dataset of 18062 hauls from 10 to 800 m depth performed annually during the last two decades across 17 Geographical Sub-Areas (GSAs) (MEDITS program). A multi-table analysis (STATICO-CoA) evidenced a strong inter-GSAs stability in the organization of assemblages, with specificities for some GSAs. The most stable structuring factors were linked to combined gradients of chlorophyll a, phytoplancton carbon biomass and temperature, inversely correlated with depth, salinity and nutrient gradients (axis 1 of the STATICO-CoA compromise, 93.74% of the total variability). A common pattern linking the distribution of species to these environmental gradients was evidenced for most of the 17 GSAs. Estimate of trawling pressure showed a minor role in the organization of the assemblages for the spatial scale and years investigated (axis 2, 4.67%).La presión pesquera y los cambios ambientales pueden afectar a la composición de las agrupaciones de peces. En el Mediterráneo, nuestro conocimiento a gran escala sobre los patrones espacio-temporales de la composición de especies de peces demersales sigue siendo incompleto. Investigamos (1) la estabilidad espacio-temporal de las agrupaciones demersales (2) las relaciones entre dichas agrupaciones y los posibles factores estructurantes (presión pesquera de arrastre y condiciones ambientales) para evaluar la dinámica de la estructura de las agrupaciones en el norte del mar Mediterráneo. Analizamos un conjunto de 18062 lances entre 10 y 800 m. de profundidad realizados anualmente, durante las últimas dos décadas, en 17 sub-áreas geográficas (GSAs) (Proyecto MEDITS). El análisis multi-tablas (STATICO-CoA) evidenció una fuerte estabilidad inter-GSAs en la organización de agrupaciones, con especificidades para algunas GSAs. Los factores estructurantes más estables se relacionaron con los gradientes combinados de clorofila a, fitoplancton, carbono y temperatura, correlacionados inversamente con los gradientes de profundidad, salinidad y nutrientes (eje 1 del STATICO-CoA, 93.74% de la variabilidad total). En la mayoría de las GSAs encontramos un patrón común que vincula la distribución de las especies a estos gradientes ambientales. La estimación de la presión pesquera de arrastre mostró un papel menor en la organización de las agrupaciones para la escala espacial y los años investigados (eje 2, 4.67%)

Large-Scale Spatio-Temporal Patterns of Mediterranean Cephalopod Diversity

Species diversity is widely recognized as an important trait of ecosystems’ functioning and resilience. Understanding the causes of diversity patterns and their interaction with the environmental conditions is essential in order to effectively assess and preserve existing diversity. While diversity patterns of most recurrent groups such as fish are commonly studied, other important taxa such as cephalopods have received less attention. In this work we present spatio-temporal trends of cephalopod diversity across the entire Mediterranean Sea during the last 19 years, analysing data from the annual bottom trawl survey MEDITS conducted by 5 different Mediterranean countries using standardized gears and sampling protocols. The influence of local and regional environmental variability in different Mediterranean regions is analysed applying generalized additive models, using species richness and the Shannon Wiener index as diversity descriptors. While the western basin showed a high diversity, our analyses do not support a steady eastward decrease of diversity as proposed in some previous studies. Instead, high Shannon diversity was also found in the Adriatic and Aegean Seas, and high species richness in the eastern Ionian Sea. Overall diversity did not show any consistent trend over the last two decades. Except in the Adriatic Sea, diversity showed a hump-shaped trend with depth in all regions, being highest between 200–400 m depth. Our results indicate that high Chlorophyll a concentrations and warmer temperatures seem to enhance species diversity, and the influence of these parameters is stronger for richness than for Shannon diversityVersión del editor4,411

Demersal resources in the Mediterranean. Proceedings of the Symposium held in Pisa, 18-21 March 1998

In 1993, the European commission incited the scientific community to initiate a joint research programme to improve the knowledge of demersal resources in the Mediterranean by bottom trawl surveys. The symposium held in Pisa, March 1998, made a general survey of scientific advances obtained during the first three years of the ensuing international programme, enriched with experiments from other areas.En 1993, la Commission européenne a incité la communauté scientifique à lancer un programme de recherche commun basé sur des campagnes de chalutage de fond, pour améliorer les connaissances sur les ressources démersales en Méditerranée. Le symposium qui s'est tenu à Pise en mars 1998 a fait un tour d'horizon des principaux résultats scientifiques acquis par le programme international ainsi développé, enrichi d’expériences issues d'autres régions