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In the first half of the nineteenth century, industrialization increased the demand for sponges extracted by the sponge fishermen of the Dodecanese Archipelago in the Aegean Sea. This had widespread repercussions, leading to increasing numbers of sponge fishermen, the geographical expansion of fishing zones and the evolution and diversification of fishing techniques. In this context, foreign sponge traders imposed the hard-hat diving suit, which enabled divers to remain underwater for several hours without surfacing. It was therefore perceived as being more efficient than traditional skin-diving. But this equipment greatly exacerbated the physical risks faced by the divers, with injuries and fatalities increasing markedly. It also required heavy financial investments that compounded the losses of fishermen and their families. With hindsight, these investments were catalysts of the major socio-economic upheaval that followed. As well as provoking mass revolt among the islanders of the Dodecanese, this entailed modifications in crews and community structure as a nascent model of capitalist organization marked the development of the sponge fishery. [ABSTRACT FROM AUTHOR]

An overview is proposed of the hexactinellid sponge fauna of the Mediterranean Sea, including the description of a new species of Sympagella, S. delauzei sp. nov., collected by ROV during the exploration of deep-sea canyons of the NW Mediterranean and of deep banks and seamounts of the Alboran Sea. The type species of Sympagella, S. nux, is redescribed from specimens from the type locality. An 18S rDNA sequence of the new species was obtained and included in a phylogenetic tree of related hexactinellids. Some modifications to the classification of Rossellidae are proposed according to the new morphological and molecular data obtained during this study: the genera Caulophacus, and Caulophacella are accordingly moved from Rossellinae to Lanuginellinae. [ABSTRACT FROM PUBLISHER]

Marine cave communities have been a continued source of ecological surprises, among other things because of their close ecological and evolutionary ties with the deep sea. The discovery of cladorhizid sponges, the deepest occurring poriferan family, in shallow Mediterranean caves in the 1990s was one such surprise, leading to the generally accepted hypothesis that the whole family was carnivorous, an unprecedented feeding mode for sponges. The recent observation of the cave species Asbestopluma hypogea in the Mediterranean bathyal, confirmed the view that some shallow caves can occasionally shelter otherwise deep-dwelling species. Here we present new distribution data of A. hypogea, from deep Mediterranean locations, and for the first time from Atlantic locations. Among the new Atlantic records, the most surprising ones are located in three different geographic areas (Ria de Arousa, Groix Island and Cherbourg) of the NW European coasts, from the Iberian Peninsula to the English Channel, where A. hypogea reaches SCUBA depths (5-50 m), while not sheltered in marine caves. The carnivorous sponge however reaches its shallowest occurrence (5 m), in a small cave at Groix Island. The ecological significance of these discoveries, particularly the very patchy distribution and peculiar dynamics, are noteworthy, and the shallow occurrence of A. hypogea, together with other deep-water or uncommon species, constitute unique assemblages that must be considered in conservation plans. [ABSTRACT FROM AUTHOR]

During the exploration of the NW Mediterranean deep-sea canyons (MedSeaCan and CorSeaCan cruises), several hexactinellid sponges were observed and collected by ROV and manned submersible. Two of them appeared to be new species of Farrea and Tretodictyum. The genus Farrea had so far been reported with doubt from the Mediterranean and was listed as "taxa inquirenda" for two undescribed species. We here provide a proper description for the specimens encountered and sampled. The genus Tretodictyum had been recorded several times in the Mediterranean and in the near Atlantic as T. tubulosum Schulze, 1866, again with doubt, since the type locality is the Japan Sea. We here confirm that the Mediterranean specimens are a distinct new species which we describe. We also provide18S rDNA sequences of the two new species and include them in a phylogenetic tree of related hexactinellids.

Increasing anthropogenic pressures urge enhanced knowledge and understanding of the current state of marine biodiversity. This baseline information is pivotal to explore present trends, detect future modifications and propose adequate management actions for marine ecosystems. Coralligenous outcrops are a highly diverse and structurally complex deep-water habitat faced with major threats in the Mediterranean Sea. Despite its ecological, aesthetic and economic value, coralligenous biodiversity patterns are still poorly understood. There is currently no single sampling method that has been demonstrated to be sufficiently representative to ensure adequate community assessment and monitoring in this habitat. Therefore, we propose a rapid non-destructive protocol for biodiversity assessment and monitoring of coralligenous outcrops providing good estimates of its structure and species composition, based on photographic sampling and the determination of presence/absence of macrobenthic species. We used an extensive photographic survey, covering several spatial scales (100s of m to 100s of km) within the NW Mediterranean and including 2 different coralligenous assemblages: Paramuricea clavata (PCA) and Corallium rubrum assemblage (CRA). This approach allowed us to determine the minimal sampling area for each assemblage (5000 cm(2) for PCA and 2500 cm(2) for CRA). In addition, we conclude that 3 replicates provide an optimal sampling effort in order to maximize the species number and to assess the main biodiversity patterns of studied assemblages in variability studies requiring replicates. We contend that the proposed sampling approach provides a valuable tool for management and conservation planning, monitoring and research programs focused on coralligenous outcrops, potentially also applicable in other benthic ecosystems.