Esponjas como “hoteles vivientes” en cuevas submarinas del Mediterráneo

Although sponges constitute the dominant sessile organisms in marine caves, their functional role as ecosystem engineers has received little attention in this habitat type. In this study the associated macrofauna of the massive/tubular ecosystem-engineering sponges Agelas oroides and Aplysina aerophoba was studied across distinct ecological zones of two eastern Mediterranean caves. Our results revealed that the examined sponges supported a considerable associated macrofauna. A total of 86 associated taxa were found, including species reported for the first time as sponge symbionts and typical cave dwellers. Crustaceans predominated in terms of abundance but polychaetes showed the highest number of taxa. A clear differentiation was observed in the structure of the associated assemblage between the two sponges, attributed not only to the sponge species but also to differences in the surrounding environment. Density, diversity and the trophic structure of the sponge-associated macrofauna did not vary significantly along the horizontal axis of the surveyed caves. These findings suggest that sponges form a quite stable habitat, maintaining their functional role as ecosystem engineers across the studied marine caves and increasing habitat complexity in the impoverished inner dark cave sectors.A pesar de que las esponjas constituyen el grupo sésil dominante en cuevas submarinas, su papel como ingenieros del ecosistema dentro de estos ambientes ha recibido muy poca atención. En el presente trabajo, se ha estudiado la macrofauna asociada a las especies Agelas oroides y Aplysina aerophoba (ambas con una morfología masiva-tubular y consideradas como especies ingenieras del ecosistema) a lo largo de diferentes ambientes situados en dos cuevas marinas del Mediterráneo oriental. Nuestros resultados ponen de manifiesto que las dos especies de esponjas consideradas albergan una abundante fauna asociada. Se encontró un total de 86 taxones diferentes, muchos de los cuales son citados por primera vez como simbiontes de esponjas y habitantes de cuevas submarinas. Aunque los crustáceos fueron el grupo dominante en términos de abundancia, fueron los poliquetos los que presentaron la mayor riqueza taxonómica. Las comunidades asociadas a una y otra esponja presentaron claras diferencias, lo cual se atribuye no solo a diferencias relacionadas con las especies hospedadoras sino también al ambiente circundante. La densidad, diversidad y estructura trófica de la macrofauna asociada a las esponjas no varió significativamente a lo largo del eje horizontal de las cuevas muestreadas. Estos resultados sugieren que las esponjas forman un hábitat bastante estable, manteniendo su papel funcional como ingenieros del ecosistema a lo largo de las cuevas submarinas y, por tanto, incrementando la complejidad del hábitat en los sectores más internos, empobrecidos y oscuros de las cuevas

Estimation of mesospheric gravity wave momentum flux using Hybrid Doppler Interferometry

15th MST Radar WorkshopSession M6: Middle atmosphere dynamics and structureMay 31 (Wed), NIPR Auditoriu

Assessing the regional conservation status of sponges (Porifera): the case of the Aegean ecoregion

Sponges are among the less-studied benthic invertebrates as regards their extinction risk and conservation status. Herein, we evaluate the regional conservation status of sponges in the Aegean ecoregion (Eastern Mediterranean Sea), using the IUCN Red List criteria. We examined 20 sponge taxa falling into three categories: i) threatened species listed in Annex II of the Barcelona Convention, ii) bath sponge species (Annex III of the Barcelona Convention), and iii) Aegean endemics. The regional geographic range of the examined taxa was depicted on detailed distribution maps, based mostly on recent observations by the authors and literature data. When possible, population trends were estimated based on historical data, and threats were identified. The suggested regional conservation status of the examined sponge species is as follows: i) nine species were characterised as ‘Data Deficient (DD)’ due to limited available information; ii) seven species were assigned to the ‘Least Concern (LC)’ category; iii) the four harvested bath sponge species were assigned to the Endangered (EN) category, based on their population decline in the Aegean region during the past decades. The present evaluation, besides providing scientific data for the regional protection and management of sponge populations, can form a basis for wider assessment and consequent conservation of Porifera

Cultural and socio-economic impacts of Mediterranean marine protected areas

Marine protected areas (MPAs) may be important for protecting the marine environment, but they may also have substantial socio-cultural impacts about which very little is currently known, or acknowledged. In the Mediterranean, few data are available on the socio-economic consequences of MPAs. The present study reviews the existing data on MPAs in Spain, France, Italy and Greece. A general increase in tourist activities in Mediterranean MPAs is evident, as are increases in the abundances of larger fish species, although there are no data indicating yields for fisheries increase adjacent to MPAs. A large increase in the number of divers and vessels using MPAs has already had impacts on natural benthic communities as a result of diver damage, mooring and the feeding of large fish by divers. Emphasis has been given in only a few MPAs to promoting public awareness of these impacts. Although the conservation of nature should be considered the fundamental objective of MPAs, neglecting their social, cultural and economic impacts has at times led to poor local consensus, if not hostility. We believe that planning and managing MPAs should be conducted on a multidisciplinary basis. Nonetheless, no single model can be considered valid for the whole Mediterranean. The very variable characteristics of coastal areas, from those of small uninhabited islands to those of cities, require different weightings to be assigned for each factor in order to achieve a durable equilibrium and realize the original objectives of each MPA. Only with such flexibility of management will it be possible to reach a greater understanding of the MPA system and create a lasting consensus in favour of conservation, a consensus which would mean an overwhelming majority of people actively avoiding damaging nature and preventing others from doing so.This paper was realized with funds from the EU CEC DGXII–MAST III contract number: MAS3-ct97–0155

The Biodiversity of the Mediterranean Sea: Estimates, Patterns, and Threats

The Mediterranean Sea is a marine biodiversity hot spot. Here we combined an extensive literature analysis with expert opinions to update publicly available estimates of major taxa in this marine ecosystem and to revise and update several species lists. We also assessed overall spatial and temporal patterns of species diversity and identified major changes and threats. Our results listed approximately 17,000 marine species occurring in the Mediterranean Sea. However, our estimates of marine diversity are still incomplete as yet—undescribed species will be added in the future. Diversity for microbes is substantially underestimated, and the deep-sea areas and portions of the southern and eastern region are still poorly known. In addition, the invasion of alien species is a crucial factor that will continue to change the biodiversity of the Mediterranean, mainly in its eastern basin that can spread rapidly northwards and westwards due to the warming of the Mediterranean Sea. Spatial patterns showed a general decrease in biodiversity from northwestern to southeastern regions following a gradient of production, with some exceptions and caution due to gaps in our knowledge of the biota along the southern and eastern rims. Biodiversity was also generally higher in coastal areas and continental shelves, and decreases with depth. Temporal trends indicated that overexploitation and habitat loss have been the main human drivers of historical changes in biodiversity. At present, habitat loss and degradation, followed by fishing impacts, pollution, climate change, eutrophication, and the establishment of alien species are the most important threats and affect the greatest number of taxonomic groups. All these impacts are expected to grow in importance in the future, especially climate change and habitat degradation. The spatial identification of hot spots highlighted the ecological importance of most of the western Mediterranean shelves (and in particular, the Strait of Gibraltar and the adjacent Alboran Sea), western African coast, the Adriatic, and the Aegean Sea, which show high concentrations of endangered, threatened, or vulnerable species. The Levantine Basin, severely impacted by the invasion of species, is endangered as well

Suberitidae (Demospongiae, Hadromerida) from the North Aegean Sea

Sampling in the North Aegean Sea yielded nine species of the family Suberitidae, four of which, Pseudosuberites sulphureus, P. hyalinus, Suberiles ficus and S. syringella, are new for the fauna of the Eastern Mediterranean, and three more, S. carnosus, S. domuncula, and S. massa, are new records for the fauna of the Aegean Sea. For each of the nine species comments on the systematics, as well as geographical and ecological information is given. A redescription is given of the little known species Suberites massa Nardo. A review of the distribution of all Mediterranean Suberitidae is also presented, in which it is concluded that a further three species not represented in our material have been reported from the Eastern Mediterranean, viz. Laxosuberites ectyoninus, Prosuberites longispina, and P. epiphytum. Six suberitids reported from other parts of the Mediterranean so far have not been found in the Eastern Mediterranean

Hemiasterella aristoteliana n. sp. (Porifera, Hadromerida) from the Aegean Sea with a discussion on the family Hemiasterellidae

A representative of the genus Hemiasterella Carter, 1879 was found for the first time in the Mediterranean Sea during sampling in the shallow waters of the northern Aegean Sea. The new species, H. aristoteliana, is compared with Atlantic Hemiasterella elongata Topsent, 1928. The status of the family Hemiasterellidae is discussed

Resemblance of sponge assemblages from cave zones (entrance-CE, semidark-SD, dark-D) of Mediterranean subareas.

<p>For abbreviations of Mediterranean areas see <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0039873#s2" target="_blank">Methods</a>.</p