Biological response to geochemical and hydrological processes in a shallow submarine cave

The Croatian coastal karst abounds in submerged caves that host a variety of environmental conditions depending on the geomorphology, depth and submarine groundwater discharge. One example is the Y-Cave, a shallow, mostly submerged, horizontal cave on Dugi Otok Island, on the eastern Adriatic coast. This study was aimed at examining the temporal and spatial variability of the marine cave environment, including temperature, salinity, light intensity, cave morphology and hydrodynamism, along with the dissolutional effect caused by the mixing of sea and freshwater. The general distribution of organisms in the Y-Cave was positively correlated to the light gradient and reduced water circulation, thus the highest species diversity and abundance were recorded in the front part of the cave. The phylum Porifera was the most dominant group, and the poriferan species diversity in the cave ranks among the ten highest in the Mediterranean. The middle part of the cave, although completely dark, hosts an abundant population of the gastropod Homalopoma sanguineum and clusters of the gregarious brachiopod Novocrania anomala, whose presence could be connected to tidal hydrodynamics. The absence/scarcity of sessile marine organisms and pronounced corrosion marks at shallow depths inside the cave suggest a freshwater impact in the upper layers of the water column. A year long experiment with carbonate tablets revealed three different, independent ongoing processes affected by the position in the cave: bioaccumulation, dissolution and mechanical erosion. The results of long-term temperature readings also revealed water column stratification within the cave, which was not disturbed by either tidal or wave action. The shallow, partly submerged and relatively small Y-Cave is characterised by a suite of complex environmental conditions, which, together with the resulting distribution of organisms, are unique to this cave

Exploring the response of a key Mediterranean gorgonian to heat stress across biological and spatial scales

Understanding the factors and processes that shape intra-specific sensitivity to heat stress is fundamental to better predicting the vulnerability of benthic species to climate change. Here, we investigate the response of a habitat-forming Mediterranean octocoral, the red gorgonian Paramuricea clavata (Risso, 1826) to thermal stress at multiple biological and geographical scales. Samples from eleven P. clavata populations inhabiting four localities separated by hundreds to more than 1500 km of coast and with contrasting thermal histories were exposed to a critical temperature threshold (25 degrees C) in a common garden experiment in aquaria. Ten of the 11 populations lacked thermotolerance to the experimental conditions provided (25 days at 25 degrees C), with 100% or almost 100% colony mortality by the end of the experiment. Furthermore, we found no significant association between local average thermal regimes nor recent thermal history (i.e., local water temperatures in the 3 months prior to the experiment) and population thermotolerance. Overall, our results suggest that local adaptation and/or acclimation to warmer conditions have a limited role in the response of P. clavata to thermal stress. The study also confirms the sensitivity of this species to warm temperatures across its distributional range and questions its adaptive capacity under ocean warming conditions. However, important inter-individual variation in thermotolerance was found within populations, particularly those exposed to the most severe prior marine heatwaves. These observations suggest that P. clavata could harbor adaptive potential to future warming acting on standing genetic variation (i.e., divergent selection) and/or environmentally-induced phenotypic variation (i.e., intra- and/or intergenerational plasticity).European Commission SEP-210597628- FutureMARES, MCIU/AEI/FEDER RTI2018-095346-BI00, Spanish government through the `Severo Ochoa Centre of Excellence' accreditation CEX2019-000928-S , Interreg Med Programme 5216|5MED18_3.2_M23_007, 1MED15_3.2_M2_ 337, Spanish Government FPU15/05457, Fundacao para a Ciencia e a Tecnologia (FCT) LA/P/0101/2020 , DivRestore/0013/2020, Marine Conservation research group 2017 SGR 1521, postdoctoral fellowship of project HABMAR - European Maritime and Fisheries Fund of the Operational Program MAR 2020 for Portugal MAR-01.04.02-FEAMP-0018info:eu-repo/semantics/publishedVersio

Collaborative database to track Mass Mortality Events in the Mediterranean Sea

Anthropogenic climate change, and global warming in particular, has strong and increasing impacts on marine ecosystems (Poloczanska et al., 2013; Halpern et al., 2015; Smale et al., 2019). The Mediterranean Sea is considered a marine biodiversity hotspot contributing to more than 7% of world\u2019s marine biodiversity including a high percentage of endemic species (Coll et al., 2010). The Mediterranean region is a climate change hotspot, where the respective impacts of warming are very pronounced and relatively well documented (Cramer et al., 2018). One of the major impacts of sea surface temperature rise in the marine coastal ecosystems is the occurrence of mass mortality events (MMEs). The first evidences of this phenomenon dated from the first half of \u201980 years affecting the Western Mediterranean and the Aegean Sea (Harmelin, 1984; Bavestrello and Boero, 1986; Gaino and Pronzato, 1989; Voultsiadou et al., 2011). The most impressive phenomenon happened in 1999 when an unprecedented large scale MME impacted populations of more than 30 species from different phyla along the French and Italian coasts (Cerrano et al., 2000; Perez et al., 2000). Following this event, several other large scale MMEs have been reported, along with numerous other minor ones, which are usually more restricted in geographic extend and/or number of affected species (Garrabou et al., 2009; Rivetti et al., 2014; Marb\ue0 et al., 2015; Rubio-Portillo et al., 2016, authors\u2019 personal observations). These events have generally been associated with strong and recurrent marine heat waves (Crisci et al., 2011; Kersting et al., 2013; Turicchia et al., 2018; Bensoussan et al., 2019) which are becoming more frequent globally (Smale et al., 2019). Both field observations and future projections using Regional Coupled Models (Adloff et al., 2015; Darmaraki et al., 2019) show the increase in Mediterranean sea surface temperature, with more frequent occurrence of extreme ocean warming events. As a result, new MMEs are expected during the coming years. To date, despite the efforts, neither updated nor comprehensive information can support scientific analysis of mortality events at a Mediterranean regional scale. Such information is vital to guide management and conservation strategies that can then inform adaptive management schemes that aim to face the impacts of climate change

European Red List of Habitats Part 1. Marine habitats

The European Red List of Habitats provides an overview of the risk of collapse (degree of endangerment) of marine, terrestrial and freshwater habitats in the European Union (EU28) and adjacent regions (EU28+), based on a consistent set of categories and criteria, and detailed data and expert knowledge from involved countries1. A total of 257 benthic marine habitat types were assessed. In total, 19% (EU28) and 18% (EU28+) of the evaluated habitats were assessed as threatened in categories Critically Endangered, Endangered and Vulnerable. An additional 12% were Near Threatened in the EU28 and 11% in the EU28+. These figures are approximately doubled if Data Deficient habitats are excluded. The percentage of threatened habitat types differs across the regional seas. The highest proportion of threatened habitats in the EU28 was found in the Mediterranean Sea (32%), followed by the North-East Atlantic (23%), the Black Sea (13%) and then the Baltic Sea (8%). There was a similar pattern in the EU28+. The most frequently cited pressures and threats were similar across the four regional seas: pollution (eutrophication), biological resource use other than agriculture or forestry (mainly fishing but also aquaculture), natural system modifications (e.g. dredging and sea defence works), urbanisation and climate change. Even for habitats where the assessment outcome was Data Deficient, the Red List assessment process has resulted in the compilation of a substantial body of useful information to support the conservation of marine habitats

Molecular Phylogeny of the Astrophorida (Porifera, Demospongiaep) Reveals an Unexpected High Level of Spicule Homoplasy

Background: The Astrophorida (Porifera, Demospongiae(rho)) is geographically and bathymetrically widely distributed. Systema Porifera currently includes five families in this order: Ancorinidae, Calthropellidae, Geodiidae, Pachastrellidae and Thrombidae. To date, molecular phylogenetic studies including Astrophorida species are scarce and offer limited sampling. Phylogenetic relationships within this order are therefore for the most part unknown and hypotheses based on morphology largely untested. Astrophorida taxa have very diverse spicule sets that make them a model of choice to investigate spicule evolution. Methodology/Principal Findings: With a sampling of 153 specimens (9 families, 29 genera, 89 species) covering the deep- and shallow-waters worldwide, this work presents the first comprehensive molecular phylogeny of the Astrophorida, using a cytochrome c oxidase subunit I (COI) gene partial sequence and the 59 end terminal part of the 28S rDNA gene (C1-D2 domains). The resulting tree suggested that i) the Astrophorida included some lithistid families and some Alectonidae species, ii) the sub-orders Euastrophorida and Streptosclerophorida were both polyphyletic, iii) the Geodiidae, the Ancorinidae and the Pachastrellidae were not monophyletic, iv) the Calthropellidae was part of the Geodiidae clade (Calthropella at least), and finally that v) many genera were polyphyletic (Ecionemia, Erylus, Poecillastra, Penares, Rhabdastrella, Stelletta and Vulcanella). Conclusion: The Astrophorida is a larger order than previously considered, comprising ca. 820 species. Based on these results, we propose new classifications for the Astrophorida using both the classical rank-based nomenclature (i.e., Linnaean classification) and the phylogenetic nomenclature following the PhyloCode, independent of taxonomic rank. A key to the Astrophorida families, sub-families and genera incertae sedis is also included. Incongruences between our molecular tree and the current classification can be explained by the banality of convergent evolution and secondary loss in spicule evolution. These processes have taken place many times, in all the major clades, for megascleres and microscleres

Global Diversity of Sponges (Porifera)

With the completion of a single unified classification, the Systema Porifera (SP) and subsequent development of an online species database, the World Porifera Database (WPD), we are now equipped to provide a first comprehensive picture of the global biodiversity of the Porifera. An introductory overview of the four classes of the Porifera is followed by a description of the structure of our main source of data for this paper, the WPD. From this we extracted numbers of all ‘known’ sponges to date: the number of valid Recent sponges is established at 8,553, with the vast majority, 83%, belonging to the class Demospongiae. We also mapped for the first time the species richness of a comprehensive set of marine ecoregions of the world, data also extracted from the WPD. Perhaps not surprisingly, these distributions appear to show a strong bias towards collection and taxonomy efforts. Only when species richness is accumulated into large marine realms does a pattern emerge that is also recognized in many other marine animal groups: high numbers in tropical regions, lesser numbers in the colder parts of the world oceans. Preliminary similarity analysis of a matrix of species and marine ecoregions extracted from the WPD failed to yield a consistent hierarchical pattern of ecoregions into marine provinces. Global sponge diversity information is mostly generated in regional projects and resources: results obtained demonstrate that regional approaches to analytical biogeography are at present more likely to achieve insights into the biogeographic history of sponges than a global perspective, which appears currently too ambitious. We also review information on invasive sponges that might well have some influence on distribution patterns of the future

Pour la Paix en Europe. Institutions et société civile dans l’entre-deux-guerres - For Peace in Europe. Institutions and Civil Society between the World Wars

Il processo di unione europea vede oggi una battuta di arresto sul piano politico-istituzionale, nonostante le tappe decisive realizzate in questo secondo dopoguerra. Restano cioè da affrontare temi e problemi che già animarono il dibattito tra i pionieri dell’europeismo tra le due guerre mondiali. Se allora il complesso delle loro proposte rimase inascoltato, con un esito distruttivo per la pace e l’Europa, una tale preziosa eredità ideale ha consentito una continuità e un germoglio successivi. Questo libro nasce dalla collaborazione di ventisei studiosi europei, con lo scopo di presentare una serie di idee, iniziative, programmi, che tra le due guerre mondiali intesero promuovere il mantenimento di un ordine internazionale pacificato, muovendo dal nevralgico contesto europeo. Emerge così un humus significativo e trasversale, contrapposto alle tendenze inesorabilmente prevalenti nella politica e nelle istituzioni, ma anche nella società civile. I suoi animatori operarono nelle organizzazioni internazionali, nei partiti, movimenti, associazioni di stampo non solo politico, così come nella storiografia, nella letteratura, nel teatro, nel cinema, nello sport, segnalando gli elementi per una rinascita della convivenza pacifica sul piano europeo e internazionale. Le processus d’union européenne voit aujourd’hui un point d’arrêt sur le plan politique et institutionnel, malgré les étapes décisives réalisées durant la période de l’après-guerre. Il reste en effet à affronter des thèmes et des problèmes qui, pendant l’entre-deux-guerres, animèrent le débat entre les pionniers de l’européanisme. Si, à l’époque, leurs propositions restèrent sans suite, ayant une issue destructrice pour la paix et l’Europe, cet héritage idéal si précieux a permis une continuité et de germer par la suite. Ayant pour but de présenter une série d’idées, d’initiatives, de programmes, ce livre est le fruit de la collaboration de vingt-six experts européens, qui entre les deux guerres entendirent promouvoir le maintien d’un ordre international pacifié, partant du névralgique contexte européen. Il en ressort ainsi un humus significatif et transversal, opposé aux tendances inexorablement prédominantes dans la politique et les institutions, mais aussi dans la société civile. Ses animateurs oeuvrèrent dans les organisations internationales, les partis, les mouvements, les associations de type non seulement politique, de même que dans l’historiographie, la littérature, le théâtre, le cinéma, le sport, signalant les éléments en vue d’une renaissance de la cohabitation pacifique sur le plan européen et international. Despite the decisive steps forward made since the Second World War, the process of European unification has come to a standstill at a political and institutional level. Issues and problems which were already the subject of debate among the pioneers of Europeanism between the two wars have still to be addressed. Although at the time their proposal as a whole went unheeded, with destructive consequences for peace and for Europe, this valuable legacy of ideals has nevertheless guaranteed a continuity and a subsequent blossoming. The purpose of this book, the result of the collaboration of twenty six European scholars, is to examine a series of ideas, initiatives and programmes which, between the two World Wars, aimed to promote the maintenance of a pacified international order, starting from the crucial European context. What emerges is a significant and transversal humus, that countered the inexorably prevailing tendencies in politics and institutions, and even in society. Its exponents operated in international organisations, in parties, and in movements and associations not necessarily of a political stamp, as well as in historiography, literature, theatre, cinema and sport, laying the foundations for a rebirth of peaceful co-existence at European and international level