Response of the meiofaunal annelid Saccocirrus pussicus (Saccocirridae) to sandy beach morphodynamics

Australia is increasingly recognised as a global hotspot for sponge biodiversity, but there is a knowledge gap about sponge communities in northern Australia, including those in Commonwealth Marine Reserves. We aim to quantify sponge biodiversity of the eastern Joseph Bonaparte Gulf and adjacent Van Diemen Rise (VDR) and to examine spatial and environmental patterns in community structure. Sponges were collected with a benthic sled from 65 sites encompassing five geomorphic features (bank, terrace, ridge, plain, and valley), study area (as a proxy for distance offshore) and three environmental variables (depth, substrate hardness, and slope). A total of 283 species were collected, representing four classes, 53 families and at least 117 genera. Sponge richness and biomass were related to those of other taxa. Sponge diversity was generally highest further offshore and on raised geomorphic features, particularly banks. Sponge assemblages on the same bank were more similar than those from different banks, although full interpretation of patterns is limited by the relatively low sampling effort. The current study will help facilitate integrated marine management by providing a baseline species inventory, supporting the VDR’s carbonate banks as a key ecological feature, and highlighting the importance of sponges as habitat providers and potential biological surrogates for monitoring.     

Quantifying Fish Assemblages in Large,Offshore Marine Protected Areas: An Australian Case Study

As the number of marine protected areas (MPAs) increases globally, so does the need to assess if MPAs are meeting their management goals. Integral to this assessment is usually a long-term biological monitoring program, which can be difficult to develop for large and remote areas that have little available fine-scale habitat and biological data. This is the situation for many MPAs within the newly declared Australian Commonwealth Marine Reserve (CMR) network which covers approximately 3.1 million km² of continental shelf, slope, and abyssal habitat, much of which is remote and difficult to access. A detailed inventory of the species, types of assemblages present and their spatial distribution within individual MPAs is required prior to developing monitoring programs to measure the impact of management strategies. Here we use a spatially-balanced survey design and non-extractive baited video observations to quantitatively document the fish assemblages within the continental shelf area (a multiple use zone, IUCN VI) of the Flinders Marine Reserve, within the Southeast marine region. We identified distinct demersal fish assemblages, quantified assemblage relationships with environmental gradients (primarily depth and habitat type), and described their spatial distribution across a variety of reef and sediment habitats. Baited videos recorded a range of species from multiple trophic levels, including species of commercial and recreational interest. The majority of species, whilst found commonly along the southern or south-eastern coasts of Australia, are endemic to Australia, highlighting the global significance of this region. Species richness was greater on habitats containing some reef and declined with increasing depth. The trophic breath of species in assemblages was also greater in shallow waters. We discuss the utility of our approach for establishing inventories when little prior knowledge is available and how such an approach may inform future monitoring efforts within the CMR network.     

Marine caves of the Mediterranean Sea: a sponge biodiversity reservoir within a biodiversity hotspot

Marine caves are widely acknowledged for their unique biodiversity and constitute a typical feature of the Mediterranean coastline. Herein an attempt was made to evaluate the ecological significance of this particular ecosystem in the Mediterranean Sea, which is considered a biodiversity hotspot. This was accomplished by using Porifera, which dominate the rocky sublittoral substrata, as a reference group in a meta-analytical approach, combining primary research data from the Aegean Sea (eastern Mediterranean) with data derived from the literature. In total 311 species from all poriferan classes were recorded, representing 45.7% of the Mediterranean Porifera. Demospongiae and Homoscleromorpha are highly represented in marine caves at the family (88%), generic (70%), and species level (47.5%), the latter being the most favored group along with Dictyoceratida and Lithistida. Several rare and cave-exclusive species were reported from only one or few caves, indicating the fragmentation and peculiarity of this unique ecosystem. Species richness and phylogenetic diversity varied among Mediterranean areas; the former was positively correlated with research effort, being higher in the northern Mediterranean, while the latter was generally higher in caves than in the overall sponge assemblages of each area. Resemblance analysis among areas revealed that cavernicolous sponge assemblages followed a pattern quite similar to that of the overall Mediterranean assemblages. The same pattern was exhibited by the zoogeographic affinities of cave sponges: species with Atlanto-Mediterranean distribution and Mediterranean endemics prevailed (more than 40% each), 70% of them having warm-water affinities, since most caves were studied in shallow waters. According to our findings, Mediterranean marine caves appear to be important sponge biodiversity reservoirs of high representativeness and great scientific interest, deserving further detailed study and protection.     

Rapid assessment of invertebrate biodiversity on rocky shores: where there’s a whelk there’s a way

The lack of species inventory data for most marine habitats currently hampers the objective management of marine biodiversity. There is thus a clear need to find reliable indicator taxa that can be targeted in marine conservation studies, providing cost-effective data for planning and monitoring. Using the rocky shores of the Solitary Islands Marine Park, NSW, Australia, as a model, I evaluated macroinvertebrates and determined which taxa (i) best reflected ecological patterns of the broader intertidal community; and (ii) were able to accurately predict species richness of assemblages at the headland scale. Both molluscs and crustaceans showed high levels of correlation with overall species richness. However, molluscs, and in particular prosobranchs, most closely reflected patterns in the community data and provided the most accurate predictions of species richness at the scale of the headland. The potential time savings of using molluscs in rapid assessments are considerable and relate to reductions in field time (by up to 40%) as well as the reduced need to invest time developing extensive taxonomic knowledge of other invertebrate groups. Molluscs are widespread and easily sampled, with stable taxonomy and well-known ecology relative to other marine invertebrate taxa. Their use as surrogates of biodiversity shows great potential for future marine conservation studies.     

Objective selection of surrogate families to describe reef fish assemblages in a subtropical marine park

Effective representation of biodiversity in a marine park can be limited by lack of sampling at a suitable scale due to various methodological, logistical and taxonomic constraints. Surrogates that describe key components of biodiversity can benefit management planning and assist evaluation of zoning arrangements by improving efficiency and effectiveness of sampling. Reef fish are considered an important component of biodiversity in the Solitary Islands Marine Park (SIMP), New South Wales, Australia. Fish assemblages were surveyed using 30-min timed counts at 68 sites spread across the extent of shallow reef in the SIMP. The overall assemblage was compared with various subsets of taxa using the RELATE procedure in PRIMER to determine useful surrogates. Two families, Labridae and Pomacentridae, showed a high concordance with overall patterns and the highest correlation in estimating species richness by site. These families were the two most speciose (43, 32 species, respectively) comprising 30% of the species richness out of 66 families and 254 species. Surveying a subset of species that includes these two families has utility for marine park management in the SIMP, including evaluating the influence of ‘no take’ zones on assemblage patterns and systematic planning for biodiversity representation.     

A Hierarchical Classification of Benthic Biodiversity and Assessment of Protected Areas in the Southern Ocean

An international effort is underway to establish a representative system of marine protected areas (MPAs) in the Southern Ocean to help provide for the long-term conservation of marine biodiversity in the region. Important to this undertaking is knowledge of the distribution of benthic assemblages. Here, our aim is to identify the areas where benthic marine assemblages are likely to differ from each other in the Southern Ocean including near-shore Antarctica. We achieve this by using a hierarchical spatial classification of ecoregions, bathomes and environmental types. Ecoregions are defined according to available data on biogeographic patterns and environmental drivers on dispersal. Bathomes are identified according to depth strata defined by species distributions. Environmental types are uniquely classified according to the geomorphic features found within the bathomes in each ecoregion. We identified 23 ecoregions and nine bathomes. From a set of 28 types of geomorphic features of the seabed, 562 unique environmental types were classified for the Southern Ocean. We applied the environmental types as surrogates of different assemblages of biodiversity to assess the representativeness of existing MPAs. We found that 12 ecoregions are not represented in MPAs and that no ecoregion has their full range of environmental types represented in MPAs. Current MPA planning processes, if implemented, will substantially increase the representation of environmental types particularly within 8 ecoregions. To meet internationally agreed conservation goals, additional MPAs will be needed. To assist with this process, we identified 107 spatially restricted environmental types, which should be considered for inclusion in future MPAs. Detailed supplementary data including a spatial dataset are provided.     

A sponge diversity centre within a marine ‘island’

The exposed and gulf-stream warmed south-west coast of Ireland has a Lusitanean fauna composed of elements of the colder waters to the north and east, and others from the warmer Mediterranean Sea. Lough Hyne, a small marine body, is unusual on this coast in being very sheltered, but also in being characterised by many different niches within a small space (1 km²). Sponges are particularly abundant, morphologically varied and more than 100 species have been described. Species diversity was measured at 6 m intervals on vertical and inclined profiles (to a maximum of 30 m) at six sites, spanning a range of flow rate and sedimentation regimes. Diversity, richness, evenness and density varied significantly with both flow regime and depth, but was much lower on the surrounding Atlantic coast. Four different sponge communities were differentiated on the basis of sponge species assemblages which correlated with different environmental conditions. At sites of turbulent and fast flow conditions, sponge diversity and richness were lowest, with the highest values being found at the sites of moderate and high sedimentation. Significant differences were observed in all four ecological variables with respect to substratum angle with the exception of the site experiencing the most turbulent flow conditions. Lough Hyne was found to possess the second highest sponge species diversity (H=3.626) and richness (77 species) of all available figures from temperate, polar and tropical areas (of similar sized sampling area). The uniqueness, diversity and species composition of the sponge community at this location suggests Lough Hyne is, biologically, a marine island within the island of Ireland.     

Current and future patterns of global marine mammal biodiversity

Quantifying the spatial distribution of taxa is an important prerequisite for the preservation of biodiversity, and can provide a baseline against which to measure the impacts of climate change. Here we analyse patterns of marine mammal species richness based on predictions of global distributional ranges for 115 species, including all extant pinnipeds and cetaceans. We used an environmental suitability model specifically designed to address the paucity of distributional data for many marine mammal species. We generated richness patterns by overlaying predicted distributions for all species; these were then validated against sightings data from dedicated long-term surveys in the Eastern Tropical Pacific, the Northeast Atlantic and the Southern Ocean. Model outputs correlated well with empirically observed patterns of biodiversity in all three survey regions. Marine mammal richness was predicted to be highest in temperate waters of both hemispheres with distinct hotspots around New Zealand, Japan, Baja California, the Galapagos Islands, the Southeast Pacific, and the Southern Ocean. We then applied our model to explore potential changes in biodiversity under future perturbations of environmental conditions. Forward projections of biodiversity using an intermediate Intergovernmental Panel for Climate Change (IPCC) temperature scenario predicted that projected ocean warming and changes in sea ice cover until 2050 may have moderate effects on the spatial patterns of marine mammal richness. Increases in cetacean richness were predicted above 40° latitude in both hemispheres, while decreases in both pinniped and cetacean richness were expected at lower latitudes. Our results show how species distribution models can be applied to explore broad patterns of marine biodiversity worldwide for taxa for which limited distributional data are available.     

Testing the suitability of a morphological monitoring approach for identifying temporal variability in a temperate sponge assemblage

Sponges are a dominant component of benthic assemblages in hard substratum environments across the world, but despite the importance of sponges, they are generally poorly represented in most marine monitoring programmes. There is considerable need to develop effective monitoring tools to monitor changes in sponge assemblages. Morphological monitoring has been proposed as a suitable method to monitor sponges and while morphological monitoring has already taken place at Skomer Marine Reserve (MNR), Wales, here we investigate whether species level and morphological level data sets are correlated with respect to temporal variation. Furthermore, we examine the environmental factors that correlate with the patterns of temporal variability. Both species and morphological data sets revealed significant seasonal changes and spatial variation in sponge assemblages; these data sets were highly correlated and explained by a number of environmental factors. We conclude that morphological monitoring of sponge assemblages may represents a cost-effective method for assessing temporal and spatial variation in sponges, where full species level monitoring is not possible, as patterns identified from morphological data were a suitable surrogate of species-level data.     

Fish Assemblages Survey Technique (Fast) in Tunisian marine waters (Central Mediterranean)

Following the heightened damage of marine ecosystems, Marine Protected Areas (MPAs) have been created for the protection and the conservation of species and habitats. However, their implementation requires accurate data availability used by decision makers to enable their boundaries and zoning. Thus, for this purpose of management, a new method of fish assemblages monitoring (FAST—Fish Assemblages Survey Technique) has been tested in Tunisian marine waters. FAST survey was applied between 2011 and 2012 in three areas with various degrees of geomorphological features and human pressures; the future Marine Protected Area of Cap Serrat–Cap Negro and two coastal areas of Hammamet and Bizerte. The depths of the surveyed 11 stations are between 0 and 20 m. The FAST index is calculated seasonally for targeted species according to their presence / absence, and depending on two size classes. In terms of diversity and species richness, differences between sites were observed and results show that FAST method appears to be relevant, easy to implement and accurately reflects the environmental status of the study site. The advantages and shortcomings of this method were discussed.     

Coastal sponge communities of the West Indian Ocean: taxonomic affinities, richness and diversity

Sponges assemblages were sampled in four coastal study regions (Malindi, Kenya; Quirimba Archipelago, northern Mozambique; Inhaca Island, Southern Mozambique and Anakao, Madagascar) in the west Indian Ocean. Sponge species were counted in multiple 0.5 m² quadrats at depths of between 0 and 20 m at a number of sites within localities within each region. Despite the relatively small areas sampled, sponge samples comprised a total of 130 species and 70 genera of the classes Demospongiae and Calcarea. Sponges are clearly a major taxon in these regions in terms of numbers of species, percentage cover or biomass, although their ecology in the west Indian Ocean is virtually unknown. Nearly half of the genera, e.g. Iotrochota, found were species with a so‐called Tethyan distribution. Most of the other genera were cosmopolitan, e.g. Clathria, but some were cold water (Coelosphaera), Indo‐Australian (Ianthella) or circum‐African (Crambe). Many of the species encountered in the present study occurred in at least two study regions, many in more and could occupy large areas of substratum. Some of these, e.g. Xestospongia exigua, are commonly found throughout the Indo‐west Pacific region where they also occupy much space. The endemicity of the shallow water sponge faunas in East Africa (20–25%) seem to be high within the Indo‐Pacific realm but are lower than northern Papua New Guinea. The tropical regions (Kenya and Northern Mozambique) were more speciose than subtropical regions (southern Mozambique and Madagascar) but not significantly more diverse (Shannon H′). Although latitude was not a major influence on sponge community patterns, hard substratum assemblages did form a cline from the tropics to Southern Mozambique, linked by Madagascar. Substratum nature (habitat) was most important in influencing the suite and number of species present. Sponge assemblages of soft substrata were much more dissimilar, both within and between habitats, than those on hard substrata. There was a predictable variability in species richness between hard substratum habitats: coral reefs being speciose and caves being less so. Our findings showed that both patterns and influences on species richness may be decoupled from those influencing diversity. In our data species richness, but not diversity, showed striking regional and bathymetric trends. In addition, sponge species richness mainly split at coral reef vs. non‐reef habitats, whilst diversity divided principally into assemblages on hard and soft substrata. We consider this dichotomy of findings between species richness and diversity values to be important, as these are two principal measures used for the interpretation of biodiversity.     

Biodiversity, molecular ecology and phylogeography of marine sponges: patterns, implications and outlooks

Marine sponges are an ecologically important and highly diversecomponent of marine benthic communities, found in all the world'soceans, at all depths. Although their commercial potential andevolutionary importance is increasingly recognized, many pivotalaspects of their basic biology remain enigmatic. Knowledge ofhistorical biogeographic affinities and biodiversity patternsis rudimentary, and there are still few data about genetic variationamong sponge populations and spatial patterns of this variation.Biodiversity analyses of tropical Australasian sponges revealedspatial trends not universally reflected in the distributionsof other marine phyla within the Indo-West Pacific region. Atsmaller spatial scales sponges frequently form heterogeneous,spatially patchy assemblages, with some empirical evidence suggestingthat environmental variables such as light and/or turbiditystrongly contribute to local distributions. There are no apparentlatitudinal diversity gradients at larger spatial scales butstochastic processes, such as changing current patterns, thepresence or absence of major carbonate platforms and historicalbiogeography, may determine modern day distributions. Studieson Caribbean oceanic reefs have revealed similar patterns, onlyweakly correlated with environmental factors. However, severalquestions remain where molecular approaches promise great potential,e.g., concerning connectivity and biogeographic relationships.Studies to date have helped to reveal that sponge populationsare genetically highly structured and that historical processesmight play an important role in determining such structure.Increasingly sophisticated molecular tools are now being applied,with results contributing significantly to a better understandingof poriferan microevolutionary processes and molecular ecology.     

Synthesis of Knowledge on Marine Biodiversity in European Seas: From Census to Sustainable Management

The recently completed European Census of Marine Life, conducted within the framework of the global Census of Marine Life programme (2000–2010), markedly enhanced our understanding of marine biodiversity in European Seas, its importance within ecological systems, and the implications for human use. Here we undertake a synthesis of present knowledge of biodiversity in European Seas and identify remaining challenges that prevent sustainable management of marine biodiversity in one of the most exploited continents of the globe. Our analysis demonstrates that changes in faunal standing stock with depth depends on the size of the fauna, with macrofaunal abundance only declining with increasing water depth below 1000 m, whilst there was no obvious decrease in meiofauna with increasing depth. Species richness was highly variable for both deep water macro- and meio- fauna along latitudinal and longitudinal gradients. Nematode biodiversity decreased from the Atlantic into the Mediterranean whilst latitudinal related biodiversity patterns were similar for both faunal groups investigated, suggesting that the same environmental drivers were influencing the fauna. While climate change and habitat degradation are the most frequently implicated stressors affecting biodiversity throughout European Seas, quantitative understanding, both at individual and cumulative/synergistic level, of their influences are often lacking. Full identification and quantification of species, in even a single marine habitat, remains a distant goal, as we lack integrated data-sets to quantify these. While the importance of safeguarding marine biodiversity is recognised by policy makers, the lack of advanced understanding of species diversity and of a full survey of any single habitat raises huge challenges in quantifying change, and facilitating/prioritising habitat/ecosystem protection. Our study highlights a pressing requirement for more complete biodiversity surveys to be undertaken within contrasting habitats, together with investigations in biodiversity-ecosystem functioning links and identification of separate and synergistic/cumulative human-induced impacts on biodiversity.     

Biogeographical patterns of algal communities in the Mediterranean Sea: Cystoseira crinita‐dominated assemblages as a case study

Aim The aim of this study was to describe the composition, community structure and biogeographical variation of subtidal algal assemblages dominated by the brown alga Cystoseira crinita across the Mediterranean Sea. Location The Mediterranean coast, from Spain (1°25′ E) to Turkey (30°26′ E). Methods Data on the species composition and structure of assemblages dominated by the species C. crinita were collected from 101 sites in nine regions across the Mediterranean Sea. Multivariate and univariate statistical tools were used to investigate patterns of variation in the composition of the assemblages among sites and regions, and to compare these with previously defined biogeographical regions. Linear regressions of species richness versus longitude and versus latitude were also carried out to test previously formulated hypotheses of biodiversity gradients in the Mediterranean Sea. Results The main features characterizing C. crinita‐dominated assemblages across the Mediterranean included a similar total cover of species, a similar cover of C. crinita, and consistency in the presence of the epiphyte Haliptilon virgatum. Biogeographical variation was detected as shifts in relative abundances of species among regions, partly coinciding with previously described biogeographical sectors. A significant positive correlation was found between species richness and latitude, while no significant correlation was detected between species richness and longitude. Main conclusions The patterns of variation in community structure detected among the studied regions reflected their geographical positions quite well. However, latitude seemed to contribute more to the explanation of biological patterns of diversity than did geographical distances or boundaries, which classically have been used to delimit biogeographical sectors. Moreover, the positive correlation between species richness and latitude reinforced the idea that latitude, and possibly temperature as a related environmental factor, plays a primary role in structuring biogeographical patterns in the Mediterranean Sea. The lack of correlation between species richness and longitude contradicts the notion that there is a decrease in species richness from west to east in the Mediterranean, following the direction of species colonization from the Atlantic.     

Protected and threatened components of fish biodiversity in the Mediterranean sea

The Mediterranean Sea (0.82% of the global oceanic surface) holds 4%-18% of all known marine species (~17,000), with a high proportion of endemism [1, 2]. This exceptional biodiversity is under severe threats [1] but benefits from a system of 100 marine protected areas (MPAs). Surprisingly, the spatial congruence of fish biodiversity hot spots with this MPA system and the areas of high fishing pressure has not been assessed. Moreover, evolutionary and functional breadth of species assemblages [3] has been largely overlooked in marine systems. Here we adopted a multifaceted approach to biodiversity by considering the species richness of total, endemic, and threatened coastal fish assemblages as well as their functional and phylogenetic diversity. We show that these fish biodiversity components are spatially mismatched. The MPA system covers a small surface of the Mediterranean (0.4%) and is spatially congruent with the hot spots of all taxonomic components of fish diversity. However, it misses hot spots of functional and phylogenetic diversity. In addition, hot spots of endemic species richness and phylogenetic diversity are spatially congruent with hot spots of fishery impact. Our results highlight that future conservation strategies and assessment efficiency of current reserve systems will need to be revisited after deconstructing the different components of biodiversity.     

The shelled gastropods of the Solitary Islands Marine Park,northern New South Wales,Australia

ABSTRACT

Away from the major population centres, the biodiversity of Australia's shallow coastal marine waters is poorly known. The Tweed-Moreton Bioregion, covering northern New South Wales and south-east Queensland, is both a focus of marine conservation (with three marine parks), and research efforts to predict the effects of climate change through species range extensions and shifts in community composition. Here we provide the first comprehensive list of shallow-water (<30?m) shelled, gastropod macro-molluscs (>5?mm) from the Solitary Islands Marine Park, compiled from a range of sources, including field collections over a 30-year period to 2017. The Cypraeidae (50 spp.), Muricidae (47 spp.) and Conidae (32 spp.) were the most speciose families, accounting for 26% of the total inventory of 500 species from 77 families. A total of 143 species are recorded at their southern limit of distribution on Australia's east coast, most being rare, tropically affiliated taxa found at offshore island sites that receive more frequent contact with the southward-flowing East Australian Current. The inventory confirms the high biodiversity of the Solitary Islands region and the importance of ongoing conservation management.     

Species richness of motile cryptofauna across a gradient of reef framework erosion

Coral reef ecosystems contain exceptionally high concentrations of marine biodiversity, potentially encompassing millions of species. Similar to tropical rainforests and their insects, the majority of reef animal species are small and cryptic, living in the cracks and crevices of structural taxa (trees and corals). Although the cryptofauna make up the majority of a reef??s metazoan biodiversity, we know little about their basic ecology. We sampled motile cryptofaunal communities from both live corals and dead carbonate reef framework across a gradient of increasing erosion on a reef in Pacific Panamá. A total of 289 Operational Taxonomic Units (OTUs) from six phyla were identified. We used species-accumulation models fitted to individual- and sample-based rarefaction curves, as well as seven nonparametric richness estimators to estimate species richness among the different framework types. All procedures predicted the same trends in species richness across the differing framework types. Estimated species richness was higher in dead framework (261?C370 OTUs) than in live coral substrates (112?C219 OTUs). Surprisingly, richness increased as framework structure was eroded: coral rubble contained the greatest number of species (227?C320 OTUs) and the lowest estimated richness of 47?C115 OTUs was found in the zone where the reef framework had the greatest vertical relief. This contradicts the paradigm that abundant live coral indicates the apex of reef diversity.     

Fungal assemblages associated with sponges of the southern coast of Sakhalin Island

This paper examines the biodiversity of fungi associated with six species of sponges from the southern coast of Sakhalin Island. The species richness of fungal assemblages is represented by 78 species, mainly Anamorphic fungi. The diversity and numbers of fungi depend on the species of sponge, which is due to the rigidity of the skeleton and the morphological characteristics of the sponges.     

Effect of disturbance on assemblages: an example using porifera

Extensive sponge assemblages are found in a number of habitats at Lough Hyne Marine Nature Reserve. These habitats are unusual in experiencing a range of environmental conditions, even though they are only separated by small geographic distances (1-500 m), reducing the possibility of confounding effects between study sites (e.g., silica concentrations and temperature). Sponge assemblages were examined on ephemeral (rocks), stable (cliffs), and artificial (slate panels) hard substrata from high- and low-energy environments that were used to represent two measures of disturbance (flow rate and habitat stability). Sponge assemblages varied considerably between habitat types such that only 26% (25 species) of species reported were common to both rock and cliff habitats. Seven species (of a total of 96 species) were found in the least-developed assemblages (slate panels) and were common to all habitats. Sponge assemblages on rocks and panels varied little between high- and low-energy environments, whereas assemblages inhabiting cliffs varied considerably. Assemblage composition was visualized using Bray-Curtis similarity analysis and Multi-Dimensional Scaling, which enabled differences and similarities between sponge assemblages to be visualized. Cliffs from high- and low-energy sites had different assemblage compositions compared to large rocks, small rocks, and panels, all of which had similar assemblages irrespective of environmental conditions. Differences in assemblages were partially attributed to sponge morphology (shape), as certain morphologies (e.g., arborescent species) were excluded from 2-D rock habitats. Other mechanisms were also considered responsible for the sponge assemblages associated with different habitats.     

Projected impacts of climate warming on the functional and phylogenetic components of coastal Mediterranean fish biodiversity

Climate warming affects biodiversity distribution across all ecosystems. However, beyond changes in species richness, impacts on other biodiversity components are still overlooked, particularly in the marine realm. Here we forecasted the potential effect of climate warming on the phylogenetic and functional components of coastal Mediterranean fish biodiversity. To do so, we used species distribution models to project the potential distribution of 230 coastal fish species by the end of the 21st century based on the IPCC A2 scenario implemented with the Mediterranean climatic model NEMOMED8. From these projections, we assessed the changes in phylogenetic (PD) and functional diversity (FD) of fish assemblages at multiple spatial scales using a dated molecular phylogeny and an extensive functional trait database. At the scale of the entire Mediterranean Sea, the projected extinctions of 40 coastal fish species would lead to a concomitant erosion of PD and FD (13.6 and 3%, respectively). However, a null model revealed that species loss at this scale would not lead to a disproportionate erosion of PD and FD. Similar results were found when considering fish assemblages at the grid cell scale. Indeed, at this scale, the projected changes in species richness would lead to unexpected losses of PD and FD for localized and small areas only. A disproportionate erosion of PD under climate warming was only forecasted when analysing fish assemblages at an intermediate spatial scale, namely the Mediterranean marine ecoregions. Overall, our results emphasize the importance of considering multiple spatial scales when assessing potential impacts of climate warming on the multiple components marine biodiversity.