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Aim To characterize the species richness, endemism and community structure of benthic macro-/megafauna in the deep-sea chemosynthetic ecosystems around the Japanese archipelago and determine the conservation priority for deep-sea chemosynthetic habitats. Location Twenty-seven methane seeps from the Kuril-Japan Trench, Nankai Trough, Ryukyu Trench and Sagami Bay as well as 15 hydrothermal vents from the Izu-Bonin Arc and Okinawa Trough around the Japanese archipelago. Methods Species richness and the number of endemic species from 42 vents and seeps were examined using the distributional data of 155 mollusc, annelid and arthropod species. Multivariate analyses were performed to identify groups of sites with similar assemblage composition. Complementarity analysis was performed to determine the minimum number of sites required to conserve at least one population of all species for all 42 sites and for groups of sites detected by the multivariate analyses. Results The species richness of the deep-sea chemosynthetic sites around the Japanese archipelago was higher in the Okinawa Trough and Sagami Bay where higher methane concentrations were observed. Eight distinct biogeographic regions were detected at the community level, and the community structure was classified according to the geological variables of depth and latitude. Complementarity analysis for all 42 sites indicated 21 sites for conservation, while that for each distinct biogeographic region indicated 30 sites for conservation. Main conclusions As unique communities exist in each geographically isolated region around the Japanese archipelago, priority areas should be identified for each type of bioregion for effective conservation. At least 30 (17 seeps and 13 vents) of 42 sites should be conserved to avoid the extinction of the local populations of deep-sea chemosynthetic macro-/megabenthos. [ABSTRACT FROM AUTHOR]

Aim We provide a global assessment of the current legal direct take of marine turtles, including the scale and species breakdown at country level, and investigate the significance of legal take to marine turtle populations within the wider context of global threats. Location World-wide. Methods We undertook a comprehensive review of the literature (> 500 publications) and contacted over 150 in-country experts to collate data for countries that permit the legal take of marine turtles (as of 1 January 2013). Current annual take for each country and species was estimated, and estimates were generated for the 1980s, 1990s and 2000s. Results Currently, 42 countries and territories permit direct take of turtles and collectively take in excess of 42,000 turtles per year, the majority of which (> 80%) are green turtles Chelonia mydas (Linnaeus 1758). Ten countries account for more than 90% of legal take each year with Papua New Guinea (36.1%) and Nicaragua (22.3%) accounting for more than half of the total global take. Since 1980, we estimate that more than 2 million turtles have been legally taken in these countries, with current levels < 60% of those in the 1980s. Main conclusions Our results provide the most comprehensive global synthesis of the legal take of turtles in recent years and suggest that legal take has the potential to be a driver of marine turtle population dynamics, comparable to mortality estimates through recorded bycatch. However, it is likely that illegal take, along with bycatch, is significantly under-recorded and far greater than the total level of directed legal take. This hampers the ability to assess the relative impacts of these threats to marine turtles. [ABSTRACT FROM AUTHOR]

Aim To examine the potential of remotely sensed abiotic measures as surrogates for the abundance, diversity and community composition of temperate rocky reef fishes and sessile invertebrates. Location Batemans Marine Park, south-eastern Australia. Methods We used high-resolution bathymetric side-scan sonar imagery to quantify abiotic measures of rocky reef habitat, within a marine protected area ( MPA), and examine the relationship between abiotic measures and (1) sessile invertebrate abundance, (2) sessile invertebrate species richness, (3) total fish abundance, (4) fish species richness, and (5) Monacanthidae abundance using generalized additive mixed models ( GAMMs). We chose GAMMs as the preferred statistical analysis to account for the spatial autocorrelation present in our data. Results We found a strong positive relationship between abiotic measures and sessile invertebrate abundance and diversity ( r2 > 0.64). By far the most important predictor was vertical relief within a 75 m radii seascape surrounding the faunal survey. Overall, abiotic measures were poor predictors of total fish abundance ( r2 = 0.175) and fish species richness ( r2 = 0.276), with minimum adequate models producing low explanatory power. In contrast, Monacanthids exhibited a strong positive relationship with abiotic variables ( r2 = 0.385), with increased abundance associated with greater depth and distance from soft sediment. Main conclusions Remotely sensed abiotic measures are important predictors in describing the spatial patterns of sessile invertebrate abundance and diversity and Monacanthid abundance. In contrast, abiotic variables were poor predictors of total fish abundance and diversity. Habitat could be a useful cost-effective surrogate to determine areas of conservation value for certain temperate rocky reef assemblages. This information is valuable for future MPA development and design. [ABSTRACT FROM AUTHOR]

Aim A species-accumulation curve may represent a direct expression of β-diversity, the rate at which diversity increases from local to regional scale. Patterns of variation in β-diversity tend to be consistent when measured across lower levels of the Linnaean taxonomic hierarchy (i.e. using species, genera or families). Our aim was to assess the relationships between species-accumulation curves and β-diversity at different taxonomic levels and to combine the logic of species-accumulation curves with taxonomic surrogacy to provide a new approach for cost-effective and reliable estimates of large-scale species richness (γ-diversity). Location Mediterranean, N Atlantic and SW Pacific. Methods We provide here a novel framework to extrapolate quantitative measures of species richness in large areas from accumulation curves based on extensive sampling at the family level coupled with estimation of species-to-family ratios from a subset of sampling units where organisms are identified to the species level. We demonstrated the effectiveness of the approach by analysing six datasets of diverse marine molluscan assemblages from different biogeographical regions and habitat types. Results The approach proposed here can be used successfully to gain substantial efficiencies in sampling, potentially reducing the number of sampling units in which organisms have to be identified at species level between 50 and 75%, while still allowing reliable estimates of regional species richness. Main conclusions Our results highlight the potential of this approach to improve the general exploration of biodiversity, especially for large-scale monitoring programs. The method we propose differs from previously described approaches by taking into account the spatial heterogeneity of species distributions within the sampled area and also by relying on estimates of species-to-family ratios obtained directly from the specific area of interest. [ABSTRACT FROM AUTHOR]

Aim Multinational collaboration is important for successfully protecting marine environments. However, few studies have assessed the costs and benefits incurred by taking collaborative action. One of the most complex marine regions in the world is the Mediterranean Sea biodiversity hotspot. The sea is shared by over 20 countries across three continents with a vast array of socio-economic and political backgrounds. We aimed to examine how collaboration between countries of the Mediterranean Sea affects conservation plans when costs and threats are considered. Location The Mediterranean Sea. Methods We compared three collaboration scenarios to test the efficiencies of coordinated marine conservation efforts: full coordination between Mediterranean countries, partial coordination within continents and no coordination where countries act in isolation. To do so, we developed four basin-wide surrogates for commercial and recreational fishing effort in the Mediterranean Sea. Using a systematic decision support tool ( Marxan), we minimized the opportunity costs while meeting a suite of biodiversity targets. Results We discovered that to reach the same conservation targets, a plan where all the countries of the Mediterranean Sea collaborate can save over two-thirds of the cost of a plan where each country acts independently. The benefits of multinational collaboration are surprisingly unequal between countries. Main conclusions This approach, which incorporates biodiversity, costs and collaboration into a systematic conservation plan, can help deliver efficient conservation outcomes when planning spatially explicit actions within marine environments shared by many countries. [ABSTRACT FROM AUTHOR]

Aim Artificial coastal defence structures are proliferating in response to rising and stormier seas. These structures provide habitat for many species but generally support lower biodiversity than natural habitats. This is primarily due to the absence of environmental heterogeneity and water-retaining features on artificial structures. We compared the epibiotic communities associated with artificial coastal defence structures and natural habitats to ask the following questions: (1) is species richness on emergent substrata greater in natural than artificial habitats and is the magnitude of this difference greater at mid than upper tidal levels; (2) is species richness greater in rock pools than emergent substrata and is the magnitude of this difference greater in artificial than natural habitats; and (3) in artificial habitats, is species richness in rock pools greater at mid than upper tidal levels? Location British Isles. Methods Standard non-destructive random sampling compared the effect of habitat type and tidal height on epibiota on natural rocky shores and artificial coastal defence structures. Results Natural emergent substrata supported greater species richness than artificial substrata. Species richness was greater at mid than upper tidal levels, particularly in artificial habitats. Rock pools supported greater species richness than emergent substrata, and this difference was more pronounced in artificial than natural habitats. Rock pools in artificial habitats supported greater species richness at mid than upper tidal levels. Main conclusions Artificial structures support lower biodiversity than natural habitats. This is primarily due to the lack of habitat heterogeneity in artificial habitats. Artificial structures can be modified to provide rock pools that promote biodiversity. The effect of rock pool creation will be more pronounced at mid than upper tidal levels. The challenge now is to establish at what tidal height the effect of pools becomes negligible and to determine the rock pool dimensions for optimum habitat enhancement. [ABSTRACT FROM AUTHOR]

Aim Understanding patterns in a species' occupancy and abundance across multiple scales is important for management purposes, particularly for protecting threatened species. Here, we develop a new quantitative, multiscale model of occupancy and abundance that characterizes seven types of rarity and one of commonness in high-diversity communities of staghorn coral. We examine how rare species influence coral community structure and explore spatial variability in underlying patterns of community structure in the context of optimizing the data needed to protect biodiversity. Location North-west Pacific Ocean. Methods We present categorical abundance data for 87 species of staghorn corals occurring within 100 sites across five reefs in the north-west Pacific Ocean. We develop a new model that combines measures of global distribution, local distribution and local abundance to describe eight mutually exclusive occupancy-abundance patterns, which can be used to prioritize regional species conservation. Traditional and new analytical approaches are compared to explore how rare species influence multidimensional space and community structure. Results We show that five types of occupancy-abundance relationships exist in staghorn coral assemblages, including four patterns of rarity. The overwhelming majority of species (73%) are rare according to local abundance and/or distribution criteria. Occupancy-abundance patterns are spatially variable in staghorn coral communities, and no single underlying distribution fits all assemblages. Our findings suggest that 54 species are at risk of regional extinction, 30 of which are also classified as 'vulnerable' by the IUCN. Main conclusions Our model demonstrates that multiple occupancy-abundance patterns exist in staghorn coral assemblages. We conclude that 66% of the pool of staghorn coral fauna in the north-west Pacific is at risk of regional extinction. At the locations and scales examined here, occupancy-abundance patterns and the underlying distributions of coral communities are spatially variable, suggesting that it may not be appropriate to apply unified ecological theory to communities with a large proportion of threatened species because this may jeopardize biodiversity conservation. [ABSTRACT FROM AUTHOR]

Phylogenetically related species share attributes that lead to common responses to environmental conditions, but which could also produce the exclusion of species by its relatives. These processes could generate the patterns of phylogenetic attraction or repulsion in local communities, where related species would tend to coexist more or less than expected by chance. This paper aims to (1) analyse the phylogenetic structure of a benthic gastropod assemblage in the south-western Atlantic Ocean (SAO); (2) explore the linkages between phylogenetic structure and spatial distribution patterns; (3) compare outcomes driven by the analysis of presence-only data and predictive species distribution models; and (4) explore which aspects of the gained knowledge can be useful to the design of sound conservation and/or management actions. Uruguayan shelf and slope in the SAO. Spatial patterns in taxonomical relatedness were assessed using (1) raw presence/absence data (i.e. realized niche approach) and (2) reconstruction of the potential composition of the assemblage from niche modelling (i.e. fundamental niche approach). Null models were used to test hypotheses on assemblage structure. Significant departures from the null hypothesis that all species were drawn from the same assemblage were observed irrespectively of the approach, indicating the existence of non-random structures. However, a high proportion of local communities can be thought as random subsets of the regional species pool. This lack of a strong signal of a taxonomic effect could be related to the absence of a linkage between taxonomic distances and ecological similarities. Our results suggest a random assembly of local communities from the regional species pool and/or niche filtering independent of phylogeny as main determinants of local community composition. We also suggest that local assemblages displaying significantly higher (or lower) than expected taxonomic relatedness should be taken into consideration for designing spatially explicit conservation measures. [ABSTRACT FROM AUTHOR]

Sandy beaches line most of the world's oceans and are highly valued by society: more people use sandy beaches than any other type of shore. While the economic and social values of beaches are generally regarded as paramount, sandy shores also have special ecological features and contain a distinctive biodiversity that is generally not recognized. These unique ecosystems are facing escalating anthropogenic pressures, chiefly from rapacious coastal development, direct human uses — mainly associated with recreation — and rising sea levels. Beaches are increasingly becoming trapped in a ‘coastal squeeze’ between burgeoning human populations from the land and the effects of global climate change from the sea. Society's interventions (e.g. shoreline armouring, beach nourishment) to combat changes in beach environments, such as erosion and shoreline retreat, can result in severe ecological impacts and loss of biodiversity at local scales, but are predicted also to have cumulative large-scale consequences worldwide. Because of the scale of this problem, the continued existence of beaches as functional ecosystems is likely to depend on direct conservation efforts. Conservation, in turn, will have to increasingly draw on a consolidated body of ecological theory for these ecosystems. Although this body of theory has yet to be fully developed, we identify here a number of critical research directions that are required to progress coastal management and conservation of sandy beach ecosystems. [ABSTRACT FROM AUTHOR]

Demographic and life-history attributes of the mole crab Emerita brasiliensis were analysed along 2700 km of the Atlantic coast of South America, including sandy beaches at the southernmost limit (Uruguay) and at the core of its geographical range (Brazil). Population features varied markedly within this range and exhibited systematic geographical patterns of variation. Abundance significantly increased from temperate to subtropical beaches, and the same held true for the asymptotic weight of males. Conversely, length at maturity and asymptotic weight of females increased from subtropical to temperate beaches, being inversely related to sea water temperature. Macroecological patterns in abundance and body weight showed the first large-scale evidence of scaling of population density to body size for a sandy beach population. Mortality rates (both sexes) followed a nonlinear increase from low-density temperate beaches to high-density subtropical beaches. The effect of habitat quality and availability could explain discontinuities in the species distribution within its range, and also differential responses in life-history attributes at a local scale. Asymmetries and converse latitudinal trends between sexes suggest that there is not a single general factor determining large-scale patterns in life-history traits of this species. Our results reinforce the view that density-dependent and environmental factors operating together regulate sandy beach populations. The need to develop macroecological studies in sandy beach ecology is highlighted, as knowledge acquired from local to large spatial scales throws light on population structure and regulation mechanisms. [ABSTRACT FROM AUTHOR]