Fish taxonomic,functional, and phylogenetic diversity and their vulnerabilities in the largest river in southeastern China

1. Freshwater biodiversity is currently under multiple threats. Conservation of freshwater fish biodiversity needs to be prioritized because natural conservation resources are always limited.
2. Samples were collected at 24 sites in the Min River, the largest basin in southeastern China. Taxonomic, functional, and phylogenetic diversity were analyzed. Biodiversity vulnerability was measured by removing one species each time out of the community with replacement.
3. Results suggested that hotspots for taxonomic and phylogenetic diversity were located at two impounded sites, while for functional diversity were those sites with no upstream dams. Little congruence was observed between taxonomic, functional, and phylogenetic diversity. Fragmentation of river network connectivity caused by dams was a significant factor affecting the biodiversity patterns. Beta turnover was the driving component for beta diversity, indicating that biodiversity dissimilarity along the river was mostly explained by environmental sorting. Fifteen out of 16 species that contributed the most to different facets of biodiversity were mostly endemic, either they had distinctive functional traits or they were the most prevalent species. Sites with the highest diversity vulnerability were characterized by these distinctive species. Functional diversity was more vulnerable to species loss comparing with the other two biodiversity facets.
4. Prioritizing those biodiversity hotspots, sites with extreme functional vulnerability, and those distinctive endemic species which contributed the most to biodiversity vulnerability is suggested in the Min River. The study found evidence that congruence among different facets of biodiversity is hard to achieve, and functional diversity is the most vulnerable in a freshwater system fragmented by intensive dam constructions. This work will help to develop systematic conservation planning from the perspective of different biodiversity facets.

     

新疆阿勒泰地区额尔齐斯河和乌伦古河流域鱼类多样性演变和流域健康评价

为了解阿勒泰地区额尔齐斯河和乌伦古河流域的鱼类多样性现状和历史演变, 本研究于2013-2016年间在该流域的鱼类多样性进行了连续调查, 并结合历史资料和标本, 以Margalef丰富度指数、Shannon-Wiener多样性指数、Pielou均匀度指数分析评估了流域内鱼类的多样性水平和时空变化。该流域历史上分布有土著鱼类23种, 当前记录到19种, 流域内还有外来鱼类15种。阿勒泰鱼类的区系组成以鲤科种类为主, 其中特有和珍稀濒危物种占比高, 具有重要的保护价值。多样性指数计算结果显示, 2013-2016年鱼类多样性情况整体稳定, 额尔齐斯河鱼类物种数多于乌伦古河。研究还基于鱼类生物完整性指数(Fish Index of Biological Integrity, F-IBI)对34个采集点的河流健康状况进行了评价, 结果显示额尔齐斯河流域大多数调查点的健康状况处于“亚健康”或“一般”水平, 乌伦古河流域多数调查点的健康状况处于“健康”水平。水利工程、外来物种、过度捕捞是影响阿勒泰地区鱼类多样性的重要因素。未来应通过水利工程的联合调度、下泄合理生态流量、布设鱼类通道、规范养殖渔业、严控外来物种、本地土著鱼类的人工增殖放流, 以及合理的就地保护措施对阿勒泰地区的鱼类多样性加以保护, 提升水体健康程度。     

黄河流域淡水鱼类多样性和保护

本文介绍了黄河流域鱼类研究的历史、淡水鱼类的物种组成、整体分布格局、特有性、濒危性, 以及鱼类多样性在黄河上、中、下游等的特点。历史上对于黄河鱼类多样性的研究, 历经了四个阶段, 从最初的零星记录一直到现阶段的深入研究。综合历史记录和野外调查, 已知黄河流域分布的淡水鱼类共计147种, 隶属于12目21科78属, 其中鲤形目种类占据绝对优势。另外, 全流域黄河特有种计有27种, 受危物种24种, 分别占总数的18.37%和16.32%。同中国主要江河相比, 黄河鱼类在高级分类阶元上的多样性较高, 但物种多样性则处在较低水平; 尽管黄河特有鱼类和受危物种比例低于全国平均水平, 但上游特有鱼类和珍稀濒危鱼类的占比很高。目前黄河鱼类多样性大幅降低, 现状调查仅能采获历史记录种类的53.06%。梯级水电开发、水资源过度利用、外来物种、水域污染和过度捕捞都是威胁鱼类多样性的重要因素, 但对各河段和支流的影响不一, 应做出有针对性的保护部署。     

Ecoregion Prioritization Suggests an Armoury Not a Silver Bullet for Conservation Planning

In the face of accelerating species extinctions, map-based prioritization systems are increasingly useful to decide where to pursue conservation action most effectively. However, a number of seemingly inconsistent schemes have emerged, mostly focussing on endemism. Here we use global vertebrate distributions in terrestrial ecoregions to evaluate how continuous and categorical ranking schemes target and accumulate endangered taxa within the IUCN Red List, Alliance for Zero Extinction (AZE), and EDGE of Existence programme. We employed total, endemic and threatened species richness and an estimator for richness-adjusted endemism as metrics in continuous prioritization, and WWF''s Global200 and Conservation International''s (CI) Hotspots in categorical prioritization. Our results demonstrate that all metrics target endangerment more efficiently than by chance, but each selects unique sets of top-ranking ecoregions, which overlap only partially, and include different sets of threatened species. Using the top 100 ecoregions as defined by continuous prioritization metrics, we develop an inclusive map for global vertebrate conservation that incorporates important areas for endemism, richness, and threat. Finally, we assess human footprint and protection levels within these areas to reveal that endemism sites are more impacted but have more protection, in contrast to high richness and threat ones. Given such contrasts, major efforts to protect global biodiversity must involve complementary conservation approaches in areas of unique species as well as those with highest diversity and threat.     

Conservation Planning for Offsetting the Impacts of Development: A Case Study of Biodiversity and Renewable Energy in the Mojave Desert

Balancing society’s competing needs of development and conservation requires careful consideration of tradeoffs. Renewable energy development and biodiversity conservation are often considered beneficial environmental goals. The direct footprint and disturbance of renewable energy, however, can displace species’ habitat and negatively impact populations and natural communities if sited without ecological consideration. Offsets have emerged as a potentially useful tool to mitigate residual impacts after trying to avoid, minimize, or restore affected sites. Yet the problem of efficiently designing a set of offset sites becomes increasingly complex where many species or many sites are involved. Spatial conservation prioritization tools are designed to handle this problem, but have seen little application to offset siting and analysis. To address this need we designed an offset siting support tool for the Desert Renewable Energy Conservation Plan (DRECP) of California, and present a case study of hypothetical impacts from solar development in the Western Mojave subsection. We compare two offset scenarios designed to mitigate a hypothetical 15,331 ha derived from proposed utility-scale solar energy development (USSED) projects. The first scenario prioritizes offsets based precisely on impacted features, while the second scenario offsets impacts to maximize biodiversity conservation gains in the region. The two methods only agree on 28% of their prioritized sites and differ in meeting species-specific offset goals. Differences between the two scenarios highlight the importance of clearly specifying choices and priorities for offset siting and mitigation in general. Similarly, the effects of background climate and land use change may lessen the durability or effectiveness of offsets if not considered. Our offset siting support tool was designed specifically for the DRECP area, but with minor code modification could work well in other offset analyses, and could provide continuing support for a potentially innovative mitigation solution to environmental impacts.     

Impact of human activities on changes of ichthyofauna in Dongjin River of Korea in the past 30 years

Ichthyofauna and fish community were investigated at 17 representative stations of the Dongjin River drainage system from spring to fall in 2014. The survey resulted in a list of 53 species belonging to 14 families structured into 4 distinctive parts along the river: uppermost-stream, upper-stream, mid-stream, and lower-stream. Comparison of species lists with 30-year interval exhibited significant decreases in peripheral freshwater fishes, Acheilognathinae, endemic, and indigeneity species, but increases in exotic, epipelagic, and lentic species. Moreover, in the estuary of the Dongjin River drainage system, peripheral freshwater fish species were replaced by pure freshwater fish species due to the Saemangeum sea-wall project. In the upper region of the river, introduced eight alien species from Seomjin River via water diversion tunnels. In the mid-lower region, the construction of floodgates and numerous small weirs caused expansion of lentic water areas, facilitating the spread of problematic exotic species such as Micropterus salmoides, Lepomis macrochirus, and Carassius cuvieri. Also, water deterioration in this region resulted in an increase of tolerant species and a decrease of sensitive and endemic species. Our results suggest that a recovery strategy for a healthy ecosystem in the Dongjin River drainage system should reflect this compartmentalized cause and effect on the changes of icthyofauna.     

The contribution of scientific information to the conservation and management of freshwater biodiversity in tropical Asia

Tropical Asia (i.e. the Oriental biogeographic region) is the most densely populated and degraded region on Earth with the highest deforestation rates in the tropics. Flow regulation is a significant threat to riverine biodiversity in the region, and its impacts are combined with overharvesting, pollution and other sources of habitat degradation. In addition to these immediate threats, the potential impacts of exotic species and climate change are difficult to predict. Uncertainty about impact effects arises also from the fact that knowledge of the rich freshwater biodiversity of tropical Asia is incomplete, and up-to-date national or regional inventories are lacking. In part, this reflects taxonomic constraints, and a limited representation of Asian science in the international limnological and conservation literature. A survey of recent (1992–2001) international journals dealing with freshwater ecology and limnology in general, on one hand, and conservation biology on the other, reveal that the representation of scientists based in tropical Asia was extremely low. Scientists from tropical Asia authored fewer than 2% of more than 4500 papers dealing with freshwater biology; 57% of them were published in Hydrobiologia. Less than 0.1% of freshwater biology papers dealt with the conservation of biodiversity in tropical Asian fresh waters. The representation of Asian freshwater science in the conservation biology literature was also poor; 0.6% of 1880 papers surveyed. Such limited dissemination of information reflects a variety of constraints (e.g. manpower, funding, language, and entrenched attitudes), arising from sources both within and outside the region. Even the data that are published are not effectively deployed toward conservation ends. Awareness of some of the more egregious examples of overharvesting (e.g. of river turtles) in the region has increased, but strategies for the protection of riverine biodiversity remain underdeveloped. Where legislation to protect water resources has been put in place, it has been directed towards enhancing human use of water – not biodiversity conservation – and enforcement is weak. Exceptionally, the Chinese government has produced national `Red Data Books' for endangered freshwater vertebrates, and legislation aimed at protecting species at risk, particularly from overharvesting, are in place. Huge obstacles remain, especially in the management of rivers crossing international boundaries. The Mekong River Commission (MRC) provides an example of a model for an international drainage basin that has made significant progress in establishing appropriate structures and mechanisms for sustainable development in a challenging political landscape. Not all of the Mekong riparian states participate in the MRC, and this will be essential for sustainable management. However, even within national borders, local interests can override drainage-basin perspectives. In many places in Asia, preservation of near-pristine freshwater environments is not a realistic option. Sustaining human livelihoods is an over-riding concern, and recognition of this fact must be built in to biodiversity conservation efforts. This has special implications for the management of exotic species, as the example of fish introductions to the Sepik River in Papua New Guinea shows. Notwithstanding the various factors that constrain publication by scientists in tropical Asia, we must recognise that poor dissemination research results will have consequences for the long-term preservation of the habitats and biodiversity that we study. A change in research strategy that establishes priorities, recognises the inevitability of trade-offs, and includes greater emphasis on engagement and partnerships – as in the MRC – is mandated.     

厦门市重点保护植物空间优先保护格局研究

生物多样性保护对维持城市生态系统功能具有重要意义。以39种厦门市重点保护植物为对象,通过物种分布模型MaxENT获得物种潜在分布栅格图,利用空间保护优先化定量工具Zonation软件识别理论上既适宜重点保护植物生存又能够保证景观连通性的区域,获得本地重点保护植物景观保护等级。根据2020年全球生物多样性目标,将景观保护等级最高的17%区域视为多物种空间优先保护区,结合Zonation模型生成的随景观丧失物种加权灭绝风险曲线,将保护等级最高的8%区域划为一级保护区,保护等级在8%-17%范围内的区域划为二级保护区。利用MaxENT模型中的jackknife刀切法发现海拔是对本地重点保护植物分布影响最大的环境因子,优先保护区集中分布于海拔较低的海岸带区域。将优先保护区与自然保护地建设现状、厦门市生态功能区规划、土地利用规划、城市总体规划对比发现厦门市岛外西部、北部的优先保护区得到了较好保护;岛外的西南部及东南部、岛内的东部及南部海岸带的优先保护区被建设用地大规模占用,已纳入自然保护地范围的区域较少,存在大量的海岸带优先保护区保护空缺;岛外东南部的部分优先保护区虽未被占用,但规划中属发展备用地,缺乏生态保护。为避免优先保护区面积的进一步萎缩,应重点关注海岸带区域优先保护区的生态保护,将目前属于发展备用地的优先保护区转划为生态留白空间,针对一级、二级优先保护区分别实施刚性和弹性的生态保育措施,在保护生物多样性的同时,严控对海岸带区域优先保护区的进一步开发利用,协调优先保护区内保护与开发利用间的关系。     

We need better understanding about functional diversity and vulnerability of tropical freshwater fishes

Here we extend a discussion initiated by Toussaint et al. (Sci Rep 6:22125, 2016) concerning the relationship between global patterns of freshwater fish functional diversity (FD) and its vulnerability to human impacts. Based on a set of morphological traits, they concluded that Neotropical freshwater fishes have highest FD, but low vulnerability given high levels of functional redundancy. This conclusion implies that conservation efforts for freshwater fishes should emphasize temperate regions. This perspective is risky, because Toussaint et al.’s study seriously underestimates the full scope of FD, including important ecosystem services provided by fishes in the tropics. We briefly discuss some additional and well-documented aspects of tropical freshwater fish FD and conclude that tropical fish FD is highly vulnerable.     

Conservation of freshwater biodiversity in Oriental Asia: constraints, conflicts, and challenges to science and sustainability

Freshwater ecosystems in Asia are under grave threat. Large and growing human populations and the rapid pace of development have led to the degradation of natural environments throughout the region. Conservation of freshwater biodiversity faces particular challenges because of a lack of public awareness of its magnitude and importance. Even taxa with high public-relations value, such as fishes, are rather poorly known, and the variety of other animals associated with lakes and riverine wetlands, including charismatic and endangered megafauna, seems to have escaped wide attention. The rate and extent of environmental change in Asia are having impacts on the aquatic biota that may be greater than anywhere else on the planet. Particular threats include water pollution, from point and nonpoint sources, which is almost ubiquitous; overharvest of fishes, turtles, and crocodilians; flow regulation and impoundment of rivers; as well as drainage basin degradation and climate change. Many lakes have been so modified by human activities that they function as enormous fishponds, and the introduction of exotic species (especially, but not only, fishes) or the translocation of native taxa has contributed to the extinction of endemic species in isolated drainage basins. The prognosis is grim, and we can anticipate a loss in biodiversity and homogenization of the regional biota. Reversal of these trends will require a change in focus by limnologists and water-resource managers, and the urgent adoption of a conservation agenda for freshwater science in Asia. Received: March 27, 2000 / Accepted: June 30, 2000     

Insect conservation and pest management

The issue of insect conservation in pest management has many conflicting aspects. For instance, it is desirable to conserve a pest residue in order to maintain natural enemy population and it is imperative to conserve natural enemies. However, conservation of pest species is not relevant if the pest species is an exotic invader and a candidate for eradication, mainly because eradication, if successful, achieves only regional extinction. Conservation of native pests depends, to a large extent, on whether the species is a direct pest of a high value crop or an indirect pest with an acceptable economic injury level. In this paper, integrated pest management is defined in terms of sustainable agriculture and the conservation of biodiversity, and give five premises that stress the level of disturbance of agricultural communities and the dynamics of pest status for arthropod species in the community. The possible impacts of the main integrated pest management tactics on arthropod conservation are tabulated and the results reached stress that diversification of agricultural systems through maximum use of native plants should benefit both integrated pest management and regional arthropod conservation.     

Length–weight relationships of freshwater fishes of the Alto Madre de Dios River (Manu Biosphere Reserve,Peru)

The present work provides the estimates of morphometric relationships for 22 native freshwater fish species (11 Characidae, five Loricariidae, two Heptapteridae, one Astroblepidae, one Crenuchidae, one Curimatidae and one Erythrinidae) collected in the Alto Madre de Dios River (Cuzco and Madre de Dios, Peru) in June 2012 using a mobile backpack electrofishing unit. These are the first length–weight relationships reported for 24 species, mostly endemic to the Amazonian basin. Knowledge regarding these biometric relationships can be relevant in the management and conservation of the local fishes and fisheries.     

Prioritizing species for conservation planning

The efforts to protect biological diversity must be prioritized because resources for nature conservation are limited. Conservation prioritization can be based on numerous criteria, from ecological integrity to species representation, but in this review I address only species-level prioritization. Criteria used for species prioritization range from aesthetical to evolutionary considerations, but I focus on the aspects that are biologically relevant. I distinguish between two main aspects of diversity that are used as objectives: Maintenance of biodiversity pattern, and maintenance of biodiversity process. I identify two additional criteria typically used in species prioritization that serve for achieving the objectives: The species’ need of protection, and cost and effectiveness of conservation actions. I discuss how these criteria could be combined with either of the objectives in a complementarity-based benefit function framework for conservation prioritization. But preserving evolutionary process versus current diversity pattern may turn out to be conflicting objectives that have to be traded-off with each other, if pursued simultaneously. Although many reasonable criteria and methods exist, species prioritization is hampered by uncertainties, most of which stem from the poor quality of data on what species exist, where they occur, and what are the costs and benefits of protecting them. Surrogate measures would be extremely useful but their performance is still largely unknown. Future challenges in species prioritization lie in finding ways to compensate for missing information.     

Distribution pattern, threats and conservation of fish biodiversity in the East Tiaoxi, China

East Tiaoxi River is one of the largest inflowing rivers into Taihu Lake, and the fish fauna in the river is poorly understood. In the present study, an extensive survey of fish was conducted in October and November 2009, May and September 2010 and May 2011 covering a total of 55 sites along the whole river. A total of 84 freshwater fish species belonging to 8 orders, 18 families and 52 genera have been recorded. Among these are 35 species endemic to China, and 3 newly recorded exotic species. The fish composition varies greatly from headwaters to downstream. Based on cluster analysis with presence-absence data, the East Tiaoxi River is divided into four regions, specifically, the upper reach, middle-up reach, middle reach and lower reach. It is observed that species richness and the proportion of omnivorous species increased from upstream to downstream while the proportion of invertivorous species decreased consequently. Habitat alteration, overfishing, pollution and inland navigation adversely affect the fish diversity and ecosystem functioning in the East Tiaoxi River. To protect fish diversity more effectively in the area, the conservation of fish biodiversity in the North Tiaoxi River and Middle Tiaoxi River should be considered as a priority. Meanwhile, shallow zones or backwater areas should be created in the middle-lower reaches. Furthermore, river restoration, in terms of habitat creation, should be considered to protect the structure and diversity of fish communities, halt the progressive deterioration of freshwater ecosystems and sustain a valuable ecological resource for humans.     

Distribution of freshwater macroinvertebrates in streams with dams and associated reservoirs on a subtropical oceanic island off southern Japan

The conservation of endemic fauna in freshwater ecosystems is a topical issue on small oceanic islands. Because these endemics have limited distributions, they are more vulnerable to extinction. This study is the first to clarify the distribution of freshwater macroinvertebrates including endemic and alien species in streams with dams and associated reservoirs on the Ogasawara Islands in the northwestern Pacific Ocean. In 2007, we conducted a field survey in streams and reservoirs of the Yatsuse River system and collected 22 taxonomic groups from 13 stations. Hierarchal cluster analysis and non-metric multi-dimensional scaling (NMDS) were performed for the presence/absence data of the macroinvertebrates, and the results indicated that (1) most of endemic species were present in inlet streams of dam reservoirs, (2) these endemic species were absent in the bottom sediments of the reservoirs because of oxygen depletion and (3) dams may be barriers to the migration of some species of amphidromous crustaceans. Because human modifications, such as dams and associated reservoirs, on a small oceanic island can rapidly result in fragmentation or loss of freshwater habitats of endemic species, the remaining habitat of these species, such as headwater streams, must be protected and preserved to avoid species extinction.     

Introduction,distribution, spread,and impacts of exotic freshwater gastropods in Texas

We examined the patterns of distribution, vectors of introduction, and potential ecological impacts of freshwater exotic species in Texas over the last 45 years. Currently, five species of exotic gastropods are established: channeled-type applesnail (Pomacea insularum), red-rim melania (Melanoides tuberculatus), quilted melania (Tarebia granifera), giant rams-horn snail (Marisa cornuarietis), and Chinese mysterysnail (Cipangopaludina chinensis). In contrast to the northern part of the US, where shipping appears to be the most important vector for the introduction of aquatic invasive species, aquarium and ornamental trade dominated among unintentional vectors of introduction of all freshwater exotics in Texas, resulting in different patterns of distribution, spread, and ecological impacts. The rate of spread of exotic gastropods in Texas varied from 39 waterbodies colonized over 18 years for P. insularum to only three waterbodies during last 45 years for C. chinensis. Four of five exotic gastropods were found in highly vulnerable aquifer-fed springs and rivers, which contain numerous endemic and endangered species. The fifth species, Pomacea insularum, is an agricultural pest. Potential negative ecological effects of exotic gastropods include impacts on wetlands and wetland restoration, competitive exclusion of native snails, and the introduction of exotic parasites, trematodes, which could infect fish and waterfowl, including federally protected species. Aquifer springs with stable temperature regimes are refuges for both cold and warm intolerant species. Handling editor: D. Dudgeon     

Host-parasite interactions in oligotrophic stream ecosystems: the roles of life-history strategy and ecological niche

Biodiversity in fluvial ecosystems is under pressure as a consequence of their degradation. Conservation strategies for endangered freshwater molluscs and for salmonid fishes have been proposed but they are typically poorly integrated. Here, we examined for the first time the genetic structure of a critically endangered obligate mollusc invertebrate parasite, the freshwater pearl mussel ( Margaritifera margaritifera ), and its vertebrate host fish, the brown trout ( Salmo trutta m. fario ), in European headwater streams. We compared genetic differentiation and diversity with productivity and ecological habitat features of both species in nine different European streams from the drainage systems of the Danube, Elbe, Weser, Tuuloma, Kemijoki and Aulne. Genetic differentiation was more pronounced in pearl mussel than in brown trout, although the drainage-specific patterns were generally similar. Genetic diversity of host and parasite was negatively correlated. The most oligotrophic, postglacially colonized areas represented genetic diversity hotspots with high conservation priority for pearl mussels, whereas their host fish displayed low diversity in these areas. This pattern can be explained by differences in the ecological niches and in the life-history strategies of both species. These results question the effectiveness of single-species approaches in the conservation of genetic aquatic resources and suggest that genetic information from species with different life-history strategies, such as invertebrates and fish, should be considered simultaneously for geographical conservation prioritization in stream ecosystems.     

Aquatic biodiversity in the Mediterranean climate rivers of southwestern Australia

Southwestern Australia is recognised as a global biodiversity hotspot, characterised by high diversity and endemism of vascular terrestrial plants. However, the significance of its freshwater biodiversity is not well understood. This review provides an updated account of species richness in rivers in the Mediterranean region (med-region) of southwestern Australia. Taxonomic knowledge of many aquatic invertebrate groups in this region has improved significantly in the last two decades as a result of ecological surveys and government funding for taxonomic research. Of the 662 species of plants and animals surveyed, 43% were found to be endemic to the region, yet when taxonomic groups were considered separately, levels of endemism were varied. To date, few aquatic species from the med-region are listed as threatened; however, many more species would be expected to be included if assessed against appropriate criteria. Conservation efforts are focussed on climate change mitigation and managing the impacts of broad scale land clearing for agriculture. Reserve design and location of important nature reserves on the extreme south coast, limits the ability for species’ movement to cooler, wetter regions. This will necessitate supporting restoration which leads to increased resilience in freshwater ecosystems to withstand the combined effects of climate change and land use.     

BIODIVERSITY RESEARCH: Geographical linkages between threats and imperilment in freshwater fish in the Mediterranean Basin

Aim The level of imperilment of mediterranean freshwater fish is among the highest recorded for any group of organisms evaluated to date. Here, we describe the geographical patterns in the incidence of threats affecting mediterranean freshwater fish and test whether the effects of specific threats are spatially related to the degree of imperilment of fish faunas. Location The Mediterranean Basin Biome. Methods From the IUCN Red List, we recorded the six main threats to 232 endemic freshwater fish species. We used data on fish distributions from IUCN to characterize the spatial patterns in the incidence of threats (as percentage of species affected) through multivariate statistics. We studied the relationships between threat incidence and two estimators of imperilment (proportion of species threatened and an index of extinction risk) at two spatial scales (10 × 10 km and basins) using partial least squares regressions (PLSR) that incorporated the effects of species richness and mean range size. Results The main axis of variation in the incidence of threats to freshwater fish split areas mainly affected by invasive species from those areas where species are threatened by pollution and agriculture. Wherever invasive species and water extraction were predominant threats, fish assemblages consistently tended to be more imperilled. Main conclusions As far as we know, this is the first large‐scale analysis on the spatial relationships between the incidence of threats and level of imperilment of any taxonomic group. Our results highlight the primary role of invasive species and water extraction as drivers of native fish declines in the Mediterranean Basin. Large‐scale patterns described here should be generated by local‐scale impacts of both threats on fish biodiversity, widely reported in Mediterranean areas. Because all the species under concern are endemic, control of invasive species and reducing overexploitation of freshwater resources should be conservation priorities for mediterranean freshwater systems.     

Key Neotropical ecoregions for conservation of terrestrial vertebrates

Conservation planning analyses show a striking progression from endeavors targeted at single species or at individual sites, to the systematic assessment of entire taxa at large scales. These, in turn, inform wide-reaching conservation policies and financial investments. The latter are epitomized by global-scale prioritization frameworks, such as the Biodiversity Hotspots. We examine the entire Neotropical region to identify sets of areas of high conservation priority according to terrestrial vertebrate distribution patterns. We identified a set of 49 ecoregions in which 90, 82 and 83%, respectively of total, endemic and threatened vertebrates are represented. A core subset of 11 ecoregions captured 55, 27 and 38% of these groups. The Neotropics hold the largest remaining wilderness areas in the world, and encompass most of the tropical ecosystems still offering significant options for successful broad-scale conservation action. Our analysis helps to elucidate where conservation is likely to yield best returns at the ecoregion scale.