Freshwater ecosystems are highly biodiverse1 and important for livelihoods and economic development2, but are under substantial stress3. To date, comprehensive global assessments of extinction risk have not included any speciose groups primarily living in freshwaters. Consequently, data from predominantly terrestrial tetrapods4,5 are used to guide environmental policy6 and conservation prioritization7, whereas recent proposals for target setting in freshwaters use abiotic factors8, 9, 10, 11, 12-13. However, there is evidence14, 15, 16-17 that such data are insufficient to represent the needs of freshwater species and achieve biodiversity goals18,19. Here we present the results of a multi-taxon global freshwater fauna assessment for The IUCN Red List of Threatened Species covering 23,496 decapod crustaceans, fishes and odonates, finding that one-quarter are threatened with extinction. Prevalent threats include pollution, dams and water extraction, agriculture and invasive species, with overharvesting also driving extinctions. We also examined the degree of surrogacy of both threatened tetrapods and freshwater abiotic factors (water stress and nitrogen) for threatened freshwater species. Threatened tetrapods are good surrogates when prioritizing sites to maximize rarity-weighted richness, but poorer when prioritizing based on the most range-restricted species. However, they are much better surrogates than abiotic factors, which perform worse than random. Thus, although global priority regions identified for tetrapod conservation are broadly reflective of those for freshwater faunas, given differences in key threats and habitats, meeting the needs of tetrapods cannot be assumed sufficient to conserve freshwater species at local scales.
Urine, which has a high concentration of urea, can be used as a sustainable resource for nutrient recovery and sustainable energy. However, urea undergoes hydrolysis, catalyzed by urease, generating ammonia and carbon dioxide. As ammonia is released during hydrolysis in stored urine, the pH rises progressively until the pKa of ammonium is reached (i.e., 9.3). At elevated pH levels, struvite and other related precipitates are formed. These reactions lower the efficiency of ammonia and urea nitrogen recovery and often cause scaling, pipe blockage, and odors. Herein, we explore an approach to stabilize urea, using pharmaceuticals and their metabolites that are commonly present in human urine. Based on a survey of the urease inhibitory effects of twenty-three pharmaceuticals and metabolites, we determined that the polyphenolic and disulfide-containing compounds had the highest urease inhibition efficiency. Specifically, outstanding inhibitors include catechol (CAT), hydroquinone (HYD), and disulfiram (DSF). Furthermore, when added to urine, these compounds resulted in the retardation of urease-catalyzed hydrolysis, leading to longer-term urine stabilization upon storage. Reaction mechanisms for urease inhibition by polyphenolics and disulfiram are proposed. Evidence is provided that pharmaceutical metabolites can stabilize urea and thus could lead to a sustainable method for nitrogen nutrient recovery from stored urine.
Clarifying the formation mechanism of single-atom sites guides the design of emerging single-atom catalysts (SACs) and facilitates the identification of the active sites at atomic scale. Herein, a molten-salt atomization strategy is developed for synthesizing zinc (Zn) SACs with temperature universality from 400 to 1000/1100 °C and an evolved coordination from Zn-N2Cl2 to Zn-N4. The electrochemical tests and in situ attenuated total reflectance-surface-enhanced infrared absorption spectroscopy confirm that the Zn-N4 atomic sites are active for electrochemical carbon dioxide (CO2) conversion to carbon monoxide (CO). In a strongly acidic medium (0.2 m K2SO4, pH = 1), the Zn SAC formed at 1000 °C (Zn1NC) containing Zn-N4 sites enables highly selective CO2 electroreduction to CO, with nearly 100% selectivity toward CO product in a wide current density range of 100-600 mA cm-2. During a 50 h continuous electrolysis at the industrial current density of 200 mA cm-2, Zn1NC achieves Faradaic efficiencies greater than 95% for CO product. The work presents a temperature-universal formation of single-atom sites, which provides a novel platform for unraveling the active sites in Zn SACs for CO2 electroreduction and extends the synthesis of SACs with controllable coordination sites.
Micropollutants, due to their low concentrations, exceptional chemical stability, and profound toxicity, present a significant challenge in water treatment. While electrocatalysis and photocatalysis have shown promise as potential water purification techniques, their inherent limitations in mass transfer often result in elevated energy requirements and suboptimal efficiency. In this study, a Janus catalytic flow-through membrane (JCFM) was utilized to successfully remove two notorious micropollutants dichlorvos (DDVP) and azoxystrobin (AZX) from water based on the "catch-and-feed" strategy. This membrane adopts a ``sandwich" configuration, comprising platinum-modified reduced titanium (Pt@rTO) as the electrocatalytic layer, porous titanium (Ti) as the current collector, and rTO as the photocatalytic layer. The JCFM exhibited remarkable performance, maintaining an center dot OH energy conversion efficiency of up to 20.12 nM and displaying catalytic activity (k(JCFM) = 6.97 x 10(-4) s(-1)) in degrading AZX far superior to that of photocatalysis (kPC = 9.51 x 10(-5) s(-1)) or electrocatalysis (k(EC) = 9.89 x 10(-5) s(-1)) alone. It is evidenced that the Pt@rTO layer efficiently generates reactive oxygen species (ROS), which, along with the micropollutants, flow through the JCFM ("feed"), which strengthens mass transfer and facilitates efficient reactions within the confined space ("catch"). The ROSs then seep through the rTO layer, where they are reactivated by UV light radiation. The mechanism and the alternative reaction pathway of DDVP and AZX has also been proposed. In sequential testing, the JCFM achieved continuous and energy-efficient removal of micropollutants, exceeding 97.5 % over 200 h. The scale-up application of this technology has proven effective in the treatment of secondary biochemical effluent from municipal sewage, coking wastewater, and landfill leachate, achieving the concurrent degradation of various micropollutants.
Abstract Public policy addressing biodiversity loss is most likely to be effective when it is informed by appropriate evidence and considers potential unintended consequences. We evaluate key evidence relating to the Hunting Trophies (Import Prohibition) Bill that was discussed in the UK Parliament between 2022 and 2024. We characterize the UK's role in international hunting trophy trade by analyzing CITES (Convention on International Trade in Endangered Species of Wild Fauna and Flora) trade data for 2000–2021 and 2015–2021. For CITES‐listed species imported to/exported from the UK as hunting trophies in these periods we use data from the International Union for Conservation of Nature (IUCN) Red List of Threatened Species to determine whether hunting designated as “trophy hunting” is (i) likely a major threat contributing to species being of elevated conservation concern, (ii) likely or possibly causing localized declines, or (iii) not a threat. We then use the Red List to determine whether such hunting provides, or potentially provides, benefits for species and/or people. Finally, we evaluate the UK Government's impact assessment of the bill. In 2000–2021 an estimated 3494 hunting trophies from 73 CITES‐listed species and subspecies were exported to the UK involving an estimated 2549 whole organism equivalents (WOEs), that is, individual animals. Imports involved 158.86 ± 66.53 (mean ± SD) trophies/year (115.83 ± 32.27 WOEs/year). In 2015–2021, 79% of imports were from countries where populations of the hunted species are stable, increasing, or abundant. Legal hunting for trophies is not a major threat to any of the species or subspecies imported to the UK, but likely or possibly represents a local threat to some populations of eight species. This hunting does, or could potentially, benefit 20 species and subspecies, and people. Among other concerns, the impact assessment failed to adequately consider the costs and benefits to local communities in countries where such hunting occurs. Informed by these analyses we discuss alternative regulatory options.
Emerging contaminants are defined as chemicals that are not currently(or have only recently been)regulated and about which there are concerns regarding their impact on human or ecological health.Such contaminants are widely detected in air,water,soil,sediment,and biotic environments.
Alternatives are being developed to replace fluorinated persistent organic pollutants (POPs) listed in the Stockholm Convention, bypass environmental regulations, and overcome environmental risks. However, the extensive usage of fluorinated POPs alternatives has revealed potential risks such as high exposure levels, long-range transport properties, and physiological toxicity. Therefore, it is imperative to rethink the alternatives and their treatment technologies. This review aims to consider the existing destructive technologies for completely eliminating fluorinated POPs alternatives from the earth based on the updated classification and risks overview. Herein, the types of common alternatives were renewed and categorized, and their risks to the environment and organisms were concluded. The efficiency, effectiveness, energy utilization, sustainability, and cost of various degradation technologies in the treatment of fluorinated POPs alternatives were reviewed and evaluated. Meanwhile, the reaction mechanisms of different fluorinated POPs alternatives are systematically generalized, and the correlation between the structure of alternatives and the degradation characteristics was discussed, providing mechanistic insights for their removal from the environment. Overall, the review supplies a theoretical foundation and reference for the control and treatment of fluorinated POPs alternatives pollution.
The IUCN Red List of Threatened Species underpins much decision-making in conservation and plays a key role in monitoring the status and trends of biodiversity. However, the shortage of funds and assessor capacity slows the uptake of novel data and techniques, hampering its currency, applicability, consistency and long-term viability. To help address this, we developed sRedList, a user-friendly online platform that assists Red List assessors through a step-by-step process to estimate key parameters in a standardised and reproducible fashion. Through the platform, assessors can swiftly generate outputs including species' range maps, lists of countries of occurrence, lower and upper bounds of area of occupancy, habitat preferences, trends in area of habitat, and levels of fragmentation. sRedList is compliant with the IUCN Red List guidelines and outputs are interoperable with the Species Information Service (SIS; the IUCN Red List database) in support of global, regional and national assessments and reassessments. sRedList can also help assessors prioritise species for reassessment. sRedList was released in October 2023, with a complete documentation package (including text documentation, ‘cheatsheets’, and 15 video tutorials), and will soon be highlighted in the official Red List online training course. sRedList will help to bridge the gap between extinction risk research and Red List assessment practice, increase the taxonomic coverage and consistency of assessments, and ensure the IUCN Red List is up-to-date to best support conservation policy and practice across the world.
This study investigated the effects of varied loadings of TiO2 overlayers in heterojunction with conventional Ir0.7Ta0.3Ox (IrTaOx) anodes on chlorine evolution reaction (ClER) and real (waste)water treatment at circum-neutral pH. With an optimized design of IrTaOx/TiO2, elevated ClER selectivity was attained by more facile chemisorption of chloride ions to a thin TiO2 layer on IrTaOx. The current efficiency (CE) of ClER in galvanostatic electrolysis of 50 mM NaCl solutions (at 30 mA cm(-2)) was maximized to similar to 80% by a heterojunction architecture with similar to 605 mu g cm(-2) of IrTaOx and similar to 265 mu g cm(-2) of TiO2 after specific rounds of drop casting. Further increases in loading resulted in escalated film-pore resistance or deterioration of ClER selectivity. The observed CE values were correlated with experimental descriptors, such as potential of zero charge and flat band potential, demonstrating that the weaker metal-oxygen bond strength on TiO2 could enhance the ClER selectivity compared to bare IrTaOx. We concluded that ClER primarily occurs on TiO2 near the junction owing to the nanoporous nature of the TiO2 layer, while IrTaOx serves as ohmic contact. The optimized IrTaOx/TiO2 anodes effectively improved the treatment of reverse osmosis concentrate, but phosphate ions in livestock wastewater caused adverse effects due to complexation on TiO2. The heterojunction architecture effectively tunes the surface charge density for selective generation of oxidants, which can facilitate electrochemical water treatment with reduced use of the precious metals.
Human-driven extinction threatens entire lineages across the Tree of Life. Here we assess the conservation status of jawed vertebrate evolutionary history, using three policy-relevant approaches. First, we calculate an index of threat to overall evolutionary history, showing that we expect to lose 86–150 billion years (11–19%) of jawed vertebrate evolutionary history over the next 50–500 years. Second, we rank jawed vertebrate species by their EDGE scores to identify the highest priorities for species-focused conservation of evolutionary history, finding that chondrichthyans, ray-finned fish and testudines rank highest of all jawed vertebrates. Third, we assess the conservation status of jawed vertebrate families. We found that species within monotypic families are more likely to be threatened and more likely to be in decline than other species. We provide a baseline for the status of families at risk of extinction to catalyse conservation action. This work continues a trend of highlighting neglected groups—such as testudines, crocodylians, amphibians and chondrichthyans—as conservation priorities from a phylogenetic perspective.
Wastewater electrolysis cells (WECs) for decentralized wastewater treatment/reuse coupled with H2 production can reduce the carbon footprint associated with transportation of water, waste, and energy carrier. This study reports Ir-doped NiFe2O4 (NFI, 5 at
An increasing number of countries in the Global North have enacted, or are considering, import bans on hunting trophies to protect wildlife. We interrogate arguments used to characterize trophy hunting using data from the Convention on International Trade in Endangered Species (CITES), the International Union for Conservation of Nature (IUCN) Red List of Threatened Species, and empirical research. We show that trophy hunting is not a major threat to any CITES-listed species traded as a trophy during 2000-2022. Yet, 60% of global trade in trophies involving these species may be impacted by bans, with significant implications for conservation. We therefore question whether such legislative actions are proportionate. Wildlife trade solutions may appear simple but evidence-based policy is needed to conserve biodiversity and avoid harming people. ### Competing Interest Statement DWSC is a member of the IUCN CEESP/SSC Sustainable Use and Livelihoods Specialist Group (SULi) and the IUCN SSC Pangolin Specialist Group. DM is Co-Chair of the IUCN SSC Antelope Specialist Group, a member of the Caprinae, Cat, and Equid Specialist Groups, and a member of SULi. MTSR is a member of the IUCN SSC African Rhino Specialist Group and SULi. AD conducted this work under a Fellowship funded by the Recanati-Kaplan Foundation and Panthera. She has consultancies with the Darwin Expert Committee and Jamma International, but neither funded this work. AD leads WildCRU which has funding from donors with a wide variety of views of trophy hunting. DH receives research funding from Jamma International, WWF Deutschland, and the Luc Hoffmann Institute (now Unearthodox), the Band Foundation, and the John Muir Trust. AGH is a member of SULi and has received non-personal funding from Jamma International, although not for this study. RM-C is employed as the Chief Ecologist Terrestrial with the Parks and Wildlife Management Authority in Zimbabwe. DR is the Chair of SULi which receives funding from Jamma International and the Abu Dhabi Environment Agency although neither funded this study, and is a member of the Darwin Expert Committee. JEB declares no conflicts of interest. MH is employed by ZSL and is a member of the IUCN SSC Afrotheria, Antelope, Bear, and Canid Specialist Groups, and SULi.
Robust species-level methods for quantifying ecological differences have yet to be incorporated into conservation strategies. Here, we describe a new approach to measure the unique contribution of species to overall functional diversity and incorporate it into an actionable conservation metric. The Functionally Distinct and Globally Endangered (FuDGE) metric directs conservation action to species whose extinction would result in significant losses of irreplaceable functional diversity. We apply FuDGE to the world’s sharks and compare it with the phylogeny-based Evolutionarily Distinct and Globally Endangered (EDGE) metric to highlight shared and divergent priorities for conservation. Identifying threatened species revealed that functionally distinct species are disproportionately threatened, with 17-24% of extant shark trait space at risk of extinction. We show that exploitation by humans threatens to disproportionately erode shark trait space, with 70% of trait space at risk. We hope our FuDGE metric will be used to guide the conservation of functionally irreplaceable species in the face of human impacts. ### Competing Interest Statement The authors have declared no competing interest.
The Kunming-Montreal Global Biodiversity Framework was adopted in December 2022 by the parties to the Convention on Biological Diversity. The framework states outcomes for species to be achieved by 2050 in goal A and establishes a range of targets to reduce pressures on biodiversity and halt biodiversity loss by 2030. Target 4 calls for urgent recovery actions for species where the implementation of other targets is insufficient to eliminate extinction risk. We analyze key species elements of goal A and target 4, examine their meaning and clarify implementation needs. We emphasize that target 4 should not be seen simply as the species target, because effective implementation of all targets is essential to achieve the species ambitions in goal A, but, rather, as a target for species that require urgent focused actions and emphasize that an indicator is needed to measure the implementation of urgent management actions. We conclude by considering next steps to identify priorities, undertake further research, make use of resources, ensure cooperation and capacity development.
Governments recently adopted new global targets to halt and reverse the loss of biodiversity. It is therefore crucial to understand the outcomes of conservation actions. We conducted a global meta-analysis of 186 studies (including 665 trials) that measured biodiversity over time and compared outcomes under conservation action with a suitable counterfactual of no action. We find that in two-thirds of cases, conservation either improved the state of biodiversity or at least slowed declines. Specifically, we find that interventions targeted at species and ecosystems, such as invasive species control, habitat loss reduction and restoration, protected areas, and sustainable management, are highly effective and have large effect sizes. This provides the strongest evidence to date that conservation actions are successful but require transformational scaling up to meet global targets.
Electrochemical oxidation provides a versatile technique for treating wastewater streams onsite. We previously reported that a two-layer heterojunction Ni-Sb-SnO2 anode (NAT/AT) can produce both ozone (O3) and hydroxyl radical (•OH). In this study, we explore further the applicability of NAT/AT anodes for oxidizing pharmaceutical compounds using carbamazepine (CBZ) and fluconazole (FCZ) as model probe compounds. Details of the oxidation reaction kinetics and subsequent reaction products are investigated in the absence and presence of chloride (Cl-) and sulfate (SO4 2-). In all cases, faster or comparable degradation kinetics of CBZ and FCZ are achieved using the double-layered NAT/AT anode coupled with a stainless steel (SS) cathode in direct comparison to an identical setup using a boron-doped diamond anode. Production of O3 on NAT/AT enhances the elimination of both parent compounds and their transformation products (TPs). Very fast CBZ degradation is observed during NAT/AT-SS electrolysis in both NaClO4 and NaCl electrolytes. However, more reaction products are identified in the presence of Cl- than ClO4 - (23 TPs vs 6). Rapid removal of FCZ is observed in NaClO4, while the degradation rate is retarded in NaCl depending on the [Cl-]. In SO4 2--containing electrolytes, altered reaction pathways and transformation product distributions are observed due to sulfate radical generation. SO4 ·- oxidation produces fewer hydroxylated products and promotes the oxidation of aldehydes to carboxylic acids. Similar trend in treatment performance is observed in mixtures of CBZ and FCZ with other pharmaceutical compounds in latrine wastewater and secondary WWTP effluent.
Despite being central to the implementation of conservation policies, the usefulness of the International Union for Conservation of Nature (IUCN) Red List of Threatened Species is hampered by the 14% of species classified as data-deficient (DD) because information to evaluate these species' extinction risk was lacking when they were last assessed or because assessors did not appropriately account for uncertainty. Robust methods are needed to identify which DD species are more likely to be reclassified in one of the data-sufficient IUCN Red List categories. We devised a reproducible method to help red-list assessors prioritize reassessment of DD species and tested it with 6887 DD species of mammals, reptiles, amphibians, fishes, and Odonata (dragonflies and damselflies). For each DD species in these groups, we calculated its probability of being classified in a data-sufficient category if reassessed today from covariates measuring available knowledge (e.g., number of occurrence records or published articles available), knowledge proxies (e.g., remoteness of the range), and species characteristics (e.g., nocturnality); calculated change in such probability since last assessment from the increase in available knowledge (e.g., new occurrence records); and determined whether the species might qualify as threatened based on recent rate of habitat loss determined from global land-cover maps. We identified 1907 species with a probability of being reassessed in a data-sufficient category of >0.5; 624 species for which this probability increased by >0.25 since last assessment; and 77 species that could be reassessed as near threatened or threatened based on habitat loss. Combining these 3 elements, our results provided a list of species likely to be data-sufficient such that the comprehensiveness and representativeness of the IUCN Red List can be improved.
The chlorine evolution reaction (CER) is a key reaction in electrochemical oxidation (EO) water treatment. Conventional anodes based on platinum group metals (PGMs) can be prohibitively expensive, which hinders the further application of EO systems. Crystalline cobalt antimonate (CoSb2O6) was recently identified as a promising alternative to conventional anodes due to its high catalytic activity and stability in acidic media. However, its catalytic sites and reaction mechanism have not yet been elucidated. This study sheds light on the catalytic active sites in crystalline CoSb2O6 anodes by using scanning electrochemical microscopy (SECM) to compare the CER catalytic activities of a series of anode samples with different Sb/Co ratios. The results showed that Sb sites served as more active catalytic sites than the Co sites. The varied Sb/Co ratios were also linked with slightly different electronic states of each element, leading to different CER selectivity in chloride solutions. The high activity of Sb sites towards CER highlighted the significance of the electronic polarization that changed the oxidation states of Co and Sb.
Nitrogen recovery from wastewater represents a sustainable route to recycle reactive nitrogen (Nr). It can reduce the demand of producing Nr from the energy-extensive Haber-Bosch process and lower the risk of causing eutrophication in the meantime. In this aspect, source-separated fresh urine is an ideal source for nitrogen recovery given its ubiquity and high nitrogen contents. However, current techniques for nitrogen recovery from fresh urine require high energy input and are of low efficiencies because the recovery target, urea, is a challenge to separate. In this work, we developed a novel fresh urine nitrogen recovery process with the assistance of modular functionalized metal-organic frameworks (MOFs). Specifically, we employed three distinct modification methods to design and synthesize functionalized MOF-808 derivatives to facilitate our newly developed Nr recovery process. By integrating these functional materials into the treatment process, we achieved an average of 75% total nitrogen reduction and 45% nitrogen recovery with five cycles, each with a 30 min treatment of synthetic fresh urine. The nitrogen recovery process developed in this work can serve as a sustainable and efficient nutrient management that is suitable for decentralized toilet wastewater treatment. This work also provides a new perspective of implementing versatile advanced materials for water and wastewater treatment.