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Freshwater habitats support high levels of biodiversity and provide important habitat for wetland‐dependent taxa; however, impairment of aquatic connectivity through wetland loss, stream alterations and light pollution impacts species persistence and community resilience. Quantifying occupancy of these habitats to assess their use by mammals and birds can be challenging, especially for cryptic species.This study examines wetland habitat use by mammals and birds, and their spatial and temporal relationships within the Beaver Hills Biosphere in Alberta, Canada. As part of a multi‐method detection approach, camera boxes, cameras on beaver dams, and camera rafts allowed for multivariate analyses to determine temporal and spatial patterns of habitat use and species associations, while field sampling and environmental DNA (eDNA) provided data on site occupancy by a subset of semi‐aquatic mammals.From ~50,000 images, over 84 species were detected, including 52 species of birds and 25 species of mammals. Several species were spatially associated, and although most species of mammals exhibited temporal overlap, there were distinct differences, especially on beaver dams where predators such as coyotes and white‐tailed deer shared the same space. Temporally, birds were detected most often during the day and mammals at night. During new moon phases, use of beaver dams by beavers decreased dramatically, and use of camera rafts by muskrats increased.Winter field surveys allowed for a broad overview of wetland occupancy and abundance of some species, particularly by beavers and muskrats, and occasionally winter use by other semi‐aquatic mammals. Where there was limited detection of more cryptic species of semi‐aquatic mammals, eDNA analysis successfully detected American water shrew, American mink, North American river otter and northern bog lemming more often than camera and field methods.Applying a multi‐method monitoring approach for mammals and birds in wetland habitats is critical at a time when freshwater systems are experiencing dramatic declines in relative abundance of monitored wildlife populations, with many of these species underrepresented in conventional surveys. [ABSTRACT FROM AUTHOR]

An overview of freshwater fish variety worldwide and the variables influencing trends in variation between and within river basins are given in this review. Continental freshwater ecosystems are highly diverse and species-rich, housing nearly 18,000 species of fish (>50% of all fish species) in <0.5% of the total land area and providing a negligible (<0.01%) share of the planet's water supply. Large lowland tropical river basins such as the Amazon, Congo, and Mekong basins are home to the greatest freshwater fish diversity. Freshwater species of fish depth variation at the global magnitude is correlated with the total amount and variation of aquatic habitats and the environment's equilibrium overtime during the evolution of scales. The river continuum concept states that there is a predictable shift in fish species depth, diversity of species, and functional characteristics along gradients of environment from headwater to estuary. The ongoing trade of minerals and organic matter related to nearby floodplains is a strong factor in the number and variety of riverine fishes in most parts of the world (the flood pulse concept). Without coordinated conservation efforts, freshwater fishes will suffer significant losses in abundance and diversity due to the numerous threats they currently face worldwide. However, further development, adaptation, training, and guidance are needed. New technologies based on water conservation, suitable species, and local traditions are needed. Waste materials and local feed additives can also be used. Farmers should be provided with the necessary training and information. [ABSTRACT FROM AUTHOR]

The Indo‐Burma biodiversity hotspot has one of the world's most species‐rich inland waters. However, its freshwater biodiversity faces habitat loss and species extinction due to large‐scale development of water resources, pollution, exploitation of native biota, and introduced non‐native species.These threats include the South American suckermouth armoured catfishes, Pterygoplichthys spp., that have invaded parts of this biodiversity hotspot. Pterygoplichthys spp. are among the most impactful introduced fishes globally and pose a 'very high risk' of becoming invasive once introduced.This paper aims to compile a distribution database for Pterygoplichthys spp., map their current global distribution, and estimate their potential distribution extent in the Indo‐Burma biodiversity hotspot using MaxEnt.In the Indo‐Burma region, Pterygoplichthys spp. have already been reported from China, Myanmar, Thailand and Vietnam, with populations also present in neighbouring India, Bangladesh, Malaysia, Singapore and Indonesia. No populations were verified for Cambodia and Laos.A maximum entropy model was developed based on the current global distribution of Pterygoplichthys spp. The species distribution model showed that the entire biodiversity hotspot, except the spine of the Arkan Mountains and the Hengduan Mountains from Three Gorges to the Hong River Valley, is suitable for Pterygoplichthys spp. An effective temperature of 15°C was identified as the lower limit of Pterygoplichthys spp. habitat suitability.Pterygoplichthys spp. were identified as a high‐risk taxon for freshwaters of almost the entire Indo‐Burma biodiversity hotspot. A coordinated management plan for Pterygoplichthys spp. is required to safeguard the freshwater biota of the Indo‐Burma freshwater ecosystems. [ABSTRACT FROM AUTHOR]

Freshwater wetlands are the wetland ecosystems surrounded by freshwater, which are at the interface of terrestrial and freshwater ecosystems, and are rich in ecological composition and function. Biodiversity in freshwater wetlands plays a key role in maintaining the stability of their habitat functions. Due to anthropogenic interference and global change, the biodiversity of freshwater wetlands decreases, which in turn destroys the habitat function of freshwater wetlands and leads to serious degradation of wetlands. An in-depth understanding of the effects of biodiversity on the stability of habitat function and its regulation in freshwater wetlands is crucial for wetland conservation. Therefore, this paper reviews the environmental drivers of habitat function stability in freshwater wetlands, explores the effects of plant diversity and microbial diversity on habitat function stability, reveals the impacts and mechanisms of habitat changes on biodiversity, and further proposes an outlook for freshwater wetland research. This paper provides an important reference for freshwater wetland conservation and its habitat function enhancement. [ABSTRACT FROM AUTHOR]

Urbanisation continues to increase at an alarming rate and its effects on the natural environment are very profound now more than ever. Moreover, studies on terrestrial urban landscapes seems to be more than that on urban freshwater habitats. Furthermore, studies have shown that the Odonata are effective indicators of the effects of urbanisation on freshwater habitats. However, not much is known about their responses to urbanisation in sub-Saharan Africa, especially given the unique set of conditions that characterise the area. Therefore, this study was conducted to investigate differences in Odonata responses, measured as the proportion of habitat generalists, to three levels of habitat disturbance in the Cape Coast Metropolis of Ghana. Results showed that Phaon camerunensis was a potential indicator of habitat disturbance. Also, differences in habitat disturbance significantly affected Odonata composition. The most important variables that influenced Odonata responses were the individual and interaction effects of altitude and preservation of riparian vegetation. Therefore, conservation strategies that are targeted at reducing the impacts of urbanisation on Odonata must focus on these variables. [ABSTRACT FROM AUTHOR]

Aim: Human activities have introduced numerous non‐native species (NNS) worldwide. Understanding and predicting large‐scale NNS establishment patterns remain fundamental scientific challenges. Here, we evaluate if NNS composition represents a proportional subset of the total species pool available to invade (i.e. total global biodiversity), or, conversely, certain taxa are disproportionately pre‐disposed to establish in non‐native areas. Location: Global. Time period: Present day. Major taxa studied: Global diversity. Methods: We compiled one of the most comprehensive global databases of NNS (36,822 established species) to determine if NNS diversity is a representative proportional subset of global biodiversity. Results: Our study revealed that, while NNS diversity mirrors global biodiversity to a certain extent, due to significant deviance from the null model it is not always a representative proportional subset of global biodiversity. The strength of global biodiversity as a predictor depended on the taxonomic scale, with successive lower taxonomic levels less predictive than the one above it. Consequently, on average, 58%, 42% and 28% of variability in NNS numbers were explained by global biodiversity for phylum, class and family respectively. Moreover, global biodiversity was a similarly strong explanatory variable for NNS diversity among regions, but not habitats (i.e. terrestrial, freshwater and marine), where it better predicted NNS diversity for terrestrial than for freshwater and marine habitats. Freshwater and marine habitats were also greatly understudied relative to invasions in the terrestrial habitats. Over‐represented NNS relative to global biodiversity tended to be those intentionally introduced and/or 'hitchhikers' associated with deliberate introductions. Finally, randomness is likely an important factor in the establishment success of NNS. Main conclusions: Besides global biodiversity, other important explanatory variables for large‐scale patterns of NNS diversity likely include propagule and colonization pressures, environmental similarity between native and non‐native regions, biased selection of intentionally introduced species and disparate research efforts of habitats and taxa. [ABSTRACT FROM AUTHOR]

During the survey on freshwater hyphomycetes in Guangxi, Guizhou and Hainan Provinces, China, five fresh collections were encountered. Based on their morphology, these five isolates were identified as belonging to Hermatomyces, Kirschsteiniothelia, Paramonodictys, Pleopunctum and Sparticola. Multigene phylogenetic analyses were performed for each genus, which resulted in the identification of five new species, namely Hermatomyces hainanensis, Kirschsteiniothelia ramus, Paramonodictys globosa, Pleopunctum guizhouense, and Sparticola irregularis. Detailed descriptions and illustrations of the morphological characteristics of these new taxa were provided. This research enriches the biodiversity of freshwater dematiaceous hyphomycetes. [ABSTRACT FROM AUTHOR]

Context: The ability to accurately assess biodiversity is a critical first step towards effective conservation and management. However, assessment of biodiversity using conventional monitoring programs is often constrained by high cost and a lack of taxonomic expertise. Environmental DNA (eDNA) metabarcoding may be a useful tool to efficiently catalogue biodiversity in areas that cannot be easily assessed using other methods. Aims: Here, we evaluated the potential of eDNA metabarcoding for assessing fish biodiversity and distribution in the Kumbe River, Papua Province, Indonesia. Methods: We selected four sampling locations and collected seven eDNA samples from each location. We used eDNA metabarcoding of the Cytochrome- b gene to characterise the fish community. Key results: A total of 23 species were detected, three of which comprised 92% of sequence reads detected: Melanotaenia goldiei (32%), Craterocephalus randi (31%), and the invasive tilapia Oreochromis niloticus (29%). Only five species that were previously detected using conventional methods were detected by metabarcoding: M. goldiei , Craterocephalus stercusmuscarum , O. niloticus , Neoarius graeffei , and Arius arius. We detected 18 species (70% native) that have never been recorded from the Kumbe River. Conclusions: This work has demonstrated that fish biodiversity is substantially underestimated in the Kumbe River. Environmental DNA metabarcoding is a promising rapid, non-invasive and cost-effective method for assessing fish biodiversity in Papua. Implications: The findings support future investment in eDNA metabarcoding to characterise the fish biodiversity in Papua. This will assist in allocating the limited resources for conservation and management to areas most at risk from anthropogenic impacts. Environmental DNA (eDNA) metabarcoding shows great promise as a novel tool for fish biomonitoring programs in tropical freshwater habitats. It is sensitive, non-invasive and cost-effective. However, our results highlight that eDNA metabarcoding cannot be routinely applied without further research into sampling design, marker choice, seasonal data, and an improved reference database to reduce false negative detections. Despite this, eDNA metabarcoding will play an important role in the future characterisation of the fish community in tropical river systems. [ABSTRACT FROM AUTHOR]

Myxozoans are a unique group of microscopic parasites that infect mainly fishes. These extremely reduced cnidarians are highly diverse and globally distributed in freshwater and marine habitats. Myxozoan diversity dimension is unknown in Mexico, a territory of an extraordinary biological diversity. This study aimed to explore, for the first time, myxozoan parasite diversity from fishes of the Neotropical region of Mexico. We performed a large morphological and molecular screening using host tissues of 22 ornamental and food fish species captured from different localities of Veracruz, Oaxaca and Chiapas. Myxozoan infections were detected in 90% of the fish species, 65% of them had 1 or 2 and 35% had 3 and up to 8 myxozoan species. Forty-one putative new species were identified using SSU rDNA phylogenetic analyses, belonging to two main lineages: polychaete-infecting (5 species) and oligochaete-infecting (36 species) myxozoans; from those we describe 4 new species: Myxidium zapotecus sp. n., Zschokkella guelaguetza sp. n., Ellipsomyxa papantla sp. n. and Myxobolus zoqueus sp. n. Myxozoan detection increased up to 6 × using molecular screening, which represents 3.7 × more species detected than by microscopy. This study demonstrated that Neotropical fishes from Mexico are hosts of a multitude of myxozoans, representing a source of emerging diseases with large implications for economic and conservation reasons. [ABSTRACT FROM AUTHOR]

The River Indus is one of the most extended water bodies in Pakistan. It is a source of drinking water, hydroelectric power generation, irrigation, agriculture and aquaculture. The present examination wanted to survey the river's physicochemical parameters and biodiversity from June 2016 to May 2017. Total eight stations have been selected along the Indus River, and 08 water quality parameters, i.e., temperature, salinity, dissolved oxygen, power of hydrogen, transparency, alkalinity, hardness, and total dissolved solids, have been checked from all stations on the spot and bring water samples in a plastic bottle. Fish samples were also collected from all stations, preserved all the samples in 10% formalin, and further investigated in the Fresh Water Biology Laboratory at the University of Sindh Jamshoro. A total of 45 fish species have been identified throughout the study period. [ABSTRACT FROM AUTHOR]

Plastic production has inevitably increased in the past few decades and is one of today's most diverse materials. With this growing production and broader use, aquatic ecosystems have become the trash barrel for all kinds of plastic, becoming a looming spectre to the habitat and functions of both inland and offshore ecosystems. Microplastics are a pollutant of growing concern, capable of harming aquatic organisms and entering the food web. While, freshwater microplastic research has expanded in recent years, much remains to be discovered regarding microplastic sources and delivery pathways in these environments. Plastic pollution is considered an emerging global environmental concern that could significantly affect biological diversity and potentially cause adverse effects on human health. Compared to the studies on microplastics in marine ecosystems, the studies on their presence in freshwater ecosystems have received relatively less attention. This review article focuses on the literature available on reports of microplastic occurrence, its distribution in freshwater ecosystems worldwide, and its insidious effects, which are of emerging concern. [ABSTRACT FROM AUTHOR]

The ecological significance of freshwater ecosystems for conservation in the temperate zone has been determined by aquatic biologists using a variety of ecological techniques. One such tool is the Community Conservation Index (CCI), which was primarily developed in Britain but is also recommended for international use. The current study intends to further test the CCI's applicability and its sensitivity in identifying freshwater systems of high conservation importance. The pristine condition of three natural monument (Arinta, Ekor, and Oowu waterfalls) streams was evaluated in this study using the macroinvertebrate metric indicators, and the results were compared with their CCIs. The relative compositions of stress-sensitive species, facultative species, functional feeding guilds (FFGs), and modes of locomotion or microhabitat preference (ML/MP) were selected as the macroinvertebrate metrics. The fauna was dominated by the taxonomic group EPT (Ephemeroptera, Plecoptera, Trichoptera), with the highest EPT-related metrics found at Oowu Waterfalls. Ironically, because a vulnerable species (i.e. Pentaphlebia stahli) is present there, the Ekor Waterfalls, which had the lowest values for the EPT-related metrics, had the highest CCI. Although both the CCI (>20) and macroinvertebrate metrics suggest that the three sites had high conservation value, the CCI proved to be more goal-oriented in determining the conservation value of pristine freshwater ecosystems. In light of the findings of this study, it is recommended that the CCI be utilized in conjunction with macroinvertebrate metric indicators for studies of a similar nature, particularly in Afrotropics' protected and pristine sites that are a potential refuge for rare and threatened species. [ABSTRACT FROM AUTHOR]

Background: Freshwater fungi refer to the fungi that depend on the freshwater habitats for the whole life cycle or part of their life cycle. In this context, a new aquatic hyphomycete was isolated from decaying wood in a freshwater habitat in Jiangxi Province, China. New information: Dictyochaeta jiangxiensis sp. nov., a new aquatic hyphomycete, is characterised by its unbranched, septate, base-fertile conidiophores with multisepta and single phialide at the apex, brown, sterile seta, monophialidic, subcylindrical conidiogenous cells narrowing below the funnel-shaped collarette, hyaline, unicellular, thin-walled, smooth, guttulate, falcate to subclavate conidia narrowly rounded at both ends with hair-like appendages. Phylogenetically, the new species Dictyochaeta jiangxiensis clustered together with Dictyochaeta brevis MFLU 19-0216 in a well-supported clade, but formed a separate branch. In order to better define the taxonomic status of the new species, a phylogenetic tree of most closely-related taxa in Chaetosphaeriaceae was established, based on multilocus sequences (ITS and LSU). The novel species is described and illustrated. Newlygenerated molecular data of Dictyochaeta jiangxiensis is also provided. [ABSTRACT FROM AUTHOR]

We outline a 100% georeferenced dataset of aquatic macroinvertebrate occurrence records collected from the operational area of the Körös-Maros National Park Directorate (SE Hungary) between 2012 and 2021. The species-level dataset includes 25,935 records of 644 taxa from 625 localities of wide variety of freshwater habitats from soda pans to lowland marshes and small watercourses to medium-sized and larger rivers. Four non-biting midge species are reported for the first time from the Hungarian fauna. The dataset is available through the Global Biodiversity Information Facility (GBIF). [ABSTRACT FROM AUTHOR]

A Sardinian small trebouxiophycean alga, Laetitia sardoa, is described as a novel species and genus. This green alga was collected in an oligotrophic freshwater habitat, and its morphology was investigated. The strain established belongs to the order Chlorellales, of the class Trebouxiophyceae, as inferred from phylogenetic analyses of nuclear-encoded 18S rDNA and chloroplast-encoded ribulose-bisphosphate carboxylase-oxydase gene (rbcL). The analyses supported Laetitia as a distinct lineage, sister to a Marvania clade. The taxonomy of this order has long been problematic due to the lack of distinguishable morphological characteristics. With the characterization of this microalgal strain, we confirmed the necessity of using molecular analyses to determine these cryptic algae. Moreover, our study contributes to the knowledge of the taxonomy and ecology of Chlorellales (Chlorophyta). In addition, the discovery of this new genus in the Ogliastra's Tacchi suggests the potential diversity of this area, which up to now has remained largely unknown, and increases the general knowledge of the microalgal flora of this region. [ABSTRACT FROM AUTHOR]

Many biodiversity studies focus on explaining high tropical species richness, but an equally dramatic yet understudied pattern involves the divergent richness of land, sea and freshwater. Here, we reveal the origins of these richness differences among habitats across animals and plants. Most plant and animal species are terrestrial, although these habitats cover only ~28% of Earth's surface. Marine habitats have fewer species over a larger area (~70%). Freshwater habitats have relatively high richness and exceptional phylogenetic diversity given their tiny area (2%). The relative richness of habitats is related to variation in diversification rates. Based on ancestral reconstructions of habitat, we find that most marine species are descended from marine ancestors and most terrestrial species from freshwater ancestors. Yet, most extant animal richness in freshwater is derived from terrestrial ancestors. Overall, our results reveal the origins of fundamental but neglected biodiversity patterns, and highlight the conservation importance of freshwater habitats. [ABSTRACT FROM AUTHOR]

Mountain lakes are unique and often isolated freshwater habitats that harbour a rich biotic diversity. This high conservation value may be reflected by diatoms, a group of algae that is known for its reliability as a bioindicator, but which has not been studied extensively in mountain lakes of the northern European Alps. In this study, the conservation value of these lakes was assessed by characterizing the number, share, and abundance of diatom Red List (RL) taxa and their relationship with environmental variables, diatom α and β diversity (assemblage uniqueness). For this purpose, linear regression models, generalized linear models, and generalized additive models were fitted and spatial descriptors were included when relevant. Of the 560 diatom taxa identified, 64% were on the RL and half of these were assigned a threat status. As hypothesized, a decreasing share of RL species in sediment and littoral samples at higher trophic levels was reflected by higher total phosphorous content and lower Secchi depth, respectively. Species-rich lakes contained a high number of RL taxa, contrasting our hypothesis of a logarithmic relationship. In turn, RL abundance increased with uniqueness, confirming our initial hypothesis. However, some of the most unique sites were degraded by fish stocking and contained low abundances of RL species. The results demonstrate the importance of oligotrophic mountain lakes as habitats for rare freshwater biota and their vulnerability in light of human impact through cattle herding, tourism, damming, and fish stocking. Additional conservation efforts are urgently needed for mountain lakes that are still underrepresented within legal conservation frameworks. Species richness and uniqueness reflect complementary aspects of RL status and thus should be applied jointly. Uniqueness can indicate both pristine and degraded habitats, so that including information on human impacts facilitates its interpretation. [ABSTRACT FROM AUTHOR]

Foraminifera include diverse shell‐building lineages found in a wide array of aquatic habitats from the deep‐sea to intertidal zones to brackish and freshwater ecosystems. Recent estimates of morphological and molecular foraminifera diversity have increased the knowledge of foraminiferal diversity, which is critical as these lineages are used as bioindicators of past and present environmental perturbation. However, a comparative analysis of foraminiferal biodiversity between their major habitats (freshwater, brackish, intertidal, and marine) is underexplored, particularly using molecular tools. Here, we present a metabarcoding survey of foraminiferal diversity across different ecosystems using newly designed foraminifera‐specific primers that target the hypervariable regions of the foraminifera SSU‐rRNA gene (~250–300 bp long). We tested these primer sets on four foraminifera species and then across several environments: the intertidal zone, coastal ecosystems, and freshwater vernal pools. We retrieved 655 operational taxonomic units (OTUs); the majority of which are undetermined taxa that have no closely matching sequences in the reference database. Furthermore, we identified 163 OTUs with distinct habitat preferences. Most of the observed OTUs belonged to lineages of single‐chambered foraminifera, including poorly explored freshwater foraminifera which encompass a clade of Reticulomyxa‐like forms. Our pilot study provides the community with an additional set of newly designed and taxon‐specific primers to elucidate foraminiferal diversity across different habitats. [ABSTRACT FROM AUTHOR]

The island of Penang lying off the northwestern coast of Peninsular Malaysia, is one of the historical places for ichthyological exploration in Southeast Asia and the type locality of three freshwater species and one euryhaline species. Freshwater ecosystems on the island are currently threatened by multiple causes. To facilitate further environmental-oriented monitoring actions, we reexamined the fish diversity by surveying several freshwater localities across the island. All collected specimens were vouchered, morphologically identified and then genetically characterized using the "Barcode" fragment of the cytochrome oxidase I gene. We collected a total of 52 fish species, including 37 (21 native + 16 introduced) strictly-adapted freshwater species. Five native and 10 introduced species represent new records for the island. Genetic analyses revealed low cryptic diversity within morphologically identified species. Combining our results with those of previous surveys, a total of 63 fish species are now known from Penang freshwaters, however, five native species were not collected in the last 60 years and their conservation status is certainly at risk on the island. Overall, the presence of many introduced species along with the general degradation of freshwater habitats of Penang Island threaten its native fish diversity. [ABSTRACT FROM AUTHOR]

In this study, we present a new method to compare the distribution of knowledge regarding the biodiversity of a taxa with the distribution of environments inhabited by that taxa, in order to identify the main geographical gaps in biodiversity knowledge. We compared the geographical distribution of studies describing freshwater fish assemblages in Argentina with the distribution of freshwater bodies, delimiting priority areas that require additional sampling effort in order to achieve a more balanced understanding of this taxa's diversity throughout the country. Our results show a substantial geographical bias in the distribution of knowledge regarding freshwater fish assemblages in Argentina, with most of the studies concentrating on a few areas of the country. Many sectors appear as undersampled, and most of the country has been studied only recently, after many sites have undergone severe impact by anthropic activities. The absence of fish assemblages descriptions previous to habitat changes in these sites considerably limits our capacity to understand changes in biodiversity that anthropic habitat modifications might have generated or even the ones they are generating now. We show the areas of Argentina where freshwater fish diversity needs to be studied most urgently based on the distribution of freshwater habitats. [ABSTRACT FROM AUTHOR]

The noble crayfish (Astacus astacus), a keystone species of high ecological, economic, and cultural importance in Europe, is threatened due to a long-term population decline caused by anthropogenic pressure on its habitats, the presence of non-indigenous invasive crayfish species and climate change. Since the effective protection of the remaining populations requires conservation measures based on the comprehensive knowledge of the species, including good understanding of its genetic and morphological variability, our aim was to study morphological features of the noble crayfish in Croatia using geometric morphometrics for the first time. We applied two-dimensional geometric morphometrics to find morphological differences among 15 populations of the noble crayfish from Croatian freshwater habitats, grouped according to previously established (a) mitochondrial (genetic) lineages, (b) genetic clusters inferred from nuclear microsatellites, as well as (c) river basins and (d) habitat types (lotic, lentic). Overall, the results indicated the existence of morphological diversity among the studied populations of the noble crayfish in Croatia. Shape analysis showed differences in cephalon based on crayfish affiliation to different genetic lineages, genetic clusters, river basins and habitat types. Our study provided novel insights into morphological diversity of the endangered noble crayfish in the area of its high genetic diversity. [ABSTRACT FROM AUTHOR]

Anthropogenic climate change is increasingly threatening biodiversity on a global scale. Rich spots of biodiversity, regions with exceptionally high endemism and/or number of species, are a top priority for nature conservation. Terrestrial studies have hypothesized that rich spots occur in places where long-term climate change was dampened relative to other regions. Here we tested whether biodiversity rich spots are likely to provide refugia for organisms during anthropogenic climate change. We assessed the spatial distribution of both historic (absolute temperature change and climate change velocities) and projected climate change in terrestrial, freshwater, and marine rich spots. Our analyses confirm the general consensus that global warming will impact almost all rich spots of all three realms and suggest that their characteristic biota is expected to witness similar forcing to other areas, including range shifts and elevated risk of extinction. Marine rich spots seem to be particularly sensitive to global warming: they have warmed more, have higher climate velocities, and are projected to experience higher future warming than non-rich-spot areas. However, our results also suggest that terrestrial and freshwater rich spots will be somewhat less affected than other areas. These findings emphasize the urgency of protecting a comprehensive and representative network of biodiversity-rich areas that accommodate species range shifts under climate change. [ABSTRACT FROM AUTHOR]

Urbanisation is increasing globally, degrading terrestrial and freshwater habitats and reducing faunal and floral richness. Whilst the potential for garden ponds to serve as important biodiversity resources in urban areas has been documented in a limited number of studies, quantifying the contribution of garden ponds to urban freshwater diversity has been largely neglected. This study aims to quantify the taxonomic richness, community composition and conservation value of aquatic macroinvertebrates in domestic garden and non-urban ponds. Taxonomic richness was significantly lower in garden ponds than non-urban ponds at an alpha and gamma scale. A greater richness of Odonata, Coleoptera, Gastropoda and Hemiptera were recorded in non-urban ponds. Garden ponds were found to support compositionally different macroinvertebrate communities compared to non-urban ponds, influenced by variation in water depth and conductivity. A total of 23 taxa were recorded from garden ponds only. Non-urban ponds had a significantly higher conservation value compared to garden ponds (87% of garden ponds were of low or moderate conservation value, while only 35% of non-urban ponds were in these categories). Although garden ponds currently support limited macroinvertebrate diversity and have lower conservation value, they contribute to the regional species pool and their potential to limit future urban biodiversity loss is significant. Given their high abundance and popularity within the urban landscape, clear guidance is required for pond-owners on how to best manage garden ponds to support and sustain biodiversity. For this to be achieved, research is required to increase fundamental understanding of urban pond ecology, and the development of evidence led garden pond management practices. [ABSTRACT FROM AUTHOR]

Freshwater ecosystems have a higher percentage of threatened and extinct species than terrestrial or marine realms, but remain under‐represented in conservation research and actions arguably as a consequence of less popularity and promotion.Cover images of conservation journals were used as a proxy of exposure and potential promotion opportunities provided for different ecosystems and species. To examine whether articles related to cover images received more attention, citations and Altmetric scores of cover‐featured articles were compared with non‐featured ones within the same host journal issue.Freshwater ecosystems (10.4%) were featured less often than marine (15.2%) or terrestrial (74.4%) ecosystems on covers of 18 conservation journals from 1997 to 2016. All 15 most featured species are from terrestrial or marine ecosystems.In addition, cover‐featured studies showed higher citations and Altmetric scores than non‐featured ones within the same host journal issue, indicating that cover‐featured articles received more attention. Further investigations are needed to examine the relationship (i.e. whether there is a true causality) between being featured on the cover, and citations and Altmetric scores received by articles, as well as potentially resulting in greater conservation efforts. Nevertheless, we believe that providing exposure opportunities is likely to better inform the public about the continuing degradation of freshwater ecosystems and its impacts on human well‐being, including economic loss and danger to public health. Journal editors can contribute by balancing their selection of featured ecosystems and species when opportunities arise.Increasing exposure opportunities for freshwater ecosystems through various channels seems a promising approach to raise public awareness and appreciation of freshwater biodiversity. Scientists can play an active role and form an alliance with journal editors, conservation organizations, and media, to increase momentum in society for fresh waters to be experienced as essential ecosystems and prevent further degradation of freshwater habitats and biodiversity loss. [ABSTRACT FROM AUTHOR]

Ponds are among the most biodiverse and ecologically important freshwater habitats globally and may provide a significant opportunity to mitigate anthropogenic pressures and reverse the decline of aquatic biodiversity. Ponds also provide important contributions to society through the provision of ecosystem services. Despite the ecological and societal importance of ponds, freshwater research, policy, and conservation have historically focused on larger water bodies, with significant gaps remaining in our understanding and conservation of pond ecosystems. In May 2019, pond researchers and practitioners participated in a workshop to tackle several pond ecology, conservation, and management issues. Nine research themes and 30 research questions were identified during and following the workshop to address knowledge gaps around: (1) pond habitat definition; (2) global and long‐term data availability; (3) anthropogenic stressors; (4) aquatic–terrestrial interactions; (5) succession and disturbance; (6) freshwater connectivity; (7) pond monitoring and technological advances; (8) socio‐economic factors; and (9) conservation, management, and policy. Key areas for the future inclusion of ponds in environmental and conservation policy were also discussed. Addressing gaps in our fundamental understanding of pond ecosystems will facilitate more effective research‐led conservation and management of pondscapes, their inclusion in environmental policy, support the sustainability of ecosystem services, and help address many of the global threats driving the decline in freshwater biodiversity. [ABSTRACT FROM AUTHOR]

• Mountainous areas are attractive for human colonization. • In South Africa, mountains host high levels of aquatic arthropod endemism. • There are often trade-offs between urbanization and biodiversity conservation. • Urbanization presents several novel threats to freshwater conservation. • Threats can and have been mitigated to encourage arthropods in urban spaces. Mountains supply essential resources, making them attractive areas for human settlement. Variation in elevation in mountainous areas determines local and regional climates, leading to complex biodiversity patterns. Mountains in the Cape Floristic Region have high species richness and beta diversity, and very high levels of local endemism. Table Mountain is an iconic mountain in the region, and unusual, as it is in the centre of the city of Cape Town. It is exceedingly rich in biodiversity, including many localized endemic species. However, increasing urbanization in the area is adversely affecting the local biodiversity, especially in the lowlands. Climate change effects to date are minimal, but projected to interact with the impacts of urbanization. Here we review the biodiversity patterns of green and blue spaces in and around Cape Town, including Table Mountain, focusing on aquatic arthropods. We also review the major threats that lead to biotic impoverishment, and provide information on current conservation efforts aimed at protecting the rich biodiversity of Table Mountain and its surrounds. Finally, we focus on the shortcomings of existing conservation actions, and then provide conservation strategies to limit aquatic arthropod biodiversity losses, based on actions that have already worked well. To ensure protection of all arthropods, freshwater habitats across all elevations require further conservation action. Education and creating awareness must continue to close the gaps between scientists, conservation practitioners and civil society as a crucial part of the conservation plan. [ABSTRACT FROM AUTHOR]

In many biomes, a variety of different small freshwater habitats, such as pools and phytotelmata can occur together in the same habitat matrix. However, both the biodiversity and the functioning of these ecosystems remain poorly known.Three freshwater habitat types in a tropical West African biodiversity hotspot were studied.The study demonstrated that animal communities in water‐filled tree holes, temporary ponds and granite rock pools were strongly differentiated with exclusive faunas despite their spatial proximity and similar disturbance in the form of seasonal drought.In particular, granite rock pools stood out with a high gamma diversity. Rock pools were also functionally different from the other two habitat types. The three habitats had contrasting predator assemblages, a differential reliance on primary production and different concentrations of available nutrients.The work illustrates that the biodiversity and functions of small temporary freshwater habitats can be strongly differentiated. This shows the unique and potentially complementary roles that these habitats can fulfil in mediating fluxes of energy and nutrients and preserving aquatic biodiversity in landscapes.Temporary aquatic habitats are typically overlooked in conservation policy and local management plans despite being threatened by habitat transformation. In addition, livestock can threaten savanna ponds, wood exploitation can threaten tree holes, and mining and sediment disruption can threaten rock pools. Hence, better knowledge about the ecological functioning of these ecosystems is vital to the implementation of effective conservation strategies. [ABSTRACT FROM AUTHOR]

The Birds and Habitats Directive are the cornerstones of Europe's nature conservation policy and the resulting Natura 2000 (N2k) sites form the largest coordinated network of protected areas in the world. Despite the ambitious targets of these directives and decades of efforts, biodiversity, especially of freshwater-related species, continues to decline in Europe. While multiple stressors at larger spatial scales are known to limit the effect of river restoration projects, the importance of surrounding land use outside the N2k sites for freshwater-related species richness inside N2k sites has rarely been studied. Conditional inference forests were used to assess the importance of land use in the surrounding and upstream of the German N2k sites compared to local habitat conditions inside. Freshwater-related species richness depended on land use in the surrounding besides local habitat conditions. Results indicated that this was especially true for birds in small N2k sites embedded in a wet, diverse, and patchy landscape and for non-birds due to the provision of additional habitats outside the N2k sites. Given that most N2k sites in Europe are rather small, the surrounding habitat conditions and land use potentially influences and affects freshwater-related species in many N2k sites across Europe. The additional conservation and restoration areas to be designated under the EU Biodiversity Strategy and upcoming EU restoration law should either be large enough or surrounded by extensive land use to optimize their effect on freshwater-related species. • Freshwater-related species richness in German Natura 2000 sites was investigated. • Importance of surrounding land use and local habitat conditions were compared. • Species richness strongly depends on surrounding land use providing habitat. • Surrounding landuse is more important for more mobile birds compared to non-birds. • Surrounding landuse is more important in small Natura 2000 sites. [ABSTRACT FROM AUTHOR]

Freshwater ecosystems harbour a disproportionately high biodiversity relative to their area, being also one of the most threatened ecosystem types worldwide. However, our capacity to design evidence-based conservation plans for this realm is restricted by all biodiversity shortfalls that have been recognized so far. In this context, the paucity of comparable field data and information on traits and phylogenies of freshwater organisms should be emphasized. Here, we highlight how increased knowledge could be gained and where we should aim at in research on the functional and phylogenetic features of freshwater communities. First, attempts to combine datasets from different sources should pay careful attention to data harmonization. Second, more effort should be focused on natural history observations on species habitats and life histories, providing the backbone of information for multi-trait databases. Third, fully resolved phylogenies would be required for deciphering the evolutionary relationships of freshwater organisms. Provided that these three hurdles can be overcome, conducting studies of local freshwater communities across continental spatial extents would pave the way for mapping functionally important ecosystems and evolutionarily valuable areas for the conservation of freshwater organisms and their habitats. • Paucity of comparable field data and information on traits and phylogenies of freshwater organisms should be emphasized. • Combining datasets from different sources should pay careful attention to data harmonization. • More effort should be focused on observations on species habitats and life histories. • Fully resolved phylogenies are required for deciphering the evolutionary relationships of freshwater organisms. • These data would allow for mapping functionally important ecosystems and evolutionarily valuable areas for the conservation of freshwaters [ABSTRACT FROM AUTHOR]

Metal contamination is a global issue impacting biodiversity in urbanised estuaries. Traditional methods to assess biodiversity are time consuming, costly and often exclude small or cryptic organisms due to difficulties with morphological identification. Metabarcoding approaches have been increasingly recognised for their utility in monitoring, however studies have focused on freshwater and marine systems despite the ecological significance of estuaries. We targeted estuarine eukaryote communities within the sediments of Australia's largest urbanised estuary, where a history of industrial activity has resulted in a metal contamination gradient. We identified specific eukaryote families with significant correlations with bioavailable metal concentrations, indicating sensitivity or tolerance to specific metals. While polychaete families Terebellidae and Syllidae demonstrated tolerance to the contamination gradient, members of the meio- and microfaunal communities including diatoms, dinoflagellates and nematodes displayed sensitivities. These may have high value as indicators but are frequently missed in traditional surveys due to sampling limitations. • We sampled a metal contamination gradient in Australia's largest estuary. • We used eDNA metabarcoding to investigate benthic eukaryote communities. • Polychaete families displayed tolerance to bioavailable metal concentrations. • We found sensitivities of members of the meio- and microfaunal communities. • Metabarcoding offers a promising alternative to traditional monitoring approaches. [ABSTRACT FROM AUTHOR]

Habitat banking, a conservation approach to offset habitat loss, has been widely accepted and implemented in the United States, especially for the protection of freshwater ecosystems. The potential adequacy of the habitat banking approach has, however, not yet been formally quantified in the context of its underlying framework and policies. Using a gap analysis approach, we test the current adequacy and future potential of habitat banking for 2313 approved and 552 pending banks in the United States. In the analysis, we consider water stress due to projected climate change, freshwater diversity, imperiled species, and human population growth, among other factors. The results show that the highest conservation urgency was assigned to states in the Southwest with high levels of species imperilment and large increases in anticipated water stress. The banking network covers most of the freshwater biodiversity hotspots in the East and Southeast. Land ownership is a potential driver for the low bank density in western states, with large proportions of land being owned and managed through federal agencies and only 58 banks situated on federal land. While the banking network in the United States is one of the most developed on a global level, gaps and priority areas can be clearly identified to strengthen the current network and its role in preserving freshwater habitat and diversity. [Display omitted] • Habitat banking network in the United States covers freshwater biodiversity hotspots. • High environmental urgency and anticipated water stress in the Southwest • The Southwest lacks habitat banks in terms of number, density, and service area. • Only 2 % of habitat banks are on federal land. [ABSTRACT FROM AUTHOR]

Russian High Arctic archipelagos still lack knowledge on the freshwater ecosystems and biodiversity. Here, we present results of the freshwater bodies' survey of the nine islands in the Franz Josef Land archipelago, north-eastern Barents Sea, carried out in August 2016. Freshwater lakes and streams along with associated coastal habitats were examined for hydrochemistry, elemental composition of sediments, microbiota, macrozoobenthos, flora and vegetation as well as ornithofauna. Despite the harsh climate conditions and ephemeral character of the freshwater bodies, there were a diverse microflora and macrozoobenthos. Macrozoobenthos consisted primarily of chironomid larvae (with highest abundances at 6644.4 specimens/m2 and wet biomass hereinafter referred biomass 3.1 g/m2) and enchytraeids (abundances up to 922.2 specimens/m2, biomass up to 0.2 g/m2); additionally, numerous mermitides were found in two sites; and tardigrades were found in a single water body. Grass-moss and moss communities in coastal habitats were described. We propose to include freshwater bodies of Franz Josef Land in the CBMP network, which at the moment lacks any monitoring sites in the Russian High Arctic, and has the only site at comparable latitudes in the Arctic Canada. Our results can be used as the background data on the freshwater environment and biodiversity for - further monitoring. [ABSTRACT FROM AUTHOR]

Simple Summary: Increased public awareness of wetlands and the importance of their conservation stipulated various preservation or improvement projects. In 2012, riverine wetlands were created in the Nakdong River in Korea to replace those damaged or destroyed by the River Refurbishment Project, but they could not be maintained as functional wetlands, owing to the long-term neglect and lack of management. A previous survey detected various problems in these wetlands, including insufficient in/outflow function, shore instability, and difficulty in introducing appropriate water sources, which cause nutrient accumulation and algal blooms. The in/outflow functions of the mainstream and tributaries were hampered by soil and plant deposition. These chemical changes influenced the community composition of rotifers. In particular, three rotifer species—Brachionus, Keratella, and Trichocerca—were mainly distributed in wetlands with relatively high nutrient concentrations (total nitrogen and phosphorus). Therefore, the rotifer community can be used as an indicator of the nutritional status of a wetland, and the functional state of the wetland can be understood through continuous monitoring of rotifers. Hydrological characteristics of freshwater ecosystems are powerful determinants of the distribution of biological communities and changes in environmental factors. This study identified relationships between the wetland environment, rotifer community, and hydrological factors for 48 wetlands, to determine their impact on wetland conservation and management. Different hydrological factors produced different wetland environments, which influenced the rotifer community composition. The wetlands with "poor" "in/outflow function" and "shore stability" levels showed high conductivity, turbidity, depth, and concentrations of total nitrogen, total phosphorus, and chlorophyll a. In contrast, the dissolved oxygen levels and velocity were the highest in wetlands with "good" in/outflow function and shore stability variables. The nutritional status of each wetland affected the composition of the rotifer community. Some genera (Keratella, Brachionus, Anuraeopsis, Trichocerca, and Philodina) were found in wetlands with high concentrations of total nitrogen, total phosphorus, and chlorophyll a, and high turbidity and depth. In contrast, Ascomorpha and Ploesoma were found in wetlands with high dissolved oxygen levels and flow velocity. High densities of Lepadella, Lecane, and Testudinella were found in wetlands completely covered by macrophytes. The rotifer community distribution can be used to understand the trophic, current functional, and environmental status of wetlands. [ABSTRACT FROM AUTHOR]

• Fish genomes are under a strong influence of climate, habitat, and depth. • GS decreased with latitude, salinity, and depth, the GC contents increased. • Higher GC contents were found to be mostly associated with species occupying physiologically challenging or stressful environmental niches. • Opposing trends in GS and GC to be the hallmark of environmental adaptation in fishes. Environmental interactions and the effects of such interactions on the evolution of genome attributes is an intriguing area of ongoing research. Several earlier studies have delved into how the genome size (GS) and the guanine-cytosine content (GC) of genomes are shaped by species' ecology while largely disregarding other genome attributes, such as number of chromosomes (CR), number of genes (GE), and protein count (PC) from such comparisons. The present study was designed at understanding the influence of ecology––climate, habitat, and depth––on genome attributes by using the most current data on 579 whole fish genomes available at NCBI. Given the diverse and intricate roles of GS and GC in species adaptations to temperature, salinity, and hydrostatic pressure, the focus was on finding if and how the genomes responded to these stressors and if any common patterns existed in the genome-level responses. Our analyses exhibited some significant and intriguing trends for fishes as a whole while indicating strong effects of ecology on GS, GC, CR, and PC. Also, some very unique trends were observed on regressing GS and GC values across temperature, salinity, and depth clines. Accordingly, a very strong decline in the GS and a concomitant increase in GC were observed in species through the tropics/sub tropics to the temperate/poles, from freshwater to the marine habitats, and from the pelagic to bathydemersal depths. Observed patterns strongly support the notion that smaller GS and larger GC are associated with species inhabiting more stable environments and vice versa. The results also signify the effect of these patterns on protein flexibility and its role in tolerating stressful conditions. Observed patterns are discussed in the light of latitudinal biodiversity gradient, habitat complexity, and energy and metabolic expenditure hypothesis. [ABSTRACT FROM AUTHOR]

[Display omitted] • Phylogenomic analyses of UCEs reveal that Neaviperla is an invalid genus. • Jump dispersal has influenced the geographic distributions of Suwallia species. • Several Suwallia species appear to exhibit cryptic genetic diversity. • This is first ever reconstructed molecular phylogeny for Suwallia. • Museum specimens are useful for targeted sequencing techniques. Evolutionary biologists have long sought to disentangle phylogenetic relationships among taxa spanning the tree of life, an increasingly important task as anthropogenic influences accelerate population declines and species extinctions, particularly in insects. Phylogenetic analyses are commonly used to identify unique evolutionary lineages, to clarify taxonomic designations of the focal taxa, and to inform conservation decisions. Advances in DNA sequencing techniques have increasingly facilitated the ability of researchers to apply genomic methods to phylogenetic analyses, even for non-model organisms. Stoneflies are non-model insects that are important bioindicators of the quality of freshwater habitats and landscape disturbance as they spend the immature stages of their life cycles in fresh water, and the adult stages in terrestrial environments. Phylogenetic relationships within the stonefly genus Suwallia (Insecta: Plecoptera: Chloroperlidae) are poorly understood, and have never been assessed using molecular data. We used DNA sequence data from genome-wide ultraconserved element loci to generate the first molecular phylogeny for the group and assess its monophyly. We found that Palearctic and Nearctic Suwallia do not form reciprocally monophyletic clades, and that a biogeographic history including dispersal, vicariance, and founder event speciation via jump dispersal best explains the geographic distribution of this group. Our results also strongly suggest that Neaviperla forcipata (Neave, 1929) is nested within Suwallia , and the concept of the genus Suwallia should be revised to include it. Thus, we formally propose a new taxonomic combination wherein Neaviperla forcipata (Neave, 1929) is reclassified as Suwallia forcipata (Neave, 1929). Moreover, some Suwallia species (e.g., S. amoenacolens , S. kerzhneri , S. marginata, S. pallidula, and S. starki) exhibit pronounced cryptic diversity that is worthy of further investigation. These findings provide a first glimpse into the evolutionary history of Suwallia , improve our understanding of stonefly diversity in the tribe Suwallini, and highlight areas where additional research is needed. [ABSTRACT FROM AUTHOR]

The diversity, distribution, and checklist of diaptomid copepods from various freshwater ecosystems throughout Thailand are presented, based on data from our biodiversity projects during 1993–2019 and literature reviews. Thailand has one of the most diversified diaptomid fauna in the world, with 42 species identified from 2150 localities (4962 samples). Mongolodiaptomus has the highest species richness with ten species, followed by Tropodiaptomus with seven species. Among these, eight taxa (Arctodiaptomus sp., Mongolodiaptomus pectinidactylus, Neodiaptomus meggitti, Tropodiaptomus hebereri, T. lanaonus, T. oryzanus, T. ruttneri, and Paradiaptomus greeni) are new to the fauna of Thailand. The rare P. greeni, which predominantly occurs in Africa, is also a new record for Southeast Asia. The most frequently encountered species were Mongolodiaptomus botulifer, Phyllodiaptomus praedictus, M. calcarus, M. dumonti, M. malaindosinensis, Vietodiaptomus blachei, Phyllodiaptomus christineae, Eodiaptomus sanoamuangae, Neodiaptomus yangtsekiangensis, E. draconisignivomi, T. vicinus, and Heliodiaptomus elegans. Twelve species appear to be endemic to Thailand, and eight species occur only in the countries belonging to the lower Mekong River Basin (Thailand, Cambodia, Laos, and Vietnam). The uniqueness of the Thai diaptomids is a high degree of co-occurrence of four to seven species in the same localities. Comments on the taxonomic status of the species recorded are provided. In addition, the taxonomic validity of Mongolodiaptomus malaindosinensis is discussed. [ABSTRACT FROM AUTHOR]