Familial hematuria

Hematuria is a common presenting complaint in pediatric nephrology clinics and often has a familial basis. This teaching article provides an overview of causes, diagnosis, and management of the major forms of familial hematuria, Alport syndrome, and thin basement membrane nephropathy

Fish and mussels: importance of fish for freshwater mussel conservation

Co-extinctions are increasingly recognized as one of the major processes leading to the global biodiversity crisis, but there is still limited scientific evidence on the magnitude of potential impacts and causal mechanisms responsible for the decline of affiliate (dependent) species. Freshwater mussels (Bivalvia, Unionida), one of the most threatened faunal groups on Earth, need to pass through a parasitic larval (glochidia) phase using fishes as hosts to complete their life cycle. Here, we provide a synthesis of published evidence on the fish–mussel relationship to explore possible patterns in co-extinction risk and discuss the main threats affecting this interaction. We retrieved 205 publications until December 2015, most of which were performed in North America, completed under laboratory conditions and were aimed at characterizing the life cycle and/or determining the suitable fish hosts for freshwater mussels. Mussel species were reported to infest between one and 53 fish species, with some fish families (e.g., Cyprinidae and Percidae) being used more often as hosts than others. No relationship was found between the breadth of host use and the extinction risk of freshwater mussels. Very few studies focused on threats affecting the fish–mussel relationship, a knowledge gap that may impair the application of future conservation measures. Here, we identify a variety of threats that may negatively affect fish species, document and discuss the concomitant impacts on freshwater mussels, and suggest directions for future studies.The Portuguese Foundation for Science and Technology—FCT through POPH/FSE funds supported VM, MI and MLL under grants (SFRH/BD/108298/2015), (SFRH/BPD/90088/2012), (SFRH/BD/115728/2016), respectively. KD acknowledges the support from the Czech Science Foundation (13-05872S). RS acknowledges the support of the strategic programme UID/BIA/04050/2013 (POCI-01-0145- FEDER-007569) funded by national funds through the FCT I.P. and by the ERDF through the COMPETE2020-Programa Operacional Competitividade e Internacionalização (POCI). This study was conducted as part of the project FRESHCO: Multiple implications of invasive species on Freshwater Mussel co-extinction processes, supported by FCT (contract: PTDC/AGRFOR/1627/2014)

The hierarchical effects of anthropogenic impacts and natural filters on the distribution of freshwater mussels in the Hawkesbury-Nepean River, NSW, Australia

In comparison with North America, there is a poor level of taxonomic diversity in the Australian freshwater mussel fauna. Seventeen endemic hyriid species have been recorded in this country, while over 30 species have been recorded from one reach of a US river. While there have been no extinctions recorded among Australian mussel species, there are several species under threat, and mussel populations in many river systems are in serious decline. One of these catchments, the Hawkesbury-Nepean River, is considered to be among the most highly impacted of the eastern coastal rivers. Mussel populations in this river are believed to have declined in density and distribution, but to date this observation has been based on anecdotal, rather than scientific, evidence. This study aims to address the dearth of knowledge regarding population ecology for hyriid species by compiling a detailed assessment of mussel species, densities and sizes for a series of 100 sites throughout the greater Hawkesbury-Nepean River. Mussel populations were sampled concurrently with a range of physical habitat variables to identify natural and anthropogenic factors that may be important for defining the observed mussel assemblage structure. The results from these assessments were used to develop a hierarchical model that ranked the relative importance of these physical habitat variables in determining mussel distribution. An initial survey of sites in the Nepean River indicated that a high level of riparian disturbance was strongly related with decreased mussel density, and often with the apparent absence of mussels from many sites. Distribution of species and density of mussel assemblages were strongly associated with geomorphic reach type, so that different reaches supported different suites of mussel species. Presence of mussels was strongly associated with annual maximum dissolved oxygen, minimum total nitrogen, and minimum conductivity. Each species was associated with different annual patterns of water quality. Velesunio ambiguus were most frequently associated with maximum dissolved oxygen, and minimum conductivity and total phosphorus. In contrast, Hyridella depressa were not linked with dissolved oxygen patterns, but were negatively affected by turbidity and total phosphorus. Hyridella australis were associated with annual maximum dissolved oxygen, and not apparently affected by other aspects of water quality. Densities of mussels were compared with single samples for water quality at a second set of sites. Data from this study suggested that at higher densities, mussel populations impacted water quality, rather than water quality impacting mussel populations. The results indicated that at higher densities, mussels were able to favourably impact on water quality, reducing levels of phosphorus in the water column. Both small and large impoundments were seen to influence the composition of mussel assemblages. The presence of a large impoundment, mid catchment, was strongly associated with the absence of mussels upstream, and the presence of lower density populations. For small impoundments, weir height and geomorphic reach type were linked with differences in species distribution and densities. Velesunio ambiguus were present in greater densities in pools above weirs, while H. depressa and H. australis were present in higher numbers below weirs. Differences in distribution were also observed among different size classes of mussels. Small mussels were virtually absent above the large impoundment. Below the large impoundment, they were mostly found below small weirs located in less impacted sandstone gorge reaches. Within reaches, mussel distribution was most frequently related with coarse sand and the presence of a roughness element characteristic for the geomorphic reach type. Small mussels were associated with boulder stabilised habitats, and medium mussels with cobble based habitats. Large mussels were rarely associated with any type of roughness element. While each species showed some microhabitat preference, this was generally associated with the geomorphic reach type, rather than a particular aspect of substrate conditions. Within a hierarchy, catchment scale variables, including position in relation to a major impoundment, tended to dominate the delineation of mussel presence. Some aspects of water quality were associated with mussel density at a reach scale. The level of riparian disturbance, a reach scale factor, was strongly associated with mussel density. In general, factors associated with larger scales for the river were more influential in determining mussel presence and mussel density. However, the exact nature of these factors varied among species. When compared with northern hemisphere mussel fauna, Australian hyriid species were affected by a similar range of impacting factors. While the distribution of mussel species throughout the catchment was originally defined by natural filters, much of their present distribution patterns can be directly linked with anthropogenic changes within this highly impacted river system. Many of these anthropogenic impacts operate at catchment and reach scales, with the result that suitable habitats may not be colonised in some reaches of the river

Hotspots of biodiversity or homogeneous landscapes? : farm dams as biodiversity reserves in Australia

In many countries the ubiquitous farm dam or pond is an integral component of agricultural landscapes. In Australia there are in excess of half a million farm ponds, used largely for irrigation or for watering stock. In contrast to Europe, these wetlands are being decommissioned in response to the introduction of government policy that regulates water usage from these dams. They are also being in-filled with expanding urbanisation without consideration of their benefits as reservoirs of biodiversity. We compared the diversity of macroinvertebrates in farm dams with nearby stream habitats on a cool temperate tableland in central New South Wales. There was greater diversity in-stream than in the dams; however, dam sites showed a larger mean diversity and total diversity per site than instream. Species recorded in-stream were more frequently represented by single individuals while species were recorded more consistently in dams. We also observed that macroinvertebrate assemblages were more similar to those in the same dam in different seasons than to adjacent dams in the same season. Some species recorded had not previously been recorded from farm dams. In contrast to the general consensus that Australian farm dams are homogeneous environments with a range of common widespread species, we showed that they provide a variety of sustainable reservoirs of biodiversity within the landscape. They also have the potential to provide ‘stepping stones’ between undisturbed and modified habitats, in part countering the fragmentation that occurs as a result of agricultural practices

The Impact of Small and Large Impoundments on Freshwater Mussel Distribution in the Hawkesbury-Nepean River, Southeastern Australia

The influence of weirs on the distribution of freshwater mussels was investigated in the Hawkesbury-Nepean River, Australia. Distribution of species and densities of size classes were strongly correlated with catchment level factors (e.g. location around a major impoundment, stream order). At catchment scale, weir height, presence of a fish barrier, fish ladder type and position above or below small weirs did not influence the presence/absence of mussel populations. Lower mussel densities in the upper catchment may therefore reflect inhibition of host fish migration. Where present, weir height and geomorphic reach type were linked to differences in densities among species. Geomorphic reach-based differences were reflected by the Hyridella species, but not Velesunio ambiguus. When population structure was described by size class distribution, there were significant differences between densities of small and medium mussels from weirs above, compared to weirs below, a major impoundment, but not for large mussels. Upstream populations may therefore be functionally extinct. Distribution of mussel size classes differed among geomorphic reach types with highest densities for each class found in the least human-impacted reaches. Small mussels were almost invariably found below the major impoundment, most frequently below weirs. Distribution patterns were inconsistent across species, suggesting habitat preference. V. ambiguus and Hyridella australis were most abundant in shale reaches, where assemblages were influenced by fish ladder type. Hyridella depressa and H. australis dominated in sandstone gorges and straights with assemblage density related to weir height. In upper catchment sandstone reaches, mussel assemblages comprising predominantly V. ambiguus were influenced by fish ladder type and weir height. While multiple factors defined localized distribution, large impoundments were linked with reduced population densities. The probable mechanism is the restriction of host fish movement and resulting lack of recruitment. In the Hawkesbury-Nepean River, smaller weirs also seriously impacted recruitment

An exploration of the relationships between macroinvertebrate community composition and physical and chemical habitat characteristics in farm dams

Recently, Australian interest in farm dams has focused on rates of harvest of surface waters (runoff), and the impact this has on nearby natural systems. Little research has been directed towards the role of these artificial water bodies in sustaining biological reserves within the wider ecosystem. Macroinvertebrate communities in three farm dams in the Central Tablelands of New South Wales were surveyed, and water quality variables were correlated with species richness and abundance. Community responses to habitat factors including sediment depth, stock use, vegetation and debris were also examined. Communities were described at several taxonomic levels in addition to allocation to trophic groups and primary functional feeding groups. Species richness and abundance of communities were found to vary between dams and between habitat types within dams. The extent of these differences was decreased when communities were described by either trophic status or functional feeding mechanisms. Habitats were influenced by water quality and by physical features of the habitat, with the two factors interacting to define equilibrium conditions. Localised conditions resulted in different macroinvertebrate communities. Physicochemical parameters that correlated most closely with communities included light penetration, chlorophyll-a and conductivity. Habitat factors that were most frequently linked with communities were sediment depth and canopy cover, with localised disturbances related to stock use affecting feeding groups rather than specific taxa. One of the major problems associated with increasing modification of landscapes by agriculture or urbanisation is the fragmentation of undisturbed habitats. Creation of joint aquatic and woodland habitats enhances biodiversity corridors. The recognition of the potential for farm dams as reservoirs of biodiversity and development of management practices that optimise this neglected biodiversity reserve may have much wider benefits biologically, aesthetically and productively

Is the decline of freshwater mussel populations in a regulated coastal river in south-eastern Australia linked with human modification of habitat?

1. The Hawkesbury-Nepean River provides potable water for 5 million people living in the Sydney basin, and water for agricultural and horticultural production that meets most of Sydney's daily needs for fresh food. Anecdotal evidence indicated that numbers of freshwater mussels have seriously declined in much of the river over recent decades. 2. A field survey revealed the presence of populations of three species of mussels, Hyridella depressa, Hyridella australis and Velesunio ambiguus in the river. Higher density mussel populations were most common in catchment areas with little human modification to the channel bed or adjacent vegetation communities. 3. Levels of disturbance of riparian vegetation and, to a lesser degree, land use, were identified as being strongly associated with the absence of mussels from some reaches. 4. Catchment geomorphology was also shown to be relevant to the abundance, population structure and suite of mussel species present in different geomorphic reaches of the river. Absence of mussels was noted from areas where they had been recorded in previous studies. These results demonstrate that mussel species are under threat in the catchment. 5. As filter feeders with the ability to remove excess nutrients and bioaccumulate toxic substances, freshwater mussels play an important role in natural remediation processes in freshwater systems. 6. The decline in mussel populations in the Hawkesbury-Nepean River highlights concerns for the overall health of the river system, and supports the need to identify the subsidiary impacts of physical habitat modification in developing both riverine and riparian management strategies

Temporal variations in water quality of farm dams : impacts of land use and water sources

Three farm dams near Raglan, New South Wales (Australia), were compared to investigate diurnal and seasonal patterns in water quality over a period of 1 year. The source of water in one dam was predominantly influenced by groundwater, another showed links with both groundwater and agricultural runoff, and the third collected runoff from urban and agricultural lands with no apparent groundwater input. Patterns in chemical profiles were compared to identify level of similarity in macro-trends of water quality. Within dams, micro-trends were contrasted with known chemical relationships in dam waters to explore links between land use and water quality. The three dams were shown to have quite distinct patterns of water chemistry. Within dams, trends were strongly linked with the differing water sources, evidenced by chemical patterns that matched those expected from the different dominant ion transfer pathways associated with surface water and groundwater flow processes. Phosphates were primarily linked with groundwater fluctuations, nitrogen as ammonium ions with urban runoff, and nitrates with storm events resulting in runoff from pastures. We conclude that, for farm dams, the combination of land use and preferential flow paths gives a more complete description of water quality impacts than land use alone

The role of geomorphology in substratum patch selection by freshwater mussels in the Hawkesbury-Nepean River (New South Wales) Australia

1. Microhabitat preferences of freshwater mussels and associated substrate characteristics were investigated across a range of geomorphic reaches in the Hawkesbury-Nepean River, Australia. 2. The structure of substratum patches available was strongly influenced by geomorphic reach type. In each reach type, mussel distribution was most frequently correlated with coarse sand and a roughness element characteristic for that reach. Roughness elements such as boulders and cobbles create a flow refuge and were linked with mussel size. 3. Small mussels tended to be associated with boulder-stabilized habitats and medium sized mussels with cobble habitats. Large mussels rarely co-occurred with any particular roughness element. Individual species were strongly linked to geomorphic reach type. This association may be due to species' differences in ability to colonize available microhabitat types. 4. The highly tolerant Velesunio ambiguus dominated shale reaches, characterized by fine sediments and human impacts. In contrast, Hyridella depressa dominated in gorges, utilizing small flow refuges among boulders, while H. australis were present in low densities across a range of substrate conditions. 5. The persistence of multispecies assemblages in mussel beds throughout the Hawkesbury-Nepean River implies similar niche utilization among species. Partitioning of habitats across species on the basis of size suggests some degree of habitat selection, or differential survival. At the local scale, microhabitat characteristics influenced the size distribution and densities of mussel assemblages. Continuing declines in mussel densities are likely to result from ongoing channel modification and increased siltation resulting from changes to riparian vegetation