Continental impacts of water development on waterbirds, contrasting two Australian river basins: Global implications for sustainable water use

Loss of terrestrial biodiversity in Australia: Magnitude, causation, and response

Australia's biota is species rich, with high rates of endemism. This natural legacy has rapidly diminished since European colonization. The impacts of invasive species, habitat loss, altered fire regimes, and changed water flows are now compounded by climate change, particularly through extreme drought, heat, wildfire, and flooding. Extinction rates, already far exceeding the global average for mammals, are predicted to escalate across all taxa, and ecosystems are collapsing. These losses are symptomatic of shortcomings in resourcing, law, policy, and management. Informed by examples of advances in conservation practice from invasive species control, Indigenous land management, and citizen science, we describe interventions needed to enhance future resilience. Many characteristics of Australian biodiversity loss are globally relevant, with recovery requiring society to reframe its relationship with the environment.

Resilience to hydrological droughts in the northern Murray-Darling Basin, Australia

We respond to the problem of declining streamflows in the northern Murray–Darling Basin, Australia, a region that suffers from hydrological droughts and a drying trend. We partitioned the effect of meteorological trends from anthropogenic drivers on annual streamflow, quantified the effect of annual streamflow decline on waterbird abundance, estimated the effects of streamflow change on a measure of ecosystem resilience, and calculated the net benefits of in-stream water reallocation. The anthropogenic drivers of hydrological droughts were assessed by comparing the Lower Darling (hereafter the Barka) River, which has large recorded water extractions, with the adjacent Paroo River, which has very little recorded water extractions. Findings include: (1) only about one-third of the recent reduced streamflow of the Barka River is due to a meteorological drying trend; (2) statistically significant declines in waterbird species richness and abundance have occurred on both rivers between 1983–2000 and 2001–2020; (3) declines in waterbird abundance have been much larger along the Barka River than the Paroo River; and (4) ecosystem resilience, as measured by waterbird abundance, wasgreater on the Paroo River. Our four-step framework is applicable in any catchment with adequate time-series data and supports adaptive responses to hydrological droughts.

This article is part of the Royal Society Science+ meeting issue ‘Drought risk in the Anthropocene’.

Protected areas have a mixed impact on waterbirds, but management helps

International policy is focused on increasing the proportion of the Earth's surface that is protected for nature^1,2. Although studies show that protected areas prevent habitat loss^3-6, there is a lack of evidence for their effect on species' populations: existing studies are at local scale or use simple designs that lack appropriate controls^7-13. Here we explore how 1,506 protected areas have affected the trajectories of 27,055 waterbird populations across the globe using a robust before-after control-intervention study design, which compares protected and unprotected populations in the years before and after protection. We show that the simpler study designs typically used to assess protected area effectiveness (before-after or control-intervention) incorrectly estimate effects for 37-50% of populations-for instance misclassifying positively impacted populations as negatively impacted, and vice versa. Using our robust study design, we find that protected areas have a mixed impact on waterbirds, with a strong signal that areas managed for waterbirds or their habitat are more likely to benefit populations, and a weak signal that larger areas are more beneficial than smaller ones. Calls to conserve 30% of the Earth's surface by 2030 are gathering pace¹⁴, but we show that protection alone does not guarantee good biodiversity outcomes. As countries gather to agree the new Global Biodiversity Framework, targets must focus on creating and supporting well-managed protected and conserved areas that measurably benefit populations.

More Than Just a Trend: Integrating Population Viability Models to Improve Conservation Management of Colonial Waterbirds

Waterbird populations in eastern Australia have been declining over the past 35 years primarily due to water resource development and resultant changes to natural river flows and flooding. To mitigate these impacts there is an increased allocation of water for the environment, including waterbird populations. We used population viability models to identify the frequency of breeding events required to reverse the trend and achieve long-term species' management objectives. We found that the population size of straw-necked ibis was primarily dictated by the frequency of large breeding events and to a lesser extent by adult annual survival and the frequency of small breeding events. We identified combinations of small and large breeding events over the next 10 years required for increased population growth. We also assessed the likelihood of current water management policies increasing populations and thereby reversing the decline in eastern Australia's waterbird populations.

Seasonal dynamics of waterbirds from a relict wetland in the central Monte Desert, Argentina

Wetlands currently have high rates of degradation, with more than 70% lost globally. In the central Monte Desert, Argentina, they are a scarce and limited resource for the biodiversity which depends on them. Waterbirds have been used as biological indicators of wetlands because they respond to fluctuations in food resources and to environmental changes in the short term. Here we analyse the seasonal variations in the structure of the waterbird assemblage from a relict wetland in this region. We carried out censuses of waterbirds in a 6-year period (between 2009 and 2019) during the southern summer and winter. We recorded 1875 individuals of 33 species of waterbirds during the summer and 677 individuals of 29 species during the winter. The grouping patterns of the waterbird assemblages differed between seasons (R = 0.35; p < 0.01). Taxonomic diversity profiles showed greater diversity for all indexes (qD) during the summer. The guild of invertivorous and omnivorous waders had a greater abundance of individuals during the summer (p < 0.05) and, together with the surface-feeding herbivores, contributed to the 87% of the dissimilarity of the assemblages between seasons. Phoenicopterus chilensis was the only species registered as threatened with national and international extinction. Relict wetlands, such as Laguna del Viborón, still have attributes of community diversity and represent the last refuges for waterbirds of the central Monte Desert. The information gathered in this study will contribute to the guidelines for integrated management plans and monitoring programmes for the conservation of the wetland and its biodiversity.

The influence of hydrological variables, climatic variables and food availability on Anatidae in interconnected river-lake systems, the middle and lower reaches of the Yangtze River floodplain

Hydrology-climate changes and food availability are expected to be the primary drivers that result in a loss of waterbirds diversity. Non-biological factors are vital to food availability in interconnected river-lake systems, so in addition to identifying the ecological response to drivers, it is also important to analyze and quantify relationships between drivers. In order to explore the impacts of these drivers on the wintering waterbirds, we selected Dongting Lake (DTL) as a study area, which is a typical interconnected river-lake system in the middle and lower reaches of the Yangtze River Floodplain. The Anatidae species, most of which are herbivorous, were chosen as the representative waterfowl. The Pearson correlation coefficient was applied to select variables related to the timing of water recession and food availability, which have significant influences on the Anatidae. Then, the structural equation model (SEM) was carried out to quantify the relationships among the food availability, hydrological variables, and climatic variables. The results showed that unseasonably early or late water recession had a negative impact on the diversity of the Anatidae, and in particular affected population dynamics of the Lesser White-fronted goose Anser erythropus. Significant changes in Anatidae populations in DTL occurred in response to maximum NDVI (r = 0.53, p<0.01) and the interval time of water recession (r = -0.43, p<0.1). Water level, flow, and interval time of water recession explained 71% of maximum NDVI in DTL. In addition, hydraulic interactions between the mainstream and each lake jointly affected the inundation pattern and the vegetation growth stage of the lake after the flood season, thus affecting foraging suitability. Our findings suggest that water compensation should be carried out within an appropriate range of hydraulic gradient to optimize the time of water recession and improve the suitability of the habitat effectively.

Scientists' warning to humanity on the freshwater biodiversity crisis

Freshwater ecosystems provide irreplaceable services for both nature and society. The quality and quantity of freshwater affect biogeochemical processes and ecological dynamics that determine biodiversity, ecosystem productivity, and human health and welfare at local, regional and global scales. Freshwater ecosystems and their associated riparian habitats are amongst the most biologically diverse on Earth, and have inestimable economic, health, cultural, scientific and educational values. Yet human impacts to lakes, rivers, streams, wetlands and groundwater are dramatically reducing biodiversity and robbing critical natural resources and services from current and future generations. Freshwater biodiversity is declining rapidly on every continent and in every major river basin on Earth, and this degradation is occurring more rapidly than in terrestrial ecosystems. Currently, about one third of all global freshwater discharges pass through human agricultural, industrial or urban infrastructure. About one fifth of the Earth's arable land is now already equipped for irrigation, including all the most productive lands, and this proportion is projected to surpass one third by midcentury to feed the rapidly expanding populations of humans and commensal species, especially poultry and ruminant livestock. Less than one fifth of the world's preindustrial freshwater wetlands remain, and this proportion is projected to decline to under one tenth by midcentury, with imminent threats from water transfer megaprojects in Brazil and India, and coastal wetland drainage megaprojects in China. The Living Planet Index for freshwater vertebrate populations has declined to just one third that of 1970, and is projected to sink below one fifth by midcentury. A linear model of global economic expansion yields the chilling prediction that human utilization of critical freshwater resources will approach one half of the Earth's total capacity by midcentury. Although the magnitude and growth of the human freshwater footprint are greater than is generally understood by policy makers, the news media, or the general public, slowing and reversing dramatic losses of freshwater species and ecosystems is still possible. We recommend a set of urgent policy actions that promote clean water, conserve watershed services, and restore freshwater ecosystems and their vital services. Effective management of freshwater resources and ecosystems must be ranked amongst humanity's highest priorities.

Aerial surveys of waterbirds in Australia

Tracking long-term environmental change is important, particularly for freshwater ecosystems, often with high rates of decline. Waterbirds are key indicators of freshwater ecosystem change, with groups reflecting food availability (e.g. piscivores and fish). We store waterbird (species abundance, numbers of nests and broods) and wetland area data from aerial surveys of waterbirds across Australia, mostly at the species’ level (∼100 species) from three aerial survey programs: Eastern Australian Waterbird Survey, National Survey and Murray-Darling Basin wetlands. Across eastern Australia, we survey up to 2,000 wetlands annually (October, since 1983), along 10 survey bands (30 km wide), east to west across about one third of Australia. In 2008, we surveyed 4,858 wetlands across Australia and each year (since 2010) we survey the major wetlands in the Murray-Darling Basin. These data inform regulation of hunting seasons in Victoria and South Australia, Game bird culling in NSW, State of the Environment Reporting, environmental assessments, river and wetland management, the status of individual species and identification of high conservation sites.

Measurement(s)	population • numbers of waterbird species • brood size • nest count
Technology Type(s)	visual observation method
Factor Type(s)	year • geographic location
Sample Characteristic - Organism	Aves
Sample Characteristic - Environment	wetland area
Sample Characteristic - Location	Australia

Machine-accessible metadata file describing the reported data: 10.6084/m9.figshare.12280112

Optimized health care for subjects with type 1 diabetes in a resource constraint society: A three-year follow-up study from Pakistan

BACKGROUND

Inadequate health infrastructure and poverty especially in rural areas are the main hindrance in the optimal management of subjects with type 1 diabetes (T1D) in Pakistan.

AIM

To observe effectiveness of diabetes care through development of model clinics for subjects with T1D in the province of Sindh Pakistan.

METHODS

A welfare project with name of “Insulin My Life”, was started in province of Sindh, Pakistan. This was collaborative work of Baqai Institute of Diabetology and Endocrinology, World Diabetes Foundation and Baqai Medical University between February 2010 to February 2013. Under this project thirty-four T1D clinics were established. Electronic database was designed for demographic, biochemical, anthropometric and medical examination. Monthly consultation was part of the standardized diabetes care. All the recruited subjects with T1D were provided free insulins and related materials.

RESULTS

Out of 1428 subjects, 795 (55.7%) were males and 633 (44.3%) were females. Subjects were categorized into ≤ 5 years of age 103 (7.2%), between 6-12 years 323 (22.6%), between 13–18 years 428 (29.7%) and ≥ 19 years of age 574 (40.2%) groups. Glycemic control as assessed by HbA1c was significantly improved (P < 0.0001) at three years follow up as compared to baseline in all age groups. Decreasing trends of mean self-monitoring blood glucose were observed at different meal timings in all age groups. No significant change was found in the frequency of neuropathy, nephropathy and retinopathy during the study period (P > 0.05).

CONCLUSION

This study gives us long-term longitudinal data of people with T1D in a resource constraint society. With provision of standardized and comprehensive care significant improvement in glycemic control without any change in the frequency of microvascular complications was observed over 3 years.

Evaluation of the ecological protective effect of the "large basin" comprehensive management system in the Tarim River basin, China

It is very important to construct a reasonable and efficient basin management system to meet the ecological water demand in arid areas with natural vegetation, and to maintain the integrity and stability of fragile ecosystems. However, how to assess the effect of basin management on ecological protection in arid areas as well as how to achieve the optimal control and efficient use of ecological water are major issues for many researchers and river basin managers. To address these two questions, we investigated the comprehensive management system for the Tarim River basin in China as a typical case study. The results showed that the natural vegetation coverage degree, the ecological water supply, temperature vegetation dryness index (TVDI), and the tree-ring chronology of Populus euphratica increased, whereas the disturbance of water resources by human activities decreased. Therefore, the effects of ecological protection were obvious after comprehensive "large basin" management. Based on an innovative application of tree-ring chronology to estimate the water leakage from the river, we determined the minimum runoff level (43.1 × 10⁸ m³) when the natural vegetation needs to overflow. To further improve the effect of comprehensive management, the optimal regulation mode (i.e. maintaining the groundwater depth at 2-6 m, and the frequency and duration of overflowing at 2-3 times per year for a duration of 15-20 days during July to September) for the ecological sluices was formulated from the perspective of the efficient utilization of ecological water. These results provide a scientific reference for constructing reasonable management systems for similar river basins in arid areas.

The Water Governance Reform Framework: Overview and Applications to Australia, Mexico, Tanzania, U.S.A and Vietnam

The world faces critical water risks in relation to water availability, yet water demand is increasing in most countries. To respond to these risks, some governments and water authorities are reforming their governance frameworks to achieve convergence between water supply and demand and ensure freshwater ecosystem services are sustained. To assist in this reform process, the Water Governance Reform Framework (WGRF) is proposed, which includes seven key strategic considerations: (1) well-defined and publicly available reform objectives; (2) transparency in decision-making and public access to available data; (3) water valuation of uses and non-uses to assess trade-offs and winners and losers; (4) compensation for the marginalized or mitigation for persons who are disadvantaged by reform; (5) reform oversight and “champions”; (6) capacity to deliver; and (7) resilient decision-making. Using these reform criteria, we assess current and possible water reforms in five countries: Murray–Darling Basin (Australia); Rufiji Basin (Tanzania); Colorado Basin (USA and Mexico); and Vietnam. We contend that the WGRF provides a valuable approach to both evaluate and to improve water governance reform and, if employed within a broader water policy cycle, will help deliver both improved water outcomes and more effective water reforms.

The threats to Australia’s imperilled species and implications for a national conservation response

Since European occupation of Australia, human activities have caused the dramatic decline and sometimes extinction of many of the continent’s unique species. Here we provide a comprehensive review of threats to species listed as threatened under Australia’s Environment Protection and Biodiversity Conservation Act 1999. Following accepted global categories of threat, we find that invasive species affect the largest number of listed species (1257 species, or 82% of all threatened species); ecosystem modifications (e.g. fire) (74% of listed species) and agricultural activity (57%) are also important. The ranking of threats was largely consistent across taxonomic groups and the degree of species’ endangerment. These results were significantly different (P&lt;0.01) from recent analyses of threats to threatened species globally, which highlighted overexploitation, agriculture and urban development as major causes of decline. Australia is distinct not only in the biodiversity it contains but also in the extent and mixture of processes that threaten the survival of these species. Notably, the IUCN threat classification scheme separates the numerous threats (e.g. urban development, agriculture, mining) that cause habitat loss, fragmentation and degradation, hence further research is required to quantify the net impact of these types of habitat change. We provide feasible suggestions for a more coordinated national approach to threatened species conservation, which could provide decision makers and managers at all levels with improved resources and information on threats and management. Adequate policy, legislative support and funding are critical for ensuring that on-ground management is successful in halting the decline of Australia’s threatened species.

Estimating kangaroo density by aerial survey: a comparison of thermal cameras with human observers

Abstract ContextAerial surveys provide valuable information about the population status and distribution of many native and pest vertebrate species. They are vital for evidence-based monitoring, budget planning and setting management targets. Despite aircraft running costs, they remain one of the most cost-effective ways to capture distribution and abundance data over a broad area. In Australia, annual surveys of large macropods are undertaken in several states to inform management, and in some jurisdictions, to help set commercial kangaroo harvest quotas. Improvements in the cost efficiencies of these surveys are continually sought. Aerial thermal imaging techniques are increasingly being tested for wildlife surveys, but to date no studies have directly compared population data derived from thermal imaging with data collected by human observers during the same flight. AimsDuring an aerial survey of western grey kangaroos (Macropus fuliginosus), eastern grey kangaroos (M. giganteus) and red kangaroos (Osphranter rufus) across the state of Victoria, Australia, the objective was to conduct a direct comparison of the effectiveness of thermal camera technology and human observers for estimating kangaroo populations from aerial surveys. MethodsA thermal camera was mounted alongside an aerial observer on one side of the aircraft for a total of 1360km of transect lines. All thermal footage was reviewed manually. Population density estimates and distance sampling models were compared with human observer counts. Key resultsOverall, the kangaroo density estimates obtained from the thermal camera data were around 30% higher than estimates derived from aerial observer counts. This difference was greater in wooded habitats. Conversely, human-derived counts were greater in open habitats, possibly due to interference from sunlight and flushing. It was not possible to distinguish between species of macropod in the thermal imagery. ConclusionsThermal survey techniques require refining, but the results of the present study suggest that with careful selection of time of day for surveys, more accurate population estimates may be possible than with conventional aerial surveys. ImplicationsConventional aerial surveys may be underestimating animal populations in some habitats. Further studies that directly compare the performance of aerial observers and thermal imaging are required across a range of species and habitats.

Simplified procedure for efficient and unbiased population size estimation

Population size estimation is relevant to social and ecological sciences. Exhaustive manual counting, the density method and automated computer vision are some of the estimation methods that are currently used. Some of these methods may work in concrete cases but they do not provide a fast, efficient and unbiased estimation in general. Recently, the CountEm method, based on systematic sampling with a grid of quadrats, was proposed. It offers an unbiased estimation that can be applied to any population. However, choosing suitable grid parameters is sometimes cumbersome. Here we define a more intuitive grid parametrization, using initial number of quadrats and sampling fraction. A crowd counting dataset with 51 images and their corresponding, manually annotated position point patterns, are used to analyze the variation of the coefficient of error with respect to different parameter choices. Our Monte Carlo resampling results show that the error depends on the sample size and the number of nonempty quadrats, but not on the size of the target population. A procedure to choose suitable parameter values is described, and the expected coefficients of error are given. Counting about 100 particles in 30 nonempty quadrats usually yields coefficients of error below 10%.

Water level affects availability of optimal feeding habitats for threatened migratory waterbirds

Extensive ephemeral wetlands at Poyang Lake, created by dramatic seasonal changes in water level, constitute the main wintering site for migratory Anatidae in China. Reductions in wetland area during the last 15 years have led to proposals to build a Poyang Dam to retain high winter water levels within the lake. Changing the natural hydrological system will affect waterbirds dependent on water level changes for food availability and accessibility. We tracked two goose species with different feeding behaviors (greater white‐fronted geese Anser albifrons [grazing species] and swan geese Anser cygnoides [tuber‐feeding species]) during two winters with contrasting water levels (continuous recession in 2015; sustained high water in 2016, similar to those predicted post‐Poyang Dam), investigating the effects of water level change on their habitat selection based on vegetation and elevation. In 2015, white‐fronted geese extensively exploited sequentially created mudflats, feeding on short nutritious graminoid swards, while swan geese excavated substrates along the water edge for tubers. This critical dynamic ecotone successively exposes subaquatic food and supports early‐stage graminoid growth during water level recession. During sustained high water levels in 2016, both species selected mudflats, but also to a greater degree of habitats with longer established seasonal graminoid swards because access to tubers and new graminoid growth was restricted under high‐water conditions. Longer established graminoid swards offer less energetically profitable forage for both species. Substantial reduction in suitable habitat and confinement to less profitable forage by higher water levels is likely to reduce the ability of geese to accumulate sufficient fat stores for migration, with potential carryover effects on subsequent survival and reproduction. Our results suggest that high water levels in Poyang Lake should be retained during summer, but permitted to gradually recede, exposing new areas throughout winter to provide access for waterbirds from all feeding guilds.