A counterfactual approach to measure the impact of wet grassland conservation on U.K. breeding bird populations

Wet grassland populations of wading birds in the United Kingdom have declined severely since 1990. To help mitigate these declines, the Royal Society for the Protection of Birds has restored and managed lowland wet grassland nature reserves to benefit these and other species. However, the impact of these reserves on bird population trends has not been evaluated experimentally due to a lack of control populations. We compared population trends from 1994 to 2018 among 5 bird species of conservation concern that breed on these nature reserves with counterfactual trends created from matched breeding bird survey observations. We compared reserve trends with 3 different counterfactuals based on different scenarios of how reserve populations could have developed in the absence of conservation. Effects of conservation interventions were positive for all 4 targeted wading bird species: Lapwing (Vanellus vanellus), Redshank (Tringa totanus), Curlew (Numenius arquata), and Snipe (Gallinago gallinago). There was no positive effect of conservation interventions on reserves for the passerine, Yellow Wagtail (Motacilla flava). Our approach using monitoring data to produce valid counterfactual controls is a broadly applicable method allowing large-scale evaluation of conservation impact.     

Evidence of nitrification and denitrification in high and low microbial abundance sponges

Aerobic and anaerobic microbial key processes were quantified and compared to microbial numbers and morphological structure in Mediterranean sponges. Direct counts on histological sections stained with DAPI showed that sponges with high microbial abundances (HMA sponges) have a denser morphological structure with a reduced aquiferous system compared to low microbial abundance (LMA) sponges. In Dysidea avara, the LMA sponge, rates of nitrification and denitrification were higher than in the HMA sponge Chondrosia reniformis, while anaerobic ammonium oxidation and sulfate reduction were below detection in both species. This study shows that LMA sponges may host physiologically similar microbes with comparable or even higher metabolic rates than HMA sponges, and that anaerobic processes such as denitrification can be found both in HMA and LMA sponges. A higher concentration of microorganisms in the mesohyl of HMA compared to LMA sponges may indicate a stronger retention of and, hence, a possible benefit from associated microbes.     

A herbivore specific grazing capacity model accounting for spatio-temporal environmental variation: A tool for a more sustainable nature conservation and rangeland management

Grazing with livestock is a common feature of nature and rangeland management. Although both aim at different, seemingly opposing goals, i.e. maintenance of biodiversity values versus maximization of animal production, they nonetheless have a common interest in maintaining the rangeland or natural environment in a state that ensures either the first or the second goal. In order to accomplish an effective and efficient grazing management, in terms of grazer density, grazer composition, grazing seasonality, and to prevent under- and overgrazing, a grazing capacity model (GCM) was developed, that should be applicable in both rangeland and nature conservation management conditions and that takes spatio-temporal environmental variation into account. This spatio-temporally dynamic model considers crucial variables at both the terrain and the grazer level, such as (seasonally) fluctuating forage yield, forage quality, plant palatability, accessibility of the area, soil erosion vulnerability, animal nutritive requirements, animal behaviour and general habitat condition. It predicts the optimal grazer species and density, taking into account the seasonal variation in animal needs and fluctuating terrain characteristics. A sensitivity analysis was conducted to define each parameter's relative impact on the final outcome of the model.We present the GCM outline and illustrate the functionality of this model for Shetland ponies and Highland cattle, grazing in a temperate coastal dune environment. According to the model, seasonal fluctuations in optimal grazer densities occur: the area can support higher densities in summer and autumn than it can during winter and spring. With the current density of grazing animals and the choice for year-round grazing at non-fluctuating animal densities, the model consequently predicts overgrazing in winter and undergrazing in summer and autumn. Both undergrazing and overgrazing scenarios might lead to non-sustainable situations in the future.     

Dams and Flows: Immersing in Western Meaning Systems in Search of Ecocultural Reflexivity

In this unprecedented era of anthropogenic ecological destruction, this study illustrates inadequacies in conceptual language available in Western settings to think deeply and holistically about “nature.” At the same time, the study illustrates transformative potential of moments of ecocultural reflexivity. Using free write methodology, we examine ways participants in the United States, New Zealand, and Australia articulate what they mean when they say “nature.” We interpret participant streams of consciousness as representative of a wider Western river-way, a channel of dominant, multiple, and contradictory meanings in continuous movement. We identify conceptual obstructions that provide glimpses into ways Western ecological relations are bounded and dammed by binary, fragmented, and unconsidered meanings. Yet reflexivity in the face of such obstructions, and in potent ecocultural side streams of childhood remembering and ecocentric cosmology, provides some participants a lucid flow of regenerative narratives at a time such shared stories are urgently needed.     

The influence on the radioxenon background during the temporary suspension of operations of three major medical isotope production facilities in the Northern Hemisphere and during the start-up of another facility in the Southern Hemisphere

Medical isotope production facilities (MIPF) have recently been identified to emit the major part of the environmental radioxenon measured at many globally distributed monitoring sites deployed to strengthen the radionuclide component of the Comprehensive Nuclear-Test-Ban Treaty (CTBT) verification regime. Efforts to raise a global radioxenon emission inventory revealed that the yearly global total emission from MIPF’s is around 15 times higher than the total radioxenon emission from nuclear power plants (NPP's).Given that situation, from mid 2008 until early 2009 two out of the ordinary hemisphere-specific events occured:1) In the Northern hemisphere, a joint temporary suspension of operations of the three largest MIPF's made it possible to quantify the effects of the emissions related to NPP’s. The average activity concentrations of ¹³³Xe measured at a monitoring station close to Freiburg, Germany, went down significantly from 4.5 ± 0.5 mBq/m³ to 1.1 ± 0.1 mBq/m³ and in Stockholm, Sweden, from 2.0 ± 0.4 mBq/m³ to 1.05 ± 0.15 mBq/m³.2) In the Southern hemisphere the only radioxenon-emitting MIPF in Australia started up test production in late November 2008. During eight test runs, up to 6.2 ± 0.2 mBq/m³ of ¹³³Xe was measured at the station in Melbourne, 700 km south-west from the facility, where no radioxenon had been observed before, originating from the isotopic production process.This paper clearly confirms the hypothesis that medical isotope production facility are at present the major emitters of radioxenon to the atmosphere. Suspension of operations of these facilities indicates the scale of their normal contribution to the European radioxenon background, which decreased two to four fold. This also gives a unique opportunity to detect and investigate the influence of other local and long distance sources on the radioxenon background. Finally the opposing effect was studied: the contribution of the start-up of a renewed radiopharmaceutical facility to the build up of a radioxenon background across Australia and the Southern hemisphere.     

Evaluation of radioxenon releases in Australia using atmospheric dispersion modelling tools

The origin of a series of atmospheric radioxenon events detected at the Comprehensive Test Ban Treaty Organisation (CTBTO) International Monitoring System site in Melbourne, Australia, between November 2008 and February 2009 was investigated. Backward tracking analyses indicated that the events were consistent with releases associated with hot commission testing of the Australian Nuclear Science Technology Organisation (ANSTO) radiopharmaceutical production facility in Sydney, Australia. Forward dispersion analyses were used to estimate release magnitudes and transport times. The estimated ¹³³Xe release magnitude of the largest event (between 0.2 and 34 TBq over a 2 d window), was in close agreement with the stack emission releases estimated by the facility for this time period (between 0.5 and 2 TBq). Modelling of irradiation conditions and theoretical radioxenon emission rates were undertaken and provided further evidence that the Melbourne detections originated from this radiopharmaceutical production facility. These findings do not have public health implications. This is the first comprehensive study of atmospheric radioxenon measurements and releases in Australia.     

Facing Hazardous Matter in Atmospheric Particles with NanoSIMS (2 pp)

Background, Aim and Scope Current scientific studies and evaluations clearly show that an increase of urban dust loads, alone or combined with other pollutants und certain meteorological conditions lead to different significant health effects. Premature death, increased hospital admissions and increased respiratory symptoms and diseases as well as decreased lung function can be observed in combination with high pollutant levels. Sensitive groups like elderly people or children and persons with cardiopulmonary diseases such as asthma are more strongly affected. Because of the direct contact between fine particles and lung tissue more information concerning the surface structure (mapping of toxic elements) is required. Materials and Methods: The NanoSims50 ion microprobe images the element composition at the surface of sub-micrometer air dust particles and documents hot spots of toxic elements as a possible threat for human health. Results: The atmospheric fine dust consists of a complex mixture of organic and inorganic compounds. Heavy metals are fixed on airborn particles in the form of hot spots in a nanometer scale. From a sanitary point of view, the hot spots consisting of toxic elements are particularly relevant as they react directly with the lung tissues. Discussion: To what extent particles can penetrate the various areas of the lungs and be deposited there depends on the one hand on their physical characteristics and on the other on breathing patterns and the anatomy of the lung, which is subject to change as the result of growth, ageing or illness. Once inhaled, some particles can reach the pulmonary alveoli and thus directly expose the lung tissues to toxic elements. Conclusions: Especially the mapping of toxic arsenic or heavy metals like copper on the dust particles shows local hot spots of pollution in the dimension of only 50 nanometers. Recommendations and Perspectives: Imaging of elements in atmospheric particles with NanoSIMS will help to identify the material sources.     

Effects of sediment quality on macroinvertebrates in the Sunraysia region of the Murray-Darling Rivers, Australia

A field-based microcosm approach was tested to identify deterioration of sediment quality in waterways using freshwater macroinvertebrates. The method can potentially identify the nature of contaminants based on species-specific responses. Sediments were collected from the Murray and Darling Rivers and irrigation drains within the Sunraysia region of south-eastern Australia and compared to non-polluted reference sediment. Clean sediments were also spiked with fertiliser to test whether nutrients affected the aquatic fauna. Seven of the eight sediments from the Sunraysia region had a negative impact on the macroinvertebrates, in particular sediment from the Darling River, which supported an impoverished fauna. Three species of chironomid showed varied responses to sediment quality and, although it was hypothesised that nutrients may have impacted on the macroinvertebrate fauna, the results suggest that other pollutants are also involved. The field-based microcosm method proved effective for determining the impact of sediment quality on indigenous macroinvertebrates.