A split flow chamber with artificial sediment to examine the below-ground microenvironment of aquatic macrophytes

We present a new experimental set-up enabling fine-scale examination of how changing environmental conditions affect the below-ground biogeochemical microenvironment of aquatic macrophytes. By means of microsensor and planar optode technology, the influence of plant-mediated radial O₂ release on the below-ground chemical microenvironment of Zostera muelleri and Halophila ovalis was determined in high spatio-temporal resolution. The seagrass specimens were cultured in a new split flow chamber with artificial sediment made of a deoxygenated seawater–agar solution with added sulphide. Microelectrode measurements revealed radial O₂ release from the root–shoot junction of both Z. muelleri and H. ovalis during both light stimulation and darkness, resulting in a rapid decrease in H₂S concentration, and a significant drop in pH was observed within the plant-derived oxic microzone of Z. muelleri. No radial O₂ release was detectable from the below-ground tissue of Z. muelleri during conditions of combined water-column hypoxia and darkness, leaving the plants more susceptible to sulphide invasion. The spatial O₂ heterogeneity within the immediate rhizosphere of Z. muelleri was furthermore determined in two dimensions by means of planar optodes. O₂ images revealed a decrease in the spatial extent of the plant-derived oxic microzone surrounding the below-ground tissue during darkness, supporting the microelectrode measurements. This new experimental approach can be applied to all rooted aquatic plants, as it allows for direct visual assessment of the below-ground tissue surface during microprofiling, while enabling modification of the above-ground environmental conditions.     

Protected species use of a coastal marine migratory corridor connecting marine protected areas

The establishment of protected corridors linking the breeding and foraging grounds of many migratory species remains deficient, particularly in the world’s oceans. For example, Australia has recently established a network of Commonwealth Marine Reserves, supplementing existing State reserves, to protect a wide range of resident and migratory marine species; however, the routes used by mobile species to access these sites are often unknown. The flatback marine turtle (Natator depressus) is endemic to the continental shelf of Australia, yet information is not available about how this species uses the marine area. We used a geospatial approach to delineate a coastal corridor from 73 adult female flatback postnesting migratory tracks from four rookeries along the north-west coast of Australia. A core corridor of 1,150 km length and 30,800 km² area was defined, of which 52 % fell within 11 reserves, leaving 48 % (of equivalent size to several Commonwealth Reserves) of the corridor outside of the reserve network. Despite limited data being available for other marine wildlife in this region, humpback whale migratory tracks overlapped with 96 % of the core corridor, while the tracks of three other species overlapped by 5–10 % (blue whales, olive ridley turtles, whale sharks). The overlap in the distribution ranges of at least 20 other marine vertebrates (dugong, cetaceans, marine turtles, sea snakes, crocodiles, sharks) with the corridor also imply potential use. In conclusion, this study provides valuable information towards proposing new locations requiring protection, as well as identifying high-priority network linkages between existing marine protected areas.     

The effect of protected areas on forest disturbance in the Carpathian Mountains 1985–2010

Protected areas are a cornerstone for forest protection, but they are not always effective during times of socioeconomic and institutional crises. The Carpathian Mountains in Eastern Europe are an ecologically outstanding region, with widespread seminatural and old‐growth forest. Since 1990, Carpathian countries (Czech Republic, Hungary, Poland, Romania, Slovakia, and Ukraine) have experienced economic hardship and institutional changes, including the breakdown of socialism, European Union accession, and a rapid expansion of protected areas. The question is how protected‐area effectiveness has varied during these times across the Carpathians given these changes. We analyzed a satellite‐based data set of forest disturbance (i.e., forest loss due to harvesting or natural disturbances) from 1985 to 2010 and used matching statistics and a fixed‐effects estimator to quantify the effect of protection on forest disturbance. Protected areas in the Czech Republic, Slovakia, and the Ukraine had significantly less deforestation inside protected areas than outside in some periods; the likelihood of disturbance was reduced by 1–5%. The effectiveness of protection increased over time in these countries, whereas the opposite was true in Romania. Older protected areas were most effective in Romania and Hungary, but newer protected areas were more effective in Czech Republic, and Poland. Strict protection (International Union for Conservation of Nature [IUCN] protection category Ia‐II) was not more effective than landscape‐level protection (IUCN III‐VI). We suggest that the strength of institutions, the differences in forest privatization, forest management, prior distribution of protected areas, and when countries joined the European Union may provide explanations for the strikingly heterogeneous effectiveness patterns among countries. Our results highlight how different the effects of protected areas can be at broad scales, indicating that the effectiveness of protected areas is transitory over time and space and suggesting that generalizations about the effectiveness of protected areas can be misleading.     

Defending the scientific integrity of conservation‐policy processes

Government agencies faced with politically controversial decisions often discount or ignore scientific information, whether from agency staff or nongovernmental scientists. Recent developments in scientific integrity (the ability to perform, use, communicate, and publish science free from censorship or political interference) in Canada, Australia, and the United States demonstrate a similar trajectory. A perceived increase in scientific‐integrity abuses provokes concerted pressure by the scientific community, leading to efforts to improve scientific‐integrity protections under a new administration. However, protections are often inconsistently applied and are at risk of reversal under administrations publicly hostile to evidence‐based policy. We compared recent challenges to scientific integrity to determine what aspects of scientific input into conservation policy are most at risk of political distortion and what can be done to strengthen safeguards against such abuses. To ensure the integrity of outbound communications from government scientists to the public, we suggest governments strengthen scientific integrity policies, include scientists’ right to speak freely in collective‐bargaining agreements, guarantee public access to scientific information, and strengthen agency culture supporting scientific integrity. To ensure the transparency and integrity with which information from nongovernmental scientists (e.g., submitted comments or formal policy reviews) informs the policy process, we suggest governments broaden the scope of independent reviews, ensure greater diversity of expert input and transparency regarding conflicts of interest, require a substantive response to input from agencies, and engage proactively with scientific societies. For their part, scientists and scientific societies have a responsibility to engage with the public to affirm that science is a crucial resource for developing evidence‐based policy and regulations in the public interest.     

Health risk assessment of potentially harmful elements and dietary minerals from vegetables irrigated with untreated wastewater,Pakistan

In the developing world, vegetables are commonly grown in suburban areas irrigated with untreated wastewater containing potentially harmful elements (PHEs). In Pakistan, there is no published work on the bioaccessibility aspect of PHEs and dietary minerals (DMs) in sewage-irrigated soil or the vegetables grown on such soils in Pakistan. Several industrial districts of Pakistan were selected for assessment of the risk associated with the ingestion of vegetables grown over sewage-irrigated soils. Both the total and bioaccessible fraction of PHEs (Cd, Co, Cr, Ni, and Pb) and DMs (Fe, Cu, Mn, Zn, Ca, Mg, and I) in soils and vegetable samples were measured. The concentrations of these PHEs and DMs in sewage-irrigated and control soils were below published upper threshold limits. However, compared to control soils, sewage irrigation over the years decreased soil pH (7.7 vs 8.1) and enhanced dissolved organic carbon (1.8 vs 0.8 %), which could enhance the phyto-availability of PHEs and DMs to crops. Of the PHEs and DMs, the highest transfer factor (soil to plant) was noted for Cd and Ca, respectively. Concentrations of PHEs in most of the sewage-irrigated vegetables were below the published upper threshold limits, except for Cd in the fruiting portion of eggplant and bell pepper (0.06–0.08 mg/kg Cd, dry weight) at three locations in Gujarat and Kasur districts. The bioaccessible fraction of PHEs can reduce the context of dietary intake measurements compared to total concentrations, but differences between both measurements were not significant for Cd. Since the soils of the sampled districts are not overly contaminated compared to control sites, vegetables grown over sewage-irrigated soils would provide an opportunity to harvest mineral-rich vegetables potentially providing consumers 62, 60, 12, 104, and 63 % higher dietary intake of Cu, Mn, Zn, Ca, and Mg, respectively. Based on Fe and vanadium correlations in vegetables, it is inferred that a significant proportion of total dietary Fe intake could be contributed by soil particles adhered to the consumable portion of vegetables. Faecal sterol ratios were used to identify and distinguish the source of faecal contamination in soils from Gujranwala, Gujarat, and Lahore districts, confirming the presence of human-derived sewage biomarkers at different stages of environmental alteration. A strong correlation of some metals with soil organic matter concentration was observed, but none with sewage biomarkers.     

Atrazine contamination in agricultural soils from the Yangtze River Delta of China and associated health risks

Atrazine is one of the most widely applied and persistent herbicides in the world. In view of limited information on the regional contamination of atrazine in soils in China, this study investigated the spatial distribution and environmental impacts of atrazine in agricultural soils collected from the Yangtze River Delta (YRD) as an illustrative analysis of rapidly developing regions in the country. The results showed that the concentrations of atrazine in the YRD agricultural soils ranged from <1.0 to 113 ng/g dry weight, with a mean of 5.7 ng/g, and a detection rate of 57.7 % in soils. Pesticide factory might be a major source for the elevated levels of atrazine in Zhejiang Province. The contamination of atrazine was closely associated with land use types. The concentrations and detection rates of atrazine were higher in corn fields and mulberry fields than in rice paddy fields. There was no significant difference in compositions of soil microbial phospholipids fatty acids among the areas with different atrazine levels. Positive relationship (R = 0.417, p < 0.05, n = 30) was observed between atrazine and total microbial biomass. However, other factors, such as soil type and land management practice, might have stronger influences on soil microbial communities. Human health risks via exposure to atrazine in soils were estimated according to the methods recommended by the US EPA. Atrazine by itself in all the soil samples imposed very low carcinogenic risks (<10^?6) and minimal non-cancer risks (hazard index <1) to adults and children.     

Climate anomalies, Indonesian vegetation fires and terrestrial carbon emissions

There was a widespread misconception about the causes of vegetation and land fires in Indonesia. At a certain point, the public perceived that fires and the associated haze pollution were primarily caused by smallholders' agricultural activities. In fact, there was a variety of land-use activities including large-scale land clearing following deforestation for further land development. El Niño events and the associated dry weather were sometimes quoted by officials and the media as the cause of fires. The fire episodes from 1980 to 2000 were analysed in connection with climate anomalies and the implementation of land-use policies related to forest conversions. The analysis employs long-term climatic and sea surface temperature data to reconstruct climate distributions and anomalies including Southern Oscillation Index (SOI), Sea Surface Temperature (SST) and Outgoing Long-wave Radiation (OLR). In this study, the terrestrial carbon emissions from vegetation fires were estimated based on official statistical data on area burnt. The possible incentives for sustainable land management were discussed in the light of fire prevention. The underlying cause neglected in the discussion of Indonesian vegetation fires was forest and land development policy. Legitimated in the early 1980s, it drove massive forest conversions and the use of fires for land clearing. El Niño Southern Oscillation (ENSO) provided dry weather suitable for biomass burning and widespread fire, but it was hardly the cause of fires. The estimate of area burnt in the big fires in 1997 was about 11.6 Mha, resulting in carbon release of 1.45 Gt, equivalent to 0.73 ppmv of CO₂, or almost half the annual global atmospheric CO₂ growth. Based on the current carbon market price such emissions by the 1997 fire episode were worth around US$ 3.6 billion.     

Effect of power plant emission reductions on a nearby wilderness area: a case study in northwestern Colorado

This study evaluates the effect of emission reductions at two coal-fired power plants in northwestern Colorado on a nearby wilderness area. Control equipment was installed at both plants during 1999–2004 to reduce SO₂ and NOx emissions. One challenge was separating the effects of local from regional emissions, which also declined during the study period. The long-term datasets examined confirm that emission reductions had a beneficial effect on air and water quality in the wilderness. Despite a 75 % reduction in SO₂ emissions, sulfate aerosols measured in the wilderness decreased by only 20 %. Because the site is relatively close to the power plants (<75 km), the slow rate of conversion of SO₂ to sulfate, particularly under conditions of low relative humidity, might account for this less than one-to-one response. On the clearest days, emissions controls appeared to improve visibility by about 1 deciview, which is a small but perceptible improvement. On the haziest days, however, there was little improvement perhaps reflecting the dominance of regional haze and other components of visibility degradation particularly organic carbon and dust. Sulfate and acidity in atmospheric deposition decreased by 50 % near the southern end of the wilderness of which 60 % was attributed to power plant controls and the remainder to reductions in regional sources. Lake water sulfate responded rapidly to trends in deposition declining at 28 lakes monitored in and near the wilderness. Although no change in the acid–base status was observed, few of the lakes appear to be at risk from chronic or episodic acidification.     

Species Distribution Models of Freshwater Stream Fishes in Maryland and Their Implications for Management

Species distribution models (SDMs) are often used in conservation planning, but their utility can be improved by assessing the relationships between environmental and species response variables. We constructed SDMs for 30 stream fishes of Maryland, USA, using watershed attributes as environmental variables and presence/absence as species responses. SDMs showed substantial agreement between observed and predicted values for 17 species. Most important variables were natural attributes (e.g., ecoregion, watershed area, latitude/longitude); land cover (e.g., %impervious, %row crop) was important for three species. Focused analyses on four representative species (central stoneroller, creek chub, largemouth bass, and white sucker) showed the probability of presence of each species increased non-linearly with watershed area. For these species, SDMs built to predict absent, low, and high densities were similar to presence/absence predictions but provided probable locations of high densities (e.g., probability of high-density creek chub decreased rapidly with watershed area). We applied SDMs to predict suitability of watersheds within the study area for each species. Maps of suitability and the environmental and species response relationships can help develop better management plans.     

Evaluation of concentration efficiency of the Pseudomonas aeruginosa phage PP7 in various water matrixes by different methods

Enteric viruses monitoring in surface waters requires the concentration of viruses before detection assays. The aim of this study was to evaluate different methods in terms of recovery efficiencies of bacteriophage PP7 of Pseudomonas aeruginosa, measured by real-time PCR, using it as a viral control process in water analysis. Different nucleic acid extraction methods (silica–guanidinium thiocyanate, a commercial kit (Qiagen Viral RNA Kit) and phenol–chloroform with alcohol precipitation) exhibited very low recovery efficiencies (0.08–4.18 %), being the most efficient the commercial kit used for subsequent experiments. To evaluate the efficiency of three concentration methods, PBS (as model for clean water) and water samples from rivers were seeded to reach high (HC, 10⁶ pfu ml^?1) and low concentrations (LC, 10⁴ pfu ml^?1) of PP7. Tangential ultrafiltration proved to be more efficient (50.36?±?12.91, 17.21?±?9.22 and 12.58?±?2.35 % for HC in PBS and two river samples, respectively) than adsorption–elution with negatively charged membranes (1.00?±?1.34, 2.79?±?2.62 and 0.05?±?0.08 % for HC in PBS and two river samples, respectively) and polyethylene glycol precipitation (15.95?±?7.43, 4.01?±?1.12 and 3.91?±?0.54 %, for HC in PBS and two river samples, respectively), being 3.2–50.4 times more efficient than the others for PBS and 2.7–252 times for river samples. Efficiencies also depended on the initial virus concentration and aqueous matrixes composition. In consequence, the incorporation of an internal standard like PP7 along the process is useful as a control of the water concentration procedure, the nucleic acid extraction, the presence of inhibitors and the variability of the recovery among replicas, and for the calculation of the sample limit of detection. Thus, the use of a process control, as presented here, is crucial for the accurate quantification of viral contamination.