Effectiveness of emergent and submergent aquatic plants in mitigating a nitrogen–permethrin mixture

Hydraulically connected wetland microcosms (～50?L) in series were used to test the effectiveness of varying combinations of two common aquatic vascular plants, parrot feather (Myriophyllum aquaticum) and cattail (Typha latifolia), for mitigating contamination from a mixture of nitrogen (ammonium nitrate) and permethrin. The upstream series included Myriophyllum only (M) and Typha only (T) while the combination upstream effluent into downstream series included Myriophyllum into Myriophyllum (M?+?M) and Typha into Myriophyllum (T?+?M). During flow, M into M?+?M more efficiently mitigated nitrogen than T into T?+?M. Post-flow, nitrogen removal efficiency was greater for T versus M and M?+?M versus T?+?M. Mean aqueous dissipation half-lives (t_1/2) of NH₄-N and NO₃-N were more rapid in T than M treatments. Ammonium and nitrate t_1/2 was highly correlated with aquatic plant above-ground shoot biomass. Permethrin mitigation efficiencies and t_1/2 were not significantly affected by plant species either singly or in combination. Trans-permethrin t_1/2 was moderately correlated with plant biomass, but not cis-permethrin t_1/2. Results of this study indicate differences in aquatic plant species and flow path influence nitrogen removal but not permethrin. However, plant species appears less important than overall plant biomass in ascertaining aquatic plant effectiveness in mitigating a nitrogen–permethrin mixture.     

Fit-for-Purpose Institutions? An Evaluation of Biodiversity Conservation in the Agricultural Landscape of the Tasmanian Midlands,Australia

Biodiversity loss is a globally significant problem. Institutional failure to halt this loss suggests current arrangements are not fit for the purpose of conserving biodiversity. The objective of this paper is to diagnose institutional fitness for conserving biodiversity in the Tasmanian Midlands of Australia, a highly modified agricultural landscape with critically endangered biodiversity values. This paper presents and applies a novel diagnostic framework that adopts a broad view of institutional fit, drawing on concepts from adaptive governance, institutional theory, and public administration, and finds four areas of poor fit that can guide reform efforts. The first is a narrow framing of biodiversity objectives, leading to neglect of key social and ecological concerns. Second, the interplay of current arrangements fails to buffer key economic and political drivers, and compromises adaptive capacity. Third, limited government authority and embedded power relations raise questions about the effectiveness and fairness of current approaches. Finally, the reluctance of governments to devolve authority and decision-making powers to self-organizing networks constrains adaptation. This suite of fit problems constrains achievement of biodiversity conservation, particularly in dealing with landscape multifunctionality, the need to balance private landholder rights and responsibilities, and the need to consider how to respond to emerging novel and hybrid ecosystems.     

The Road to NHDPlus — Advancements in Digital Stream Networks and Associated Catchments

A progression of advancements in Geographic Information Systems techniques for hydrologic network and associated catchment delineation has led to the production of the National Hydrography Dataset Plus (NHDPlus). NHDPlus is a digital stream network for hydrologic modeling with catchments and a suite of related geospatial data. Digital stream networks with associated catchments provide a geospatial framework for linking and integrating water‐related data. Advancements in the development of NHDPlus are expected to continue to improve the capabilities of this national geospatial hydrologic framework. NHDPlus is built upon the medium‐resolution NHD and, like NHD, was developed by the U.S. Environmental Protection Agency and U.S. Geological Survey to support the estimation of streamflow and stream velocity used in fate‐and‐transport modeling. Catchments included with NHDPlus were created by integrating vector information from the NHD and from the Watershed Boundary Dataset with the gridded land surface elevation as represented by the National Elevation Dataset. NHDPlus is an actively used and continually improved dataset. Users recognize the importance of a reliable stream network and associated catchments. The NHDPlus spatial features and associated data tables will continue to be improved to support regional water quality and streamflow models and other user‐defined applications.     

A Rapid Method to Score Stream Reaches Based on the Overall Performance of Their Main Ecological Functions

A method was developed to score the ecological condition of first- to third-order stream reaches in the Auckland region of New Zealand based on the performance of their key ecological functions. Such a method is required by consultants and resource managers to quantify the reduction in ecological condition of a modified stream reach relative to its unmodified state. This is a fundamental precursor for the determination of fair environmental compensation for achieving no-net-loss in overall stream ecological value. Field testing and subsequent use of the method indicated that it provides a useful measure of ecological condition related to the performance of stream ecological functions. It is relatively simple to apply compared to a full ecological study, is quick to use, and allows identification of the degree of impairment of each of the key ecological functions. The scoring system was designed so that future improvements in the measurement of stream functions can be incorporated into it. Although the methodology was specifically designed for Auckland streams, the principles can be readily adapted to other regions and stream types.     

An analysis of injury claims from low-seam coal mines

Introduction

The restricted workspace present in low-seam coal mines forces workers to adopt awkward working postures (kneeling and stooping), which place high physical demands on the knee and lower back.

Method

This article provides an analysis of injury claims for eight mining companies operating low-seam coal mines during calendar years 1996-2008. All cost data were normalized using data on the cost of medical care (MPI) as provided by the U.S. Bureau of Labor Statistics.

Results

Results of the analysis indicate that the knee was the body part that led in terms of claim cost ($4.2 million), followed by injuries to the lower back ($2.7 million). While the average cost per injury for these body parts was $13,100 and $14,400, respectively (close to the average cost of an injury overall), the high frequency of these injuries resulted in their pre-eminence in terms of cost. Analysis of data from individual mining companies suggest that knee and lower back injuries were a consistent problem across companies, as these injuries were each among the top five most costly part of body for seven out of eight companies studied.

Application/Impact

Results of this investigation suggest that efforts to reduce the frequency of knee and low back injuries in low-seam mines have the potential to create substantial cost savings.     

Application and evaluation of the neutral red retention (NRR) assay for lysosomal stability in mussel populations along the Iberian Mediterranean coast

The neutral red retention (NRR) assay to determine lysosomal membrane stability (LMS) was applied to wild mussels (Mytilus galloprovincialis) sampled from fourteen sites with different degrees of chemical pollution along the Iberian Mediterranean coast in 2002 and 2003. Total body burdens for a range of contaminants were measured in pooled samples (n = 50) of whole soft tissues in order to explore possible causality. Mean LMS values (n = 15) were significantly greater in mussels from one of the selected two reference sites (San Diego) than in chemically well-characterized hotspot sites. Mean LMS values were inversely correlated with contaminant concentrations in mussel tissues (except for Zn). The multidimensional scaling ordination technique classified the sampling sites into three groups according to their chemical-physical-biological similarities and the results were statistically confirmed using ANOSIM analysis. The results show that lysosomal stability is an effective indicator of health status in mussels along the Iberian Mediterranean coast and that it is related to body burden of contaminants, particularly polycyclic aromatic hydrocarbons (PAHs) and polychlorinated biphenyls (PCBs).     

Assessing urban runoff program progress through a dry weather hybrid reconnaissance monitoring design

Characterizing dry weather conditions in urban Municipal Separate Storm Sewer Systems (MS4s), and then prioritizing and addressing problems due to urban pollutants, is a daunting challenge. The size and complexity of most MS4s and the ephemeral nature of many dry weather problems hamper efforts to identify and eliminate pollutant sources, and to track trends in condition. As a result, assessing overall program progress has proven difficult. We describe a hybrid dry weather urban monitoring design from southern California that combines probabilistic and targeted sampling to rigorously identify and prioritize problems and track program progress. Data from probabilistic sites define the urban background and establish tolerance intervals, which identify sites that persistently exceed the overall urban background. Targeted sites focus on locations where nearby activities and/or past history suggest that pollutant levels will be elevated. Embedding targeted monitoring within a probabilistic design enables data from targeted sites to be interpreted in a more meaningful regional context. Data from all sites are also used to construct site- and pollutant-specific control charts. These charts quickly identify instances where a site's behavior significantly changes, compared to its past behavior, suggesting an active source in the upstream drainage area. The hybrid design, and the use of formal statistical tools (tolerance intervals and control charts), permit the program to systematically prioritize problematic sites, compare conditions to the regional urban background, and track trends over time. In addition, the program's design allows several measures of program progress to be defined and thus consistently followed over time. Such hybrid designs can provide substantial advantages compared to more traditional monitoring approaches.     

A long-term monitoring study of chlorophyll,microbial contaminants,and pesticides in a coastal residential stormwater pond and its adjacent tidal creek

Stormwater ponds are commonly used in residential and commercial areas to control flooding. The accumulation of urban contaminants in stormwater ponds can lead to water-quality problems including nutrient enrichment, chemical contamination, and bacterial contamination. This study presents 5 years of monitoring data assessing water quality of a residential subdivision pond and adjacent tidal creek in coastal South Carolina, USA. The stormwater pond is eutrophic, as described by elevated concentrations of chlorophyll and phosphorus, and experiences periodic cyanobacterial blooms. A maximum monthly average chlorophyll concentration of 318.75 μg/L was measured in the stormwater pond and 227.63 μg/L in the tidal creek. Fecal coliform bacteria (FCB) levels were measured in both the pond and the tidal creek that exceeded health and safety standards for safe recreational use. A maximum monthly average FCB level of 1,247 CFU/100 mL was measured in the stormwater pond and 12,850 CFU/100 mL in the tidal creek. In addition, the presence of antibiotic resistant bacteria and pathogenic bacteria were detected. Low concentrations of herbicides (atrazine and 2,4-D), a fungicide (chlorothalonil), and insecticides (pyrethroids and imidacloprid) were measured. Seasonal trends were identified, with the winter months having the lowest concentrations of chlorophyll and FCB. Statistical differences between the stormwater pond and the tidal creek were also noted within seasons. The tidal creek had higher FCB levels than the stormwater pond in the spring and summer, whereas the stormwater pond had higher chlorophyll levels than the tidal creek in the summer and fall seasons. Chlorophyll and FCB levels in the stormwater pond were significantly correlated with monthly average temperature and total rainfall. Pesticide concentrations were also significantly correlated with temperature and rainfall. Pesticide concentrations in the stormwater pond were significantly correlated with pesticide concentrations in the adjacent tidal creek. Chlorophyll and FCB levels in the tidal creek, however, were not significantly correlated with levels in the pond. While stormwater ponds are beneficial in controlling flooding, they may pose environmental and human health risks due to biological and chemical contamination. Management to reduce residential runoff may improve water quality in coastal stormwater ponds and their adjacent estuarine ecosystems.     

The Collection and Analysis of Inorganic Dust Downwind of Source Effluents

Two directionally oriented high-volume samplers are used to pinpoint the collection of specific inorganic dusts from an industrial emission. One of the samplers is placed upwind of the source, and the other downwind. Both samplers are activated by winds blowing from the direction of the source to the downwind sampler. Both are de-activated when the wind shifts from the 30° sampling arc. Thus, the upwind sampler “sees” background dust, and the downwind sampler “sees” material originating from the source. Microsorban filters are used to collect the dust materials. The filter is then dissolved in benzene and the residue washed with benzene to remove the filter material and organic substances collected. The residue consists of dry, inorganic dust, which is then subjected to X-ray diffraction and optical microscopy, for analysis. This technique was successfully used to collect and analyze cement dust and mica dust from two separate industrial sources. The technique has promise for the analysis of a wide variety of inorganic materials which can be identified by X-ray diffraction, optical microscopy or other techniques.