Evaluating Flow Metric‐Based Stream Classification Systems to Support the Determination of Ecological Flows in North Carolina

Hydroecological classification systems are typically based on an assemblage of streamflow metrics and seek to divide streams into ecologically relevant classes. Assignment of streams to classes is suggested as an initial step in the process of establishing ecological flow standards. We used two distinct hydroecological river classification systems available within North Carolina to evaluate the ability of a hydrologic model to assign the same classes as those determined by observed streamflows and to assess the transferability of such systems to ungaged streams. Class assignments were examined by rate of overall matches, rate of class matches, spatial variability in matches, and time period used in class assignment. The findings of this study indicate assignments of stream class: (1) are inconsistent among different classification systems; (2) differ between observed and modeled data; and (3) are sensitive to the period of record within observed data. One clear source of inconsistency/sensitivity in class assignments lies with the use of threshold values for metrics that distinguish stream classes, such that even small changes in metric values can result in different class assignments. Because these two hydroecological classification systems are representative of other classification systems that rely on quantitative decision thresholds, it can be surmised that the use of such systems based on stream flow metrics is not a reliable approach for guiding ecological flow determinations.     

INPUTS OF COPPER‐BASED CROP PROTECTANTS TO COASTAL CREEKS FROM PASTICULTURE RUNOFF1

ABSTRACT: Inputs of copper‐based crop protectants from tomato fields grown under plastic mulch agriculture (plasticulture) to an estuarine creek were investigated. Copper was measured in runoff from diverse land‐uses including conventional agriculture, plasticulture, residences, and natural areas. Water column and sediment copper concentrations were measured in plasticulture and control (nonagriculture) watersheds. Copper concentrations in plasticulture‐impacted creeks exceeded background levels episodically. High concentrations occurred during or immediately after runoff‐producing rains. Concentrations of 263 μg/L total copper and 126 μg/L dissolved copper were measured in a tidal creek affected by plasticulture; concentrations exceeded the shellfish LC₅₀ values and the water quality criteria of 2.9 μg/L dissolved copper. Control watersheds indicated background water column levels of ≤ 4 μg/L dissolved copper with similar copper levels during periods with and without rain. The copper concentrations in tomato plasticulture field runoff itself contained up to 238 μg/L dissolved copper. Copper concentrations in runoff from other land‐uses were less than 5 μg/L dissolved copper. Creek sediment samples adjacent to a plasticulture field contained significantly higher copper concentrations than sediments taken from nonplasticulture watersheds.     

Sources and Distribution of Polychlorinated Terphenyls at a Major US Aeronautics Research Facility

O -deethylase (EROD) activity to a similar degree as PCB Aroclor 1254 and to a greater extent than PCT Aroclor 5460. The presence of high concentrations of PCTs contributed to the facility being included on the National Priorities List. It subsequently became the first US federal facility to sign a Federal Facility Agreement, identifying cleanup responsibilities, prior to formal listing.     

Quantifying ‘geographic proximity’: Experiences from the United Kingdom's National Industrial Symbiosis Programme

Geographic proximity is said to be a key characteristic of the resource reuse and recycling practice known as industrial symbiosis. To date, however, proximity of symbiont companies has remained an abstract characteristic. By conducting a statistical analysis of synergies facilitated by the United Kingdom's National Industrial Symbiosis Programme during their first five years of operation, this article attempts to quantify geographic proximity and in the process provide practitioners with an insight into the movement trends of different waste streams. Among other it was found that the median distance materials travelled within a symbiotic relationship is 20.4 miles. It is argued that quantitative information of this form is of practical value for the effective deployment of industrial symbiosis practitioners and wider resource efficiency planning. The results and discussion presented within this article are specific to industrial symbiosis opportunities facilitated within the United Kingdom; the methodology and assessment of resource movement influences are, however, expected to be relevant to all countries in which industrial activity is similarly mature and diversified.     

The typography of environmental impact statements: Criteria,evaluation, and public participation

Guidelines for implementation of the National Environmental Policy Act state that environmental impact statements (EISs) shall use “appropriate graphics.” We examined one component of graphics, typography, identifying applicable criteria from the literature and applying them to 150 EISs prepared by seven agencies. We found that the EISs ranged widely in typographic quality. The average EIS met fewer than seven of ten criteria; 12% were considered unreadable. The results suggest that weak typography may seriously limit public review of EISs. Agencies are encouraged to make typography a serious component of their public participation programs.     

Physical limitations and musculoskeletal complaints associated with work in unusual or restricted postures: a literature review

INTRODUCTION: The vast majority of ergonomics research has addressed the demands of work in standing or sitting postures, and understandably so. However, many workers (e.g., underground miners, aircraft baggage handlers, plumbers, agricultural workers, mechanics, and others) are often required to adopt postures such as kneeling, stooping, squatting, or lying down for significant periods of the workday. METHOD: A literature search was performed using the ISI Web of Science database (for years 1980-2004). Articles retrieved from this search were evaluated in terms of relevance to assessing physical capabilities of workers in these postures and/or the musculoskeletal epidemiology associated with these postures. RESULTS: Work in unusual and restricted postures was associated with significantly higher rates of musculoskeletal complaints compared to workers not adopting these postures in epidemiology studies (Odds Ratios ranging from 1.13 to 13). Some studies suggested a dose-response relationship, with longer exposures leading to increased musculoskeletal complaints. Physical strength and psychophysical lifting capacity vary significantly as unusual or restricted postures are adopted, with lower lifting capacities evident in the kneeling, squatting, and lying positions. CONCLUSIONS: Workers who adopt unusual or restricted postures appear to be at higher risk of musculoskeletal complaints and often exhibit reduced strength and lifting capacity. Research needs in this area include improved exposure assessment tools, studies of intervention effectiveness, adaptations of the body in response of work in unusual postures, and elucidation of relevant injury pathways. IMPACT ON INDUSTRY: Workers who adopt unusual or restricted postures in their work often experience higher musculoskeletal injury rates. If awkward postures cannot be eliminated in the workplace, jobs should be designed in accordance with the reduced strength and lifting capabilities observed in these postures.     

Spatial variation in dimethylsulfoniopropionate (DMSP) production in <Emphasis Type="Italic">Ulva lactuca</Emphasis> (Chlorophyta) from the Northeast Pacific

Although dimethylsulfoniopropionate (DMSP) has a variety of functions in marine macroalgae including that of a cryoprotectant, an osmolyte, a way to remove excess sulfur and energy, an antioxidant, and an allelopathic precursor, the latter two functions are believed to be the most important in Ulva lactuca L. (=U. fenestrata) in intertidal populations on the coast of Washington state, USA. The present study found significant variation in DMSP concentrations among U. lactuca collected in May 2005 from six sites ranging from 47°54.45′N (Possession Point, Whidbey Island, WA, USA) to 48°30.55′N (Shannon Point Beach, Anacortes, WA, USA), and also among individuals within sites, and among tissues (basal tissues near the holdfast, middle of the blades, and tips). Concentrations ranged from 37 to 224 μmol g⁻¹ fresh mass (FM). In several 10-day experiments between July 2001 and August 2004 with U. lactuca collected from several places on the coast of Washington, the effects of nutrient level (DIN), light intensity and wavelength, and grazing by the herbivorous gastropod Lacuna vincta, were examined. None of these manipulations resulted in DMSP concentrations that differed significantly from controls, and variance in DMSP concentrations within each experiment was very low. Although DMSP concentrations in U. lactuca may be affected by factors not tested in these experiments, it is also possible that the observed spatial differences reflect constitutive genotypic or phenotypic differences among geographically separated U. lactuca populations or among cryptic Ulva species. Electronic supplementary material Supplementary material is available in the online version of this article at and is accessible for authorized users.     

Consequences of ignoring dispersal variation in network models for landscape connectivity

Habitat loss and fragmentation can negatively influence population persistence and biodiversity, but the effects can be mitigated if species successfully disperse between isolated habitat patches. Network models are the primary tool for quantifying landscape connectivity, yet in practice, an overly simplistic view of species dispersal is applied. These models often ignore individual variation in dispersal ability under the assumption that all individuals move the same fixed distance with equal probability. We developed a modeling approach to address this problem. We incorporated dispersal kernels into network models to determine how individual variation in dispersal alters understanding of landscape-level connectivity and implemented our approach on a fragmented grassland landscape in Minnesota. Ignoring dispersal variation consistently overestimated a population's robustness to local extinctions and underestimated its robustness to local habitat loss. Furthermore, a simplified view of dispersal underestimated the amount of habitat substructure for small populations but overestimated habitat substructure for large populations. Our results demonstrate that considering biologically realistic dispersal alters understanding of landscape connectivity in ecological theory and conservation practice.     

Spatiotemporal Variability of Snow Depletion Curves Derived from SNODAS for the Conterminous United States, 2004‐2013

Assessment of water resources at a national scale is critical for understanding their vulnerability to future change in policy and climate. Representation of the spatiotemporal variability in snowmelt processes in continental‐scale hydrologic models is critical for assessment of water resource response to continued climate change. Continental‐extent hydrologic models such as the U.S. Geological Survey National Hydrologic Model (NHM) represent snowmelt processes through the application of snow depletion curves (SDCs). SDCs relate normalized snow water equivalent (SWE) to normalized snow covered area (SCA) over a snowmelt season for a given modeling unit. SDCs were derived using output from the operational Snow Data Assimilation System (SNODAS) snow model as daily 1‐km gridded SWE over the conterminous United States. Daily SNODAS output were aggregated to a predefined watershed‐scale geospatial fabric and used to also calculate SCA from October 1, 2004 to September 30, 2013. The spatiotemporal variability in SNODAS output at the watershed scale was evaluated through the spatial distribution of the median and standard deviation for the time period. Representative SDCs for each watershed‐scale modeling unit over the conterminous United States (n = 54,104) were selected using a consistent methodology and used to create categories of snowmelt based on SDC shape. The relation of SDC categories to the topographic and climatic variables allow for national‐scale categorization of snowmelt processes.