Shark recreational fisheries: Status,challenges, and research needs

For centuries, the primary manner in which humans have interacted with sharks has been fishing. A combination of their slow-growing nature and high use-values have resulted in population declines for many species around the world, and to date the vast majority of fisheries-related work on sharks has focused on the commercial sector. Shark recreational fishing remains an overlooked area of research despite the fact that these practices are popular globally and could present challenges to their populations. Here we provide a topical overview of shark recreational fisheries, highlighting their history and current status. While recreational fishing can provide conservation benefits under certain circumstances, we focus our discourse on the relatively understudied, potentially detrimental impacts these activities may have on shark physiology, behavior, and fitness. We took this angle given the realized but potentially underestimated significance of recreational fishing for shark conservation management plans and stock assessments, in hopes of creating a dialogue around sustainability. We also present a series of broad and focused research questions and underpin areas of future research need to assist with the development of this emergent area of research.     

Performance evaluation of an in situ source area combined remedy for the remediation of commingled chlorinated ethanes and ethenes

The chlorinated volatile organic compounds (CVOCs), tetrachloroethene (PCE), trichloroethene (TCE), and 1,1,1‐trichloroethane (1,1,1‐TCA), often found as commingled contaminants of concern (COCs) in groundwater, can degrade via a variety of biotic and abiotic reductive pathways. In situ remediation of a groundwater contaminant source area containing commingled 1,1,1‐TCA, PCE, and TCE was conducted using a combined remedy/treatment train approach. The first step was to create geochemically reducing conditions in the source area to degrade the CVOCs to lesser chlorinated CVOCs (i.e., 1,1‐dichloroethane [1,1‐DCA], 1,1‐dichlorethene [1,1‐DCE], cis‐1,2‐dichoroethene [cis‐1,2‐DCE], and vinyl chloride [VC]) via enhanced reductive dechlorination (ERD). Carbon substrates were injected to create microbial‐induced geochemically reducing conditions. An abiotic reductant (zero‐valent iron [ZVI]) was also used to further degrade the CVOCs, minimizing the generation of 1,1‐DCE and VC, and co‐precipitate temporarily mobilized metals. An in situ aerobic zone was created downgradient of the treatment zone through the injection of oxygen. Remaining CVOC degradation products and temporarily mobilized metals (e.g., iron and manganese) resulting from the geochemically reducing conditions were then allowed to migrate through the aerobic zone. Within the aerobic zone, the lesser chlorinated CVOCs were oxidized and the solubilized metals were precipitated out of solution. The injection of a combination of carbon substrates and ZVI into the groundwater system at the site studied herein resulted in the generation of a geochemically reducing subsurface treatment zone that has lasted for more than 4.5 years. Mass concentrations of total CVOCs were degraded within the treatment zone, with near complete transformation of chlorinated ethenes and a more than 90 percent reduction of CVOC mass concentrations. Production of VC and 1,1‐DCE has been minimized through the combined effects of abiotic and biological processes. CVOC concentrations have declined over time and temporarily mobilized metals are precipitating out of the dissolved phase. Precipitation of the dissolved metals was mitigated using the in situ oxygenation system, also resulting in a return to aerobic conditions in downgradient groundwater. Chloroethane (CA) is the dominant CVOC degradation product within the treatment zone and downgradient of the treatment zone, and it is expected to continue to aerobically degrade over time. CA did not accumulate within and near the aerobic oxygenation zone. The expectations for the remediation system are: (1) the concentrations of CVOCs (primarily in the form of CA) will continue to degrade; (2) total organic carbon concentrations will continue to decline to pre‐remediation levels; and, (3) the groundwater geochemistry will experience an overall trend of transitioning from reducing back to pre‐remediation mildly oxidizing conditions within and downgradient of the treatment zone.     

In Situ Measurement of Hydrochloric Acid in Rocket Exhaust Clouds Using a Remotely Piloted Aircraft

Abstract

An instrumentation system employing an RPV (remotely piloted vehicle) platform was developed for temporally and spatially resolved air pollution measurements, and was used to measure the evolution of gas-phase HC1 in exhaust clouds from a solid rocket motor firing and fuel pit burns. A thermistor and a sensitive (ppmv-level), rapid-response (<0.1 sec) infrared absorption sensor for HC1 were mounted in a flow channel in the RPV, permitting concentration and temperature measurements to be made in the cloud on a several-meter scale. The RPV system was flown in a series of field tests at Thiokol Corporation’s Elkton, MD division to evaluate the HC1 content of the exhaust products of a new Mg-based fuel formulation. Measurements were made in the clouds from Al-based and Mg-based solid fuel pit burns and a Mg-fueled motor firing over periods of several minutes. Elevated temperatures and HC1 concentrations were found to be temporally correlated with video images of the particulate cloud. Cl originating from the ammonium perchlorate oxidizer appeared in the exhaust as HC1 in each of the tests. Both the macroscopic and local cloud parameters indicate that the Mg-based fuel may provide some reduction in HC1 concentration compared to the standard Al-based fuel.     

The Relationship between Historic Industrial Site Use and Environmental Contamination

ABSTRACT

A methodology is presented for estimating the probability that particular classes of environmental contaminants will be of concern at brownfield redevelopment sites. These probabilities are predicted by a logistics model that is based on qualitative information about site history and status. This qualitative information comprises data that would be collected through a Phase I Environmental Site Assessment (ESA), including historic site use, current use and ownership status, and the nature of adjacent properties. The model is fit and demonstrated using a set of 59 former industrial sites in southwestern Pennsylvania that were collected from the files of the Pennsylvania Department of Environmental Protection (PADEP). Predictive models are developed for exceedances of contaminants as grouped into the following classes: metals, chlorinated hydrocarbons, fuel hydrocarbons, and PCBs. A procedure for estimating the parametric uncertainty of the model predictions is also illustrated. This method can serve as a starting point for more effective usage of existing Phase I ESA information and for evaluation of the benefit of obtaining additional site information. By increasing the decision-making value of existing (or inexpensive) data, this method can help to reduce the information asymmetry that may be an obstacle to redevelopment.     

Climate Skepticism in British Newspapers, 2007–2011

Climate skepticism in the UK media has not been a major focus of recent research. This paper aims to help fill the gap by looking at the incidence of skeptical voices in UK newspapers across three periods: 2007, 2009/2010, and 2010/2011. After analyzing more than 3200 articles, it finds that skeptical voices increased their presence markedly across all newspapers and all types of articles in the second period, and maintained a significant presence in many in the third. Uncontested skeptical voices were particularly prevalent in opinion pieces and editorials in right-leaning newspapers in the second. It also finds that skeptical voices or opinions were more likely to be included in pieces written by in-house non-specialist columnists than by environment editors or correspondents. The negative implications of the results for public understanding and the quality of public debate are then explored.     

Extricating Membership as a PRP at Hazardous Waste Disposal Sites

Corporations often become potentially responsible parties (PRPs) at hazardous waste sites because of their past transportation or disposal of hazardous substances at such sites. Determining a PRP's potential liability for the assessment and cleanup of hazardous waste sites is a challenging effort and often results in disputes among other PRPs regarding appropriate allocation of response action costs to each party. Further, public companies have an obligation to report probable and reasonably estimable costs under Generally Accepted Accounting Principles (GAAP) for environmental liabilities at their current or prior hazardous waste sites. The first step in such an evaluation is to determine whether or not a PRP can extricate themselves from any association with the subject site or, alternatively, demonstrate de minimis status. This article describes the methods by which PRPs can extricate themselves from liability associated with response action costs at contaminated sites, including: evaluating a PRP's prior settlements or indemnifications with other PRPs; identifying insurance coverage or other financial assurance instruments for the disposal facility; and examining applicable statutes of limitations against when a PRP received notification from the regulatory agency. The article also presents a case study discussing how a PRP with a portfolio of 72 hazardous waste disposal sites was able to extricate itself from the majority of these sites, resulting in only four sites where the PRP was determined to be a PRP and where an associated allocable share was assigned. © 2014 Wiley Periodicals, Inc.     

Using the 'protective environment' framework to analyse children's protection needs in Darfur

A major humanitarian concern during the continuing crisis in Darfur, Sudan, has been the protection of children, although there has been little in the way of comprehensive analysis to guide intervention. Founded on a situational analysis conducted between October 2005 and March 2006, this paper documents the significant threats to children's well-being directly linked to the political conflict. It demonstrates the role of non-conflict factors in exacerbating these dangers and in promoting additional protection violations, and it uses the 'protective environment' framework (UNICEF Sudan, 2006a) to identify systematic features of the current environment that put children at risk. This framework is shown to provide a coherent basis for assessment and planning, prompting broad, multidisciplinary analysis, concentrating on preventive and protective action, and fostering a systemic approach (rather than placing an undue focus on the discrete needs of 'vulnerable groups'). Constraints on its present utility in emergency settings are also noted.     

Outdoor air pollution in close proximity to a continuous point source

Data are lacking on human exposure to air pollutants occurring in ground-level outdoor environments within a few meters of point sources. To better understand outdoor exposure to tobacco smoke from cigarettes or cigars, and exposure to other types of outdoor point sources, we performed more than 100 controlled outdoor monitoring experiments on a backyard residential patio in which we released pure carbon monoxide (CO) as a tracer gas for continuous time periods lasting 0.5–2 h. The CO was emitted from a single outlet at a fixed per-experiment rate of 120–400 cc min^?1 (～140–450 mg min^?1). We measured CO concentrations every 15 s at up to 36 points around the source along orthogonal axes. The CO sensors were positioned at standing or sitting breathing heights of 2–5 ft (up to 1.5 ft above and below the source) and at horizontal distances of 0.25–2 m. We simultaneously measured real-time air speed, wind direction, relative humidity, and temperature at single points on the patio. The ground-level air speeds on the patio were similar to those we measured during a survey of 26 outdoor patio locations in 5 nearby towns. The CO data exhibited a well-defined proximity effect similar to the indoor proximity effect reported in the literature. Average concentrations were approximately inversely proportional to distance. Average CO levels were approximately proportional to source strength, supporting generalization of our results to different source strengths. For example, we predict a cigarette smoker would cause average fine particle levels of approximately 70–110 μg m^?3 at horizontal distances of 0.25–0.5 m. We also found that average CO concentrations rose significantly as average air speed decreased. We fit a multiplicative regression model to the empirical data that predicts outdoor concentrations as a function of source emission rate, source–receptor distance, air speed and wind direction. The model described the data reasonably well, accounting for ～50% of the log-CO variability in 5-min CO concentrations.     

Effects of decadal exposure to interacting elevated CO2 and/or O3 on paper birch (Betula papyrifera) reproduction

We studied the effects of long-term exposure (nine years) of birch (Betula papyrifera) trees to elevated CO(2) and/or O(3) on reproduction and seedling development at the Aspen FACE (Free-Air Carbon Dioxide Enrichment) site in Rhinelander, WI. We found that elevated CO(2) increased both the number of trees that flowered and the quantity of flowers (260% increase in male flower production), increased seed weight, germination rate, and seedling vigor. Elevated O(3) also increased flowering but decreased seed weight and germination rate. In the combination treatment (elevated CO(2)+O(3)) seed weight is decreased (20% reduction) while germination rate was unaffected. The evidence from this study indicates that elevated CO(2) may have a largely positive impact on forest tree reproduction and regeneration while elevated O(3) will likely have a negative impact.     

Chronic toxicity of tributyltin to development and reproduction of the European freshwater snail Lymnaea stagnalis (L.)

Chronic toxicity, growth and reproduction were measured in the freshwater gastropod Lymnaea stagnalis exposed to waterborne bis(tri-n-butyltin) oxide (TBTO) over a range of four nominal concentrations (0-10microg TBTl(-1)). Egg development was completely inhibited at 10microg TBTl(-1), whilst abnormal embryonic development was observed at 1microg TBTl(-1). For the solvent control and the 0.01microg TBTl(-1)treatment group, normal development of L. stagnalis was observed. Survivorship of hatchlings was significantly reduced by TBT at 1microgl(-1) while inhibition of shell growth of L. stagnalis was also observed at this concentration. The data were used to determine intrinsic growth rates (r) using two theoretical approaches (the Euler-Lotka equation and a Leslie Matrix). Both approaches showed that survival, fecundity and population growth rate were reduced at 1microg TBTl(-1). Interestingly, at 0.01microg TBTl(-1) snails showed a higher fecundity and growth rate than in the solvent control. The TBT concentration at which the r would equal zero (ECr(0)) and the population NOEC (No Observed Effect Concentration) were estimated. The population NOEC was defined as either the lower 95% confidence or lower 95% pointwise percentile limit of the ECr(0). Values obtained using the two different approaches were similar and thus a geometric mean was calculated to obtain a final representative population NOEC value for L. stagnalis of 2745ng TBTl(-1). The present data together with chronic toxicity TBT data for freshwater organisms, obtained from peer-reviewed literature, were used to construct a species sensitivity distribution (SSD). A predicted no effect concentration was then derived from the SSD (hazardous concentration at 5%, i.e., HC5 or 95% protection level). This SSD was compared with the SSD derived from saltwater species datasets. The HC5 value for saltwater species (3.55ng TBTl(-1); lower confidence limit: 1.93ng TBTl(-1)) was significantly lower than that for freshwater species (30.13ng TBTl(-1); lower confidence limit: 9.23ng TBTl(-1)), indicating that saltwater species are probably more susceptible to TBT than their freshwater counterparts.