Status of Piping Plovers in the Great Plains of North America: A Demographic Simulation Model

A stochastic population growth model using empirical demographic data confirmed that the Piping Plover population of the Great Plains of North America is declining by more than 7% annually. Unchecked, this decline would result in extirpation in approximately 80 years. When recent adult (0.66) and immature (0.60) survival rates were held constant, a 31% increase—from 0.86 to 1.13 chicks fledged per pair—was needed to stabilize the population. Annual population increases of 1% and 2% required 1.16 and 1.19 chicks per pair, respectively. Such growth would result in the Great Plains population reaching the level—(2550 pairs)—needed for delisting from the U.S. Endangered Species Act protection in 53 and 30 years, respectively. One- and five-year delays in the initiation of 1% population growth caused 13 and 67 year delays respectively in reaching recovery.     

The co-application of earthworms (Dendrobaena veneta) and compost to increase hydrocarbon losses from diesel contaminated soils

The feasibility of using composted civic waste for the remediation of a soil contaminated with petroleum hydrocarbons (extractable petroleum hydrocarbons (EPH) 10+/-1.8 g kg(-1) and total 16 USEPA PAH 1.62+/-0.5 g kg(-1)) was assessed. The effects of compost to soil ratio, in combination with and without earthworm presence (Dendrobaena veneta), upon the loss of contaminants were determined for EPH (GC-FID) and PAH (GC-MS), respectively. Increasing the ratio of compost substrate to hydrocarbon impacted soil (1:0.5, 1:1, 1:2 and 1:4 (soil:compost wt/wt)) in the absence of earthworms resulted in significantly (p<0.05) greater losses of both EPH and SigmaPAH after an 84 d incubation period, when compared to the soil only control. Where earthworms were present without compost, EPH losses were significantly (p<0.05) enhanced in the soil only treatment (33.4+/-5.3% residual) compared to the soil only control (54.4+/-5.3% residual). However, PAH loss in the soil only treatment (with-earthworm presence) were only slightly enhanced (65.3+/-9.3% residual), with respect to the soil only control (69.2+/-6.4% residual). Synergistic benefits of both earthworm and compost presence were most significant for PAHs (p<0.05), and less so for EPH. (14)C-respirometer studies, to establish catabolic competence in terms of microbial mineralisation of key hydrocarbons, complemented the hydrocarbon analysis.     

What can water utilities do to improve risk management within their business functions? An improved tool and application of process benchmarking

We present a model for benchmarking risk analysis and risk based decision making practice within organisations. It draws on behavioural and normative risk research, the principles of capability maturity modelling and our empirical observations. It codifies the processes of risk analysis and risk based decision making within a framework that distinguishes between different levels of maturity. Application of the model is detailed within the selected business functions of a water and wastewater utility. Observed risk analysis and risk based decision making practices are discussed, together with their maturity of implementation. The findings provide academics, utility professionals, and regulators a deeper understanding of the practical and theoretical underpinnings of risk management, and how distinctions can be made between organisational capabilities in this essential business process.     

HERBICIDE CONTAMINATION BY THE 1993 GREAT FLOOD ALONG THE MISSISSIPPI RWER1

ABSTRACT: The Great Flood of 1993 inundated more than 355,000 ha of illinois cropland, creating great concern for the possible contamination of farmland by herbicides. The objective of this study was to assess the herbicide contamination of floodwaters and farmland due to the great flood of 1993. Floodwater samples were collected between August 5 and December 20, 1993, at the Horseshoe Lake State Game Reserve in Alexander County, Illinois, USA. Water and suspended sediment were tested separately for the more commonly used herbicides in Illinois and the midwestern USA: alachior, atrazine, and cyanazine. These herbicides were detected in the floodwater samples, but concentrations were all below the health advisory concentration of 3 μg/L established for drinking water by the United States Environmental Protection Agency. No herbicides were detected in the suspended sediment. After the recession of the flood, soil samples from flooded and non-flooded corn fields were collected for comparison. Soil samples taken from two out of three sampling locations had a 0.4 to 0.8 μg/kg increase in atrazine at the flooded verses the non-flooded sites. Concentrations were 500 to 1,000 times lower than the recommended 1 mg/kg rate at which this herbicides typically applied to soil.     

Limitations of Captive Breeding in Endangered Species Recovery

The use of captive breeding in species recovery has grown enormously in recent years, but without a concurrent growth in appreciation of its limitations. Problems with (1) establishing self-sufficient captive populations, (2) poor success in reintroductions, (3) high costs, (4) domestication, (5) preemption of other recovery techniques, (6) disease outbreaks, and (7) maintaining administrative continuity have all been significant. The technique has often been invoked prematurely and should not normally be employed before a careful field evaluation of costs and benefits of all conservation alternatives has been accomplished and a determination made that captive breeding is essential for species survival. Merely demonstrating that a species' population is declining or has fallen below what may be a minimum viable size does not constitute enough analysis to justify captive breeding as a recovery measure. Captive breeding should be viewed as a last resort in species recovery and not a prophylactic or long-term solution because of the inexorable genetic and phenotypic changes that occur in captive environments. Captive breeding can play a crucial role in recovery of some species for which effective alternatives are unavailable in the short term. However, it should not displace habitat and ecosystem protection nor should it be invoked in the absence of comprehensive efforts to maintain or restore populations in wild habitats. Zoological institutions with captive breeding programs should operate under carefully defined conditions of disease prevention and genetic/behavioral management. More important, these institutions should help preserve biodiversity through their capacities for public education, professional training, research, and support of in situ conservation efforts.     

Mapping the intertidal vegetation of the harbours of southern England for water quality management

This paper discusses a research project dealing with the mapping of the intertidal vegetation of several harbours along the southern coastline of England. It describes in detail the methods used to map the vegetation and gives examples of the results from these studies. This paper then goes on to explain how these results are applied by the Environment Agency of England and Wales to improve water quality in the harbours. This type of vegetation mapping is useful in monitoring the development of the intertidal species includingSpartina, Zostera and of particular importance to this study the green algaeUlva andEnteromorpha. The work was undertaken with funding from the Environment Agency and at present has taken place over a four year period. The data collected will be used by the Environment Agency to assess macro-algae covervalues for the intertidal area of the harbours concerned. This forms part of the Agency's commitment to the EU Nitrates Directive and the Urban Waste Water Treatment Directive. Some of the species mapped act as suitable indicators of water quality and are symptoms of entrophication. Other species are of interest for nature conservation and were recorded to provide a record for longer-term trends in vegetation patterns within the harbour. This paper aims to provide readers with an understanding of the techniques involved as well as an evaluation of the methodology.     

The Prairie Dog and Biotic Diversity

Since the turn of this century, prairie dog populations have declined as much as 98% throughout North America, largely as a result of prairie dog eradication programs. The prairie dog is a keystone species that plays an important role in maintaining the biotic integrity of the western grasslands that stretch from southern Canada to northern Mexico. The fragmentation of prairie dog distribution has degraded diversity on those prairies, and several species depending on prairie dogs have achieved listing status under the Endangered Species Act. We propose that managing the praire dog would provide an effective avenue from single-species management to management of a system. Because prairie dogs have declined so profoundly, some form of legal protection will be required. In addition, protected areas can preserve habitat and integrate ecologically sound agricultural opportunities. Positive incentives for ranchers to manage in the interests of both livestock and wildlife will enhance the attitude change necessary for grassland conservation. These management options hinge critically on an end to U.S. government subsidies for prairie dog eradication programs. The subsidies are financially and ecologically unsound, and they only contribute to the prevailing misconceptions about the role of the prairie dog on the grasslands.     

Effects of changes in climate on landscape and regional processes, and feedbacks to the climate system

Biological and physical processes in the Arctic system operate at various temporal and spatial scales to impact large-scale feedbacks and interactions with the earth system. There are four main potential feedback mechanisms between the impacts of climate change on the Arctic and the global climate system: albedo, greenhouse gas emissions or uptake by ecosystems, greenhouse gas emissions from methane hydrates, and increased freshwater fluxes that could affect the thermohaline circulation. All these feedbacks are controlled to some extent by changes in ecosystem distribution and character and particularly by large-scale movement of vegetation zones. Indications from a few, full annual measurements of CO2 fluxes are that currently the source areas exceed sink areas in geographical distribution. The little available information on CH4 sources indicates that emissions at the landscape level are of great importance for the total greenhouse balance of the circumpolar North. Energy and water balances of Arctic landscapes are also important feedback mechanisms in a changing climate. Increasing density and spatial expansion of vegetation will cause a lowering of the albedo and more energy to be absorbed on the ground. This effect is likely to exceed the negative feedback of increased C sequestration in greater primary productivity resulting from the displacements of areas of polar desert by tundra, and areas of tundra by forest. The degradation of permafrost has complex consequences for trace gas dynamics. In areas of discontinuous permafrost, warming, will lead to a complete loss of the permafrost. Depending on local hydrological conditions this may in turn lead to a wetting or drying of the environment with subsequent implications for greenhouse gas fluxes. Overall, the complex interactions between processes contributing to feedbacks, variability over time and space in these processes, and insufficient data have generated considerable uncertainties in estimating the net effects of climate change on terrestrial feedbacks to the climate system. This uncertainty applies to magnitude, and even direction of some of the feedbacks.