Sea-level rise: Destruction of threatened and endangered species habitat in South Carolina

Concern for the environment has increased over the past century, and the US Congress has responded to this concern by passing legislation designed to protect the nation’s ecological biodiversity. This legislation, culminating with the Endangered Species Act of 1973, has been instrumental in defining methods for identifying and protecting endangered or threatened species and their habitats. Current legislation, however, assumes that the range of a protected species will stay constant over time. This assumption may no longer be valid, as the unprecedented increase in the number and concentration of greenhouse gases in the atmosphere has the potential to cause a global warming of 1.0–4.5°C and a sea-level rise (SLR) of 31–150 cm by the year 2100. Changes in climate of this magnitude are capable of causing shifts in the population structure and range of most animal species. This article examines the effects that SLR may have on the habitats of endangered and threatened species at three scales. At the regional scale 52 endangered or threatened plant and animal species were found to reside within 3 m of mean sea level in the coastal stages of the US Southeast. At the state level, the habitats of nine endangered or threatened animals that may be at risk from future SLR were identified. At the local level, a microscale analysis was conducted in the Cape Romain National Wildlife Refuge, South Carolina, USA, on the adverse effects that SLR may have on the habitats of the American alligator, brown pelican, loggerhead sea turtle, and wood stork. Prepared by the Oak Ridge National Laboratory, Environmental Sciences Division, Oak Ridge, Tennessee 37831, USA; managed by Martin Marietta Energy Systems. Inc. for the US Department of Energy under contract DE-AC05-84OR21400.     

Are watershed and lacustrine controls on planktonic N2 fixation hierarchically structured?

N2 fixation can be an important source of N to limnetic ecosystems and can influence the structure of phytoplankton communities. However, watershed-scale conditions that favor N2 fixation in lakes and reservoirs have not been well studied. We measured N2 fixation and lacustrine variables monthly over a 19-month period in Waco Reservoir, Texas, USA, and linked these data with nutrient-loading estimates from a physically based watershed model. Readily available topographic, soil, land cover, effluent discharge, and climate data were used in the Soil and Water Assessment Tool (SWAT) to derive watershed nutrient-loading estimates. Categorical and regression tree (CART) analysis revealed that lacustrine and watershed correlates of N2 fixation were hierarchically structured. Lacustrine conditions showed greater predictive capability temporally. For instance, low NO3(-) concentration (<25 microg N/L) and high water temperatures (>27 degrees C) in the reservoir were correlated with the initiation of N2 fixation seasonally. When lacustrine conditions were favorable for N2 fixation, watershed conditions appeared to influence spatial patterns of N2 fixation within the reservoir. For example, spatially explicit patterns of N2 fixation were correlated with the ratio of N:P in nutrient loadings and the N loading rate, which were driven by anthropogenic activity in the watershed and periods of low stream flow, respectively. Although N2 fixation contributed <5% of the annual N load to the reservoir, 37% of the N load was derived from atmospheric N2 fixation during summertime when stream flow in the watershed was low. This study provides evidence that watershed anthropogenic activity can exert control on planktonic N2 fixation, but that temporality is controlled by lacustrine conditions. Furthermore, this study also supports suggestions that reduced inflows may increase the propensity of N2-fixing cyanobacterial blooms in receiving waters of anthropogenically modified landscapes.     

Relationship between reproductive biology and age composition and growth in Urolophus lobatus (Batoidea: Urolophidae)

The aim of the present study was to use samples, collected by trawling throughout the year along the lower west coast of Australia, to determine the reproductive biology, size and age compositions, and growth rate of Urolophus lobatus, a member of a speciose elasmobranch family (Urolophidae) for which there was previously only a small amount of such data. U. lobatus copulates about 3 months prior to the time when females ovulate, which implies that sperm is stored in the oviducal gland of the female in the intervening period. Gestation lasts for 10 months, which is relatively long for a species that does not grow to a large size. This feature is reflected in the fact that the mean disc width at parturition (105 mm) is equivalent to as much as 44% and 52% of the asymptotic disc widths of the females and males of this species, respectively. The trends exhibited by the marginal increments on vertebral centra demonstrated that each of the translucent zones in these centra is laid down annually and that their numbers can thus be used to age this species. Maturity was attained by about 70% of females and 50% of males at the end of the 4th and 3rd years after conception, respectively, or at just over 3 and 2 years after birth, respectively. Females and males typically first reach maturity at ˜200 and ∼160 mm, respectively, and attained maximal disc widths of 277 and 237 mm, respectively. Females reached maximum ages of 15 years from conception and 14 years from birth, with the corresponding values for males being 13 and 12 years, respectively. Since such a large amount of growth occurs during gestation, von Bertalanffy growth curves were constructed using the date of conception, that is, the fertilisation date, as age 0, as is usually the case with teleosts, as well as employing the birth date as age 0, as is typically the case with elasmobranchs. The growth curves drawn through the points for the disc width-at-age of the older female and male fish gave a slightly better fit when using, as age 0, the parturition date rather than the conception date. However, the asymptotic disc widths derived for females and males using the conception date, that is, 241.3 and 202.9 mm, were each still only 7.6 mm less than those derived using the birth date. Moreover, the fit of the line drawn through the points for the disc width-at-age of fish during gestation was better using the conception date as age 0 than would be achieved by a backwards extrapolation of the growth curve using the birth date as age 0. Received: 6 January 2000 / Accepted: 17 June 2000     

Water management decision makers' evaluations of uncertainty in a decision support system: the case of WaterSim in the Decision Theater

Model-based decision support systems are increasingly used to link knowledge to action for environmental decision making. How stakeholders perceive uncertainty in models and visualisations affects their perceptions of credibility, relevance and usability of these tools. This paper presents a case study of water decision makers’ evaluations of WaterSim, a dynamic water simulation model presented in an immersive decision theatre environment. Results reveal that decision makers’ understandings of uncertainty in their evaluations of decision support systems reflect both scientific and political discourse. We conclude with recommendations for design and evaluation of decision support systems that incorporate decision makers' views.     

Trends in young driver risk and countermeasures in European countries

This paper reviews European trends regarding young drivers' accident risk and the effects of countermeasures. Young driver risk differs between countries, and has improved in the last decade, probably as a result of general improvements in road safety levels. Young male drivers' relative risk is rising, indicating that current policies are less effective for males than for females. Further research is needed to understand the causes of this development. In Europe, most countries are moving toward multiphase licensing systems, including elements like accompanied driving, protective measures, and probation periods. European evaluation studies show mixed results regarding these elements, pointing to a need for more research into the effective components.     

Air revitalization compounds: A literature survey

Chemical processes for air revitalization are attractive alternatives for some closed life support systems in the applications of space and marine explorations. A review of the literature is given for the purpose of evaluating potential candidates as air revitalizing chemicals based upon a set of criteria including toxicity in use, removal of airborne contaminants and bacteria, theoretical oxygen yields, chemical reactivity to breathing atmospheres, and commercial availability. The preliminary evaluation shows potassium and sodium Superoxides as prime candidates for further evaluation against the practical considerations of actual use. Upon closer scrutiny, potassium Superoxide is the desired chemical for air revitalization in closed life support systems according to the present technology. Kinetic reaction rates for the simple hydration of KO₂ were reported to increase for increasing pressures to 12 atm making it a promising air revitalization chemical at the hyperbaric conditions encountered in deep diving.     

Precipitator Equipment

The purpose of this section is to set forth the main elements and features of the equipment used for the collection of fly ash. Hardware and structural details of a routine nature having little or no bearing on basic performance are outside the scope of the paper.     

Adaptive management for mitigating Cryptosporidium risk in source water: A case study in an agricultural catchment in South Australia

Water-borne pathogens such as Cryptosporidium pose a significant human health risk and catchments provide the first critical pollution ‘barrier’ in mitigating risk in drinking water supply. In this paper we apply an adaptive management framework to mitigating Cryptosporidium risk in source water using a case study of the Myponga catchment in South Australia. Firstly, we evaluated the effectiveness of past water quality management programs in relation to the adoption of practices by landholders using a socio-economic survey of land use and management in the catchment. The impact of past management on the mitigation of Cryptosporidium risk in source water was also evaluated based on analysis of water quality monitoring data. Quantitative risk assessment was used in planning the next round of management in the adaptive cycle. Specifically, a pathogen budget model was used to identify the major remaining sources of Cryptosporidium in the catchment and estimate the mitigation impact of 30 alternative catchment management scenarios. Survey results show that earlier programs have resulted in the comprehensive adoption of best management practices by dairy farmers including exclusion of stock from watercourses and effluent management from 2000 to 2007. Whilst median Cryptosporidium concentrations in source water have decreased since 2004 they remain above target levels and put pressure on other barriers to mitigate risk, particularly the treatment plant. Non-dairy calves were identified as the major remaining source of Cryptosporidium in the Myponga catchment. The restriction of watercourse access of non-dairy calves could achieve a further reduction in Cryptosporidium export to the Myponga reservoir of around 90% from current levels. The adaptive management framework applied in this study was useful in guiding learning from past management, and in analysing, planning and refocussing the next round of catchment management strategies to achieve water quality targets.