USE OF STAGE DATA TO CHARACTERIZE HYDROLOGIC CONDITIONS IN AN URBANIZING ENVIRONMENT1

ABSTRACT: This paper presents the results of a study on the use of continuous stage data to describe the relation between urban development and three aspects of hydrologic condition that are thought to influence stream ecosystems—overall stage variability, stream flashiness, and the duration of extreme‐stage conditions. This relation is examined using data from more than 70 watersheds in three contrasting environmental settings—the humid Northeast (the metropolitan Boston, Massachusetts, area); the very humid Southeast (the metropolitan Birmingham, Alabama, area); and the semiarid West (the metropolitan Salt Lake City, Utah, area). Results from the Birmingham and Boston studies provide evidence linking increased urbanization with stream flashiness. Fragmentation of developed land cover patches appears to ameliorate the effects of urbanization on overall variability and flashiness. There was less success in relating urbanization and streamflow conditions in the Salt Lake City study. A related investigation of six North Carolina sites with long term discharge and stage data indicated that hydrologic condition metrics developed using continuous stage data are comparable to flow based metrics, particularly for stream flashiness measures.     

Convergence of Culture, Ecology, and Ethics: Management of Feral Swamp Buffalo in Northern Australia

This paper examines the identity of Asian swamp buffalo (Bubalus bubalis) from different value orientations. Buffalo were introduced into Northern (Top End) Australia in the early nineteenth century. A team of transdisciplinary researchers, including an ethicist, has been engaged in field research on feral buffalo in Arnhem Land over the past three years. Using historical documents, literature review, field observations, interviews with key informants, and interaction with the Indigenous land owners, an understanding of the diverse views on the scientific, cultural, and economic significance of buffalo was obtained. While the diverse stakeholders in buffalo exploitation and management have historically delivered divergent value orientations on the nature of the human–buffalo relationship, we argue that over time there is the possibility of values and ethical convergence. Such convergence is possible via transdisciplinary and transcultural agreement on the value stances that constitute the construction of the being or identity of buffalo in the face of the overwhelming need to manage population density and gross numbers.     

Components of the Total Water Balance of an Urban Catchment

A daily model was used to quantify the components of the total urban water balance of the Curtin catchment, Canberra, Australia. For this catchment, the mean annual rainfall was found to be three times greater than imported potable water, and the sum of the output from the separate stormwater and wastewater systems exceeded the input of imported potable water by some 50%. Seasonal and annual variations in climate exert a very strong influence over the relative magnitude of the water balance components; this needs to be accounted for when assessing the potential for utilizing stormwater and wastewater within an urban catchment.     

Attitudes and Perceptions about Ecological Resources and Hazards of People Living Aroung the Savannah River Site

Although considerable attention is devoted to environmental monitoring and assessment with respect to both pollutants and the status of particular plant or animal populations, less attention is devoted to assessing people's attitudes about the relative importance of ecological resources. In this paper we examine the attitudes and perceptions about ecological resources of people living around the Department of Energy's Savannah River Site (SRS), in South Carolina. Our overall hypothesis is that people who are directly affected by the possible outcomes and consequences of a particular hazard (i.e., those people employed at SRS) will undervalue the risks and overvalue the potential benefits from future land uses that favor continued site activity, compared to people who live near but are not employed at SRS. We interviewed 286 people attending the Aiken Trials horse show on 14 March 1997. There were few gender differences, although men hunted and fished more than women, women ranked three environmental concerns as more severe than did men, and women were more concerned about the effect of SRS on property values. Maintenance of SRS as a National Environmental Research Park ranked first as a future land use; nuclear production ranked second, followed by hunting and hiking. Only residential development ranked very low as a future land use. There were many differences as a function of employment history at SRS: 1) people who work at SRS think that the federal government should spend funds to clean up all nuclear facilities, and they think less money should be spent on other environmental problems than did non-employees, 2) people who work at SRS ranked continued current uses of SRS higher than did people who never worked at SRS, and 3) people who work at SRS are less concerned about the storage of nuclear material or accidents at the site than are people who never worked at the site.     

Handling intensity and the short- and long-term survival of elephant seals: addressing and quantifying research effects on wild animals

This study addresses the consequences of repeated human handling on the survival of an endangered phocid, the southern elephant seal and the implications for wildlife research. Southern elephant seal pups were repeatedly handled during the first six weeks of their lives. The possibility that such anthropogenic research may have altered the very parameters that were being investigated is a topical and relevant study area that we address here. Our results show that there were no measurable effects on pups that were repeatedly handled and subjected to invasive research methods with respect to survivorship in the short term (the 24-day nursing period) nor in the long term (the first year of life and beyond) and hence fitness one year after handling. In support of this conclusion we were unable to detect any significant differences in the survival rates of the most intensively handled seals and the least intensively handled seals.     

Temperature acclimation of upper and lower thermal limits and freeze resistance in the nonindigenous brown mussel, Perna perna (L.), from the Gulf of Mexico

Acute and chronic upper and lower thermal limits and freeze resistance were investigated in the nonindigenous brown mussel, Perna perna, from the Texas Gulf of Mexico coast in order to assess its potential distribution in North American coastal waters. This species' long-term, incipient lower and upper thermal limits were 7.5°C and 30°C, congruent with the seasonal ambient water temperature range of 10-30°C reported for other populations worldwide. Effects of temperature acclimation and individual size on survival time were most pronounced on chronic exposures to lethal temperatures approaching incipient lower or upper thermal limits. When exposed to temperature increasing at 0.1°C min^-1, the acute upper lethal limit was 44°C regardless of acclimation temperature or individual size. P. perna had a limited freeze resistance, being intolerant of emersion at -2.5°C. This species' narrow incipient thermal limits, limited capacity for temperature acclimation and poor freeze resistance may account for its restriction to subtidal and lower eulittoral zones of cooler subtropical rocky shores. Near extinction of P. perna from Texas Gulf of Mexico waters occurred in the summer of 1997 when mean surface-water temperatures approached its incipient upper limit of 30°C.     

Attraction of the tropical bont tick,Amblyomma variegatum,to human breath and to the breath components acetone,NO and CO2

Ticks are of medical and veterinary importance and employ several cues in search of a host. Olfaction is one modality by which ticks locate a blood-meal and breath is the major vent of gaseous and volatile metabolites from the host that could contribute to this search. We studied the responses of a hunter tick, Amblyomma variegatum, to diluted human breath and five of its components (acetone, CO₂, NO, isoprene and NH₃) while walking in an air stream on a locomotion compensator. Diluted breath elicited the greatest responses of all treatments in terms of time to onset of upwind walk, attraction, speed and local search behaviour after stimulus off. Acetone, NO and CO₂ also attracted, but with a reduced speed in the case of acetone and NO. Neither isoprene nor NH₃ induced any response. Our study indicates that breath was the most adequate stimulus tested. It also attracted two other ixodid tick species, Rhipicephalus sanguineus and Ixodes ricinus, as well as the argasid tick, Ornithodorus moubata. It appears that the evolution of resource tracking in ticks included sensory and behavioural adaptations for recognition and orientation to host metabolites that are regularly expelled in breath.     

Metals in feathers of sooty tern, white tern, gray-backed tern, and brown noddy from islands in the North Pacific

Levels of heavy metals are usuallyhigher in adult than young birds because they eatlarger, more contaminated prey, or because they havehad longer to accumulate metals in their tissues.Further, levels of contaminants are usually less inbirds nesting on remote, offshore islands than inbirds breeding closer to mainland areas that areurbanized and industrialized. We examined the featherlevels of arsenic, cadmium, chromium, lead, manganese,mercury, and selenium in adult sooty terns (Sterna fuscata), gray-backed terns (Sterna lunata), and brown noddy (Anous stolidus, and adult and young white terns (Gygis alba, fromMidway Atoll, and in adult and young sooty terns andadult brown noddy from Manana Island, Hawaii (chicksof other terns were not available). We tested andrejected the null hypotheses that metal levels are notsignificantly different among species, ages, andlocations. Despite their small size, adult white ternshad the highest levels of lead, arsenic and tin. Brownnoddies had the highest levels of cadmium, chromium,manganese, and selenium. Sooty and white terns had thehighest levels of mercury. Sooty tern adults hadsignificantly higher levels of cadmium, mercury, andselenium than young, while young had significantlyhigher levels of arsenic and manganese. White ternadults had significantly higher levels of selenium andtin than young, while young had higher levels ofcadmium and mercury than adults. Except for mercury,there were significant inter-location differenceswithin species in all heavy metals. Contrary toexpectation, where the differences were great, metalsgenerally were higher in the feathers of terns andnoddies from Midway than from Manana.     

Introducing urine-enriched biochar-based fertilizer for vegetable production: acceptability and results from rural Bangladesh

Improved agricultural practices that increase yields and preserve soils are critical to addressing food insecurity and undernutrition among smallholder farmer families. Urine-enriched biochar has been shown to be an accessible and effective fertilization option in various subtropical countries; however, it is new to Bangladesh. To better understand attitudes and experiences preparing and using urine-enriched biochar fertilizer, mixed-methods research was undertaken among smallholder farmers in northeastern Bangladesh in 2016/2017. In-depth interviews were conducted with 25 respondents who had compared the production of crops grown with biochar-based fertilizer to usual practice. In addition, in areas where trainings on biochar-based fertilization had been offered, 845 farmers were asked about their experience through a quantitative survey. Interview results indicated that cow urine-enriched biochar was favored over human urine because cow urine was perceived as clean and socially acceptable, whereas human urine was considered impure and disgusting. Respondents praised biochar-based fertilizer because it increased yields, cost little, was convenient to prepare with readily available natural materials, produced tastier crops, and allowed families to share their larger yields which in turn enhanced social and financial capital. Comparative field trials indicated a 60% yield benefit in both cabbage and kohlrabi crops. Challenges included uneven access to ingredients, with some respondents having difficulty procuring cow urine and biomass feedstock. The low social, health, and financial risk of adoption and the perceived benefits motivated farmers to produce and apply biochar-based fertilizer in their gardens, demonstrating strong potential for scale-up of this technology in Bangladesh.