Browsing by Author "Cairns, John Jr."

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    Abiotic and biotic factors influencing the decline of native unionid mussels in the Clinch River, Virginia
    Yeager, Mary Melinda (Virginia Tech, 1994)
    Declining unionid populations in the Clinch River are of concern due to the high endemism in the diverse fauna of the Cumberlandian region. Increase in agricultural and mining activities, as well as in industry and urbanization, are coupled with unionid declines throughout the watershed. In many reaches of the Clinch River, mussel populations exist which fail to show recruitment suggesting that this is the weak link in the complex life cycle. Two possible factors which could endanger the sensitive juvenile stage are the presence of sediment toxicants or adult Corbicula fluminea in the depositional areas, the preferred habitat of the juveniles. Before investigating the impacts of these factors, it was necessary to characterize the relationship of the juveniles with the sediment they inhabit. Observations of feeding behavior using videotape, dye studies in a feeding chamber, and gut content analysis were used to determine mechanisms of feeding, the primary food source, and the origin of substances taken up by juveniles. Exposure to sediment came not only through direct contact, but also through filtration of interstitial water and sediment-associated fine particulate organic matter. Juveniles used pedal locomotory and pedal sweep feeding behaviors to facilitate movement of particles into the pedal gape. Intermittent sediment toxicity was found in laboratory bioassays using Daphna magna and Chironomus riparius. These data, along with fluctuating metals in the Clinch River sediments, indicated that acute insults existed from which recovery would depend on the frequency, intensity and duration of the events. Field studies revealed that the intermittent toxicity is reflected in the community structure of benthic macroinvertebrates and impairs growth of juvenile unionids in-situ studies. The intermittent toxicity which may be associated with rain events impairs stream biota and may prevent recruitment of juvenile unionids. The presence of adult C. fluminea in sediments was found to decrease juvenile unionid growth and recovery from test sediments and to increase mortality and resuspension of juveniles into the water column. Both the presence of sediment-bound toxicants and C. fluminea may be contributing to unionid bivalve declines in the Clinch River, Virginia.
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    Adapting to Symptoms of Global Warming Rather Than Addressing the Cause
    Cairns, John Jr. (Virginia Tech, 2006)
    In recent years, global warming has been ignored and scientists producing evidence supporting this hypothesis have been denigrated and even investigated. However, as irrefutable evidence showing that global warming was a reality mounted, the message shifted to global warming may be occurring, but it is not caused by human activity. Now the message is shifting again, and humankind I been told to adapt to global warming instead of making an effort to reverse it.
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    Alteration and recovery of a stream macroinvertebrate community exposed to fly ash effluent and an analysis of the causative factors
    Specht, Winona L. (Virginia Polytechnic Institute and State University, 1985)
    Structural and functional changes in the macroinvertebrate community of a fly ash receiving stream were investigated during the final year of fly ash basin operation and for 10 months after fly ash discharges to the stream were terminated. Minimal changes were observed in the benthic community until the basin reached 77% of capacity, at which time the number of macroinvertebrate taxa, density of organisms, diversity, and relative abundance of Ephemeroptera all declined sharply. Ephemeroptera (mayflies) exhibited the greatest sensitivity to the fly ash effluent, while the beetle, Psephenus herricki (Coleoptera) was very resistant to the effects of fly ash. Recovery responses of the macroinvertebrate community were observed one month after fly ash discharges to the stream ended, while full recovery required 10 months. Based on the results of the field study, the toxicity of fly ash constituents (fly ash particulates, pH excursions, and heavy metals) was examined in three species of aquatic insects: Stenonema pudicum (Ephemeroptera), Hydropsyche slossonae (Trichoptera), and Psephenus herricki. Fly ash particulates were not acutely toxic to the three species at concentrations of 4000 mg/l. Stenonema pudicum was consistently the most sensitive species to acidic and alkaline pH extremes and heavy metals (Cd, Cr, Cu, Zn, and a metal mixture), while Psephenus herricki was consistently the most resistant species tested. Alkaline pH extremes and elevated heavy metal concentrations are believed to be responsible for the observed changes in the macroinvertebrate community of the receiving stream during the final two months of basin operation, while elevated heavy metal concentrations were responsible for earlier perturbation of the stream community.
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    An analysis of palustrine forested wetland compensation effectiveness in Virginia
    Atkinson, Robert B. (Virginia Tech, 1991-09-03)
    Plans to construct a wetland to replace wetland losses has become a common feature of permit requests. The purpose of this project is to suggest a methodology for quantifying the effectiveness of palustrine forested wetland construction in Virginia. Wetlands constructed by ~ne Virginia Department of Transportation and the U.S. Army Corps of Engineers were surveyed and Wagner Road constructed wetland in Petersburg, Virginia was selected as the primary study site. Chapter One of the present study suggests a method for early assessment of revegetation success utilizing weighted averages of colonizing vegetation. An adjacent reference site was chosen that was in close proximity to the constructed site and was used for comparison. Results from the Wagner Road site and the reference wetland indicated that colonizing vegetation weighted averages provide a more sensitive measure of revegetation success than the methods described in the federal wetland delineation manual.
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    Aquatic invertebrate recovery in the Clinch River following hazardous spills and floods
    Crossman, John S.; Cairns, John Jr.; Kaesler, Roger L. (Water Resources Research Center, Virginia Polytechnic Institute and State University, 1973)
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    Aquatic microbial community responses to stress: comparison of nontaxonomic and taxonomic indices
    Toczydlowski, David G. (Virginia Tech, 1985-05-05)
    Three nontaxonomic indices; ATP/Chlorophyll a(ATP/Chla), ATP/ADP, and Chlorophyll a/Pheopigment (Chla/Pheo) were compared to the taxonomic measures of species diversity (d) and species richness as indicators of stress in aquatic environments. Field and laboratory microcosm responses of indigenous microbial communities exposed to municipal sewage treatment plant (STP) effluent were monitored. The STP effluent produced increased adenylate concentrations, ATP/ADP and ATP/Chla ratios, and decreased Chla, Chla/Pheo, d, and species richness relative to upstream reference communities. Nontaxonomic responses were consistent in four separate field tests. Significant differences in responses were discernible in 3 d when communities were transferred from reference to polluted sites. Chla/Pheo decreased more rapidly than other measurements. The predictive capability of laboratory flow through microcosm tests was examined by simultaneously transferring communities from upstream reference sites to downstream field sites and to various dilutions of field effluent in the laboratory.
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    Are Humans too Numerous to Become Extinct?
    Cairns, John Jr. (Virginia Tech, 2009)
    Some claim that humans are too numerous to become extinct. However, passenger pigeon, once the most numerous birds on the planet, are now extinct. For years, humankind has been damaging its habitat, discharging toxic chemicals into the environment, and having harmful effects on agricultural productivity due to climate change. Humankind s extinction depends on the continuation of various human activities including economic growth, addiction to fossil fuel, over consumption, overpopulation, ocean acidification, and use of toxicants. If humankind wants to remain on this planet, it must start preparing for a vastly different environment on Earth.
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    Are We Asking the Right Questions to Guide Our Descent From the 2007 Oil Peak?
    Cairns, John Jr. (Virginia Tech, 2007)
    Peak oil may have been reached in 2007, if so; a new source of energy will be needed. Coal would be a poor substitute as it produces twice as many greenhouse gas emissions when burnt, and biofuels have huge drawbacks, as expected when food is converted to fuel. Ethics and morals should have a major impact on the policies aiding the transition from peak oil to the eventual much reduced per capita energy consumption. Decision makers must have does humankind have a _right to endanger posterity by continuing profligate use of fossil energy?
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    Assimilative Capacity Revisited
    Cairns, John Jr. (Asian Journal of Experimental Sciences, 2008)
    Assimilative capacity is the ability of natural systems to assimilate humankind's wastes. Wastes (output) of some species in natural systems are the resources (input) of other species. Before the Industrial Revolution, this concept of input and output held true for human activity, but industrialization created wastes that were qualitatively and quantitatively different from those of natural systems. The unique nature of some persistent wastes that accumulate in organisms over long periods of time makes estimates of safety problematic. An even larger problem is the devastating effects that global heating and other types of climate change are having on the integrity of ecosystems. An ecosystem in disequilibrium probably has no assimilative capacity. Since greenhouse gas emissions are increasing rapidly, the already bad situation will worsen. Another factor diminishing the probability of the effective use of the assimilative capacity concept is ecological overshoot (i.e., humankind's failing to live on ecological services and using ecological capital as a substitute), which is an unsustainable practice. Biotic impoverishment (i.e., loss of biodiversity) also increases the probability of ecological disequilibrium. Finally, exponential growth of the human population, about 1.5 million additional people weekly, means a steadily increasing loss of space for natural systems and more acquisition of natural resources for human use. In short, present waste disposal practices are no longer suitable.
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    Beyond Ecocentrism
    Cairns, John Jr. (EcoRes Forum, 2007)
    In order to avoid further damage to the ecosystems, we must promote ecological health as the primary goal, which will require at least two steps beyond ecocentrism. First, one must regard the relationship between humankind and natural systems as co-evolutionary. Second, one must develop an ecolate perspective free from _feel good social, ethical, and political rhetoric.
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    Biological and chemical monitoring of three streams in the area of Blacksburg, Virginia
    Hayles, Virginia Mosby (Virginia Tech, 1973-03-15)
    This study compares the sensitivity of biological and chemical parameters for monitoring water quality, examines several methods of analyzing diversity of the aquatic organisms and attempts to assess water quality in the three streams investigated. The Cairns-Dickson DIT diversity index was applied to two trophic levels of aquatic organisms and the results were compared to ascertain whether this diversity index is applicable to all levels of the trophic\structure or of greater use for a particular level. Two diversity indices, Cairns-Dickson DIT and Wilhm-Dorris d̅, were used to analyze the same component of the biological community and the results of these two indices were compared. A correlation test was performed among chemical and biological data and among chemical parameters.
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    The Biosphere Life Support System: A Unifying Concept for Ecotoxicologists and Ecologists
    Cairns, John Jr. (Society of Environmental Toxicology and Chemistry, 2009)
    The biospheric life support system, consisting of natural capital and the ecosystem services it provides, has maintained favorable condition for humankind. Therefore, maintaining the health and integrity of the biospheric life support system is essential for the well being of humankind. Toxicologists know that increasing the biosphere s exposure to chemical substances will elicit a deleterious response in the biospheric life support system that human kind cannot afford. Ecologists know that the loss of biodiversity can be catastrophic to the ecosystem services that sustain human kind. Both scientific must come together and collaborate in order to communicate to the public how essential the biospehric life support system is to the survival of humankind.
  • Biospheric Changes are Threat Multipliers
    Cairns, John Jr. (National Academy of Sciences, 2010)
    A threat multiplier is defined as another agent that impacts a current situation, creating an additional set of problems while also making existing problems worse. Sometimes a seemingly innocent change in the biosphere can cause major alterations and become a threat multiplier. Because the biosphere is a highly interactive system, damage to a single component, like the ocean for example, will produce a ripple effect throughout the entire system. In order for humans to eliminate threat multipliers that could potentially speed up global warming, humans must change their lifestyles and convert their waste into biospheric resources. The quest for economic growth has turned the human economy into a threat multiplier since increasing consumption of resources also leads to increasing production of waste. Economic growth has already damaged and permanently altered the biosphere; consequentially, if _business as usual continues, the biospheric changes will increase threat multipliers.
  • Biospheric Feedback Loops and Rapid Global Climate Change
    Cairns, John Jr. (National Academy of Sciences, 2010)
    A positive feedback loop makes an existing process speed up while a negative feedback loop decreases the impact of an existing process. A source emits carbon dioxide and other greenhouse gases while a sink retain and stores. However, with climate change a sink can possibly become a source. Carbon, which is a basic unit of life, is stored in various parts of the atmosphere including the ocean. However, when carbon dioxide dissolves in seawater, carbonic acid is formed, which is harmful to marine organism and the marine ecosystem. In the 21st century, scientists are concerned about the escalating the positive feedback loop of carbon dioxide. If _business as usual continues, many catastrophes predicted by scientists could occur.
  • Biospheric Health and Integrity: The Top Priority for Humankind
    Cairns, John Jr. (National Academy of Sciences, 2009)
    All life on Earth depends on the biospheric life support system to provide both natural capital, or resources, and ecosystem services. Why, then, is the human economy, a subset of the biosphere, given the highest priority by both politicians and the general public? If humans do not make the biosphere s health the top priority, the effects of global warming will change the biosphere into a vastly different, unlivable system.
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    Blood, Toil, Tears, and Sweat
    Cairns, John Jr. (Asian Journal of Experimental Sciences, 2009)
    Some people alive in 1940 may remember a portion of the famous speech given on 13 May 1940 by Sir Winston Churchill to the British public. The speech was given during the dark days of World War II for the British when all appeared to be on the verge of being lost. Still, with a firm resolve and a realistic picture of the task before them, the British people responded to Churchill s plea with resolution and prevailed. Similarly, the climate crisis of the 21st century is global; time for remedial action is short; personal sacrifices may be appalling; and success is not assured. However, the alternative to taking action is equally horrendous _ letting billions of people starve and die and virtually eliminate the prospects of a quality life for posterity. The key lines of Churchill s speech are: _I say to the House as I said to ministers who have joined this government, I have nothing to offer but blood, toil, tears, and sweat. We have before us an ordeal of the most grievous kind. We have before us many, many months of struggle and suffering (full speech at http://famousquotes.me.uk/speeches/Winston_Churchill/2.htm). Churchill asked the people to war with all their might and with all their strength _ in short, total commitment.
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    Blowing Sunshine #2: Transforming Inconvenient Truths to Convenient Truths
    Cairns, John Jr. (Virginia Tech, 2006)
    Cairns has compiled a list of opportunities for Congress and other governmental entities to _blow sunshine at the efforts of scientists justifying global warming.
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    Blowing Sunshine #3: Transforming Inconvenient Truths to Convenient Truths
    Cairns, John Jr. (Virginia Tech, 2006)
    The inconvenient truth of the matter is that an overwhelming majority of mainstream scientists accept the scientific evidence on global warming. Attempting to _blow sunshine on global warming is becoming increasingly difficult because the vast majority of scientist ignore attempts to damage their reputations and integrity and keep producing more evidence via the scientific process and publishing their work in peer-reviewed, professional journals.
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    Blowing Sunshine: Transforming Inconvenient Truths to Convenient Truths
    Cairns, John Jr. (Virginia Tech, 2006)
    Cairns, to please friends who frequently comment about the depressing subjects of his writing, attempted to create a list _blowing sunshine or highlighting the good news, if any, about global warming.
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    Can Humans Respond to a Long-term Shortage of Renewable Resources
    Cairns, John Jr. (Virginia Tech, 2011)
    If humanity wishes to continue to do business as usual, it must learn to adapt to the consequences of climate change and the decreased availability of renewable resources. Responding to rapid climate change will take the cooperation of the credentialed scientists who gather the evidence and the general public. It is in the best interest of human economy to preserve natural capital, which is essential to keeping the human economy afloat. The collapse of the biosphere threatens all component species, including humankind; consequently, nurturing the biosphere is a matter of self-interest.