Landscape-Based Assessment of Human Disturbance for Michigan Lakes

Assessment of lake impairment status and identification of threats’ type and source is essential for protection of intact, enhancement of modified, and restoration of impaired lakes. For regions in which large numbers of lakes occur, such assessment has usually been done for only small fractions of lakes due to resource and time limitation. This study describes a process for assessing lake impairment status and identifying which human disturbances have the greatest impact on each lake for all lakes that are 2 ha or larger in the state of Michigan using readily available, georeferenced natural and human disturbance databases. In-lake indicators of impairment are available for only a small subset of lakes in Michigan. Using statistical relationships between the in-lake indicators and landscape natural and human-induced measures from the subset lakes, we assessed the likely human impairment condition of lakes for which in-lake indicator data were unavailable using landscape natural and human disturbance measures. Approximately 92% of lakes in Michigan were identified as being least to marginally impacted and about 8% were moderately to heavily impacted by landscape human disturbances. Among lakes that were heavily impacted, more inline lakes (92%) were impacted by human disturbances than disconnected (6%) or headwater lakes (2%). More small lakes were impacted than medium to large lakes. For inline lakes, 90% of the heavily impacted lakes were less than 40 ha, 10% were between 40 and 405 ha, and 1% was greater than 405 ha. For disconnected and headwater lakes, all of the heavily impacted lakes were less than 40 ha. Among the anthropogenic disturbances that contributed the most to lake disturbance index scores, nutrient yields and farm animal density affected the highest number of lakes, agricultural land use affected a moderate number of lakes, and point-source pollution and road measures affected least number of lakes. Our process for assessing lake condition represents a significant advantage over other routinely used methods. It permits the evaluation of lake condition across large regions and yields an overall disturbance index that is a physicochemical and biological indicator weighted sum of multiple disturbance factors. The robustness of our approach can be improved with increased availability of high-resolution disturbance datasets.     

Forgivingness, Pessimism, and Environmental Citizenship

Our attitudes toward human culpability for environmental problems have moral and emotional import, influencing our basic capacities for believing cooperative action and environmental repair are even possible. In this paper, I suggest that having the virtue of forgivingness as a response to environmental harm is generally good for moral character, preserving us from morally risky varieties of pessimism and despair. I define forgivingness as a forward-looking disposition based on Robin Dillon’s conception of preservative forgiveness, a preparation to be deeply and abidingly accepting yet expecting human error. As with other virtues, however, preservative forgiveness is available to some of us more than others; in the second half of this paper, I consider the deep challenge posed by rational pessimism, especially on the part of those who have been given many reasons not to hope for the very moral improvements for which they strive. I conclude that for those of us with the power roles and personal resources especially conducive to environmental activism, preservative forgiveness inclines us to remain engaged in environmental activism with fellow flawed human beings, recognizing our own mutual depredations while committing us to cooperatively respond.     

Enrichment of fetal nucleated cells from maternal blood: Model test system using cord blood

The presence of small numbers of fetal nucleated red cells in the maternal circulation has been a stimulus for the development of technologies for non-invasive prenatal genetic analysis. Our laboratory has been assessing the feasibility of density gradient centrifugation followed by magnetic activated cell sorting (MACS) of cells expressing CD32 and CD45, to deplete maternal nucleated blood cells. We have examined the efficiency of each of the steps of this procedure using cord blood from term pregnancies as a source of nucleated red blood cells. Cord blood was shown to contain highly variable numbers of nucleated red cells. Three different density gradients were examined. There was no major difference in the performances of the double and triple gradients. Density gradient centrifugation resulted in enrichments of nucleated red blood cells of about 1000-fold relative to the total cell count. However, it was apparent that the selection of the cell layers which were most enriched for these cells would result in significant losses of nucleated red cells in other layers. MACS sorting of cells using CD45 resulted in white cell depletions ranging from 7 to 34-fold. These data provide a foundation for comparison with other methods and for optimization of the MACS technique.     

Water quality associated public health risk in Bo, Sierra Leone

Human health depends on reliable access to safe drinking water, but in many developing countries only a limited number of wells and boreholes are available. Many of these water resources are contaminated with biological or chemical pollutants. The goal of this study was to examine water access and quality in urban Bo, Sierra Leone. A health census and community mapping project in one neighborhood in Bo identified the 36 water sources used by the community. A water sample was taken from each water source and tested for a variety of microbiological and physicochemical substances. Only 38.9% of the water sources met World Health Organization (WHO) microbial safety requirements based on fecal coliform levels. Physiochemical analysis indicated that the majority (91.7%) of the water sources met the requirements set by the WHO. In combination, 25% of these water resources met safe drinking water criteria. No variables associated with wells were statistically significant predictors of contamination. This study indicated that fecal contamination is the greatest health risk associated with drinking water. There is a need to raise hygiene awareness and implement inexpensive methods to reduce fecal contamination and improve drinking water safety in Bo, Sierra Leone.     

Anti-grazing activity and seasonal variation of dimethylsulfoniopropionate-associated compounds in the invasive alga <Emphasis Type="Italic">Codium fragile</Emphasis> ssp. <Emphasis Type="Italic">tomentosoides</Emphasis>

In this study, we present evidence that the invasive alga Codium fragile ssp. tomentosoides is chemically defended against grazing by a wound-activated chemical defense involving dimethylsulfoniopropionate (DMSP) and the products of its cleavage, dimethylsulfide (DMS), and acrylic acid (AA). DMSP in C. fragile ssp. tomentosoides was present throughout the year, but concentrations varied seasonally and were highest in the winter. Intra-thallus variation was neither large, nor consistent over time. High DMSP concentrations were uncommon among northwestern Atlantic macrophytes. Of 26 other species tested, only two, Ulva lactuca and Polysiphonia harveyi contained concentrations comparable to, or higher than, those of C. fragile ssp. tomentosoides. DMS and AA, both individually and together, deterred grazing by the green sea urchin Strongylocentrotus droebachiensis at “natural” concentrations. These results suggest that DMS and AA contribute to the avoidance of C. fragile ssp. tomentosoides by S. droebachiensis. As a result, the production of DMSP and its subsequent cleavage, upon injury, may reduce herbivory on C. fragile ssp. tomentosoides and contribute to its success.     

Agricultural legacies in forest environments: tree communities, soil properties, and light availability.

Temperate deciduous forests across much of Europe and eastern North America reflect legacies of past land use, particularly in the diversity and composition of plant communities. Intense disturbances, such as clearing forests for agriculture, may cause persistent environmental changes that continue to shape vegetation patterns as landscapes recover. We assessed the long-term consequences of agriculture for environmental conditions in central New York forests, including tree community structure and composition, soil physical and chemical properties, and light availability. To isolate the effects of agriculture, we compared 20 adjacent pairs of forests that were never cleared for agriculture (primary forests) and forests that established 85-100 years ago on plowed fields (secondary forests). Tree communities in primary and secondary forests had similar stem density, though secondary forests had 14% greater basal area. Species composition differed dramatically between the two forest types, with primary forests dominated by Acer saccharum and Fagus grandifolia and secondary forests by Acer rubrum and Pinus strobus. Primary and secondary forests showed no consistent differences in soil physical properties or in the principal gradient of soil fertility associated with soil pH. Within stands, however, soil water content and pH were more variable in primary forests. Secondary forest soils had 15% less organic matter, 16% less total carbon, and 29% less extractable phosphorus in the top 10 cm than adjacent primary stands, though the ranges of the forest types mostly overlapped. Understory light availability in primary and secondary forests was similar. These results suggest that, within 100 years, post-agricultural stands have recovered conditions comparable to less disturbed forests in many attributes, including tree size and number, soil physical properties, soil chemical properties associated with pH, and understory light availability. The principal legacies of agriculture that remain in these forests are the reduced levels of soil organic matter, carbon, and phosphorus; the spatial homogenization of soil properties; and the altered species composition of the vegetation.     

The development of point-of-use water filters as sampling devices in bioforensics: extent of microbial sorption and elution

The foundational idea for this project is that household faucet-mounted water filters may be used as bioforensic sampling devices to detect the extent of a potential bioagent release in domestic water supplies. An optimized eluent solution was determined experimentally by quantifying recoveries of microorganisms from point-of-use (POU) drinking water filters. The optimized extraction protocol was then used in mock bioagent release experiments to determine the feasibility of POU filters as bioforensic sampling devices. Bacillus atrophaeus spores, Escherichia coli and PP7 virus were exposed to filters and the number of attached organisms was determined by enumerating the unattached organisms on selective agar media. Subsequently, the filters were eluted and the percent of extracted organisms was determined based on the number of attached organisms. Two popular brands of carbon block filters retained 92%-99% of representative virus, spore and vegetative bacteria. In back-flush elutions of single filters, the most efficient eluent was identified as a combination of 1% peptone and 1% Tween-80, and extraction recovered 25.4% (+/-17.5%) of attached E. coli, 20.4% (+/-3.6%) of B. atrophaeus spores, and 9.4% (+/-5.2%) of PP7 virions (+/- standard deviations). In bioagent release studies in which filters were challenged with 100 agents mL(-1), greater than 99% of the spores were retained by the filters, and the percent of attached spores that were recovered ranged from 10.4% at day 0 to 4.3% five days after the release event (averaged from five separate experiments). In contrast, E. coli, Salmonella typhimurium and PP7 virus were rapidly inactivated in the chlorinated tap water, indicating their improbable survival in chlorinated water supplies. It is therefore concluded that household water filters can be used as microbial sampling devices for bioforensic applications in the event of a bioagent release in domestic drinking water supplies.     

Developing Life‐Cycle Environmental Response Costs for Leaking Underground Storage Systems at Service Station Sites

Leaking underground storage tank systems at service stations have resulted in tens of thousands of petroleum releases and associated groundwater chemical plumes often extending hundreds of feet off‐site. Technical and engineering approaches to assess and clean up releases from underground tanks, product lines, and dispensers using technologies such as soil vapor extraction, air sparging, biostimulation, and monitored natural attenuation are well understood and widely published throughout the literature. This article summarizes life‐cycle environmental response costs typically encountered using site‐specific cost estimation or metric‐based cost categories considering the overall complexity of site conditions: (1) simple sites where response actions require smaller scale assessments and/or remediation and have limited or no off‐site impacts; (2) average sites where response actions require larger scale assessments and/or remediation typical of petroleum releases; (3) complex sites where response actions require greater on‐site and/or off‐site remediation efforts; and (4) mega sites where petroleum plumes have impacted public or private water supplies or where petroleum vapors have migrated into occupied buildings. Associated cleanup cost estimates rely upon appropriate combinations of individual work elements and the duration of operation, maintenance, and monitoring activities. These cost estimates can be offset by state reimbursement funds, coverage in purchase agreements, and insurance policies. A case study involving a large service station site portfolio illustrates the range of site complexity and life‐cycle environmental response costs. © 2014 Wiley Periodicals, Inc.