Measures of energy cost and value in ecosystems

The physical output of ecological processes have different values even though they may be measured in the same physical units. Using linear input-output theory, we derive a set of weights based on direct and indirect energy requirements for ecosystem commodities which uniquely converts them into commensurable unit costs. Under certain conditions, these costs are equal to values or prices. Using this system, behavioral theories can be better posed for experimental verification.     

Polycyclic musk compounds in higher trophic level aquatic organisms and humans from the United States

Polycyclic musks, 1,3,4,6,7,8-hexahydro-4,6,6,7,8,8-hexamethylcyclopenta[g]-2-benzopyran (HHCB) and 7-acetyl-1,1,3,4,4,6-hexamethyl-1,2,3,4-tetrahydronaphthalene (AHTN), are used as fragrance ingredients in numerous consumer products such as cleaning agents and personal care products. Studies have reported the widespread occurrence of these musks in surface waters and fish from western European countries. Nevertheless, little is known about their accumulation in humans and wildlife in the United States. In this study, we measured concentrations of HHCB and AHTN in human adipose fat collected from New York City. Furthermore, tissues from marine mammals, water birds, and fish collected from US waters were analyzed to determine the concentrations of HHCB and AHTN. Concentrations of HHCB and AHTN in human adipose fat samples ranged from 12 to 798 and from <5 to 134 ng/g, on a lipid weight basis, respectively. A significant correlation existed between the concentrations of HHCB and AHTN in human adipose fat. Concentrations of HHCB and AHTN were not positively correlated with age or gender of the donors. HHCB was found in tissues of several wildlife species, but not in the livers of polar bear from the Alaskan Arctic. Among wildlife species analyzed, spinner and bottlenose dolphins collected from Florida coastal waters contained measurable concentrations of HHCB.     

Nitrogen oxides emission control options for coal-fired electric utility boilers

Recent regulations have required reductions in emissions of nitrogen oxides (NOx) from electric utility boilers. To comply with these regulatory requirements, it is increasingly important to implement state-of-the-art NOx control technologies on coal-fired utility boilers. This paper reviews NOx control options for these boilers. It discusses the established commercial primary and secondary control technologies and examines what is being done to use them more effectively. Furthermore, the paper discusses recent developments in NOx controls. The popular primary control technologies in use in the United States are low-NOx burners and overfire air. Data reflect that average NOx reductions for specific primary controls have ranged from 35% to 63% from 1995 emissions levels. The secondary NOx control technologies applied on U.S. coal-fired utility boilers include reburning, selective noncatalytic reduction (SNCR), and selective catalytic reduction (SCR). Thirty-six U.S. coal-fired utility boilers have installed SNCR, and reported NOx reductions achieved at these applications ranged from 15% to 66%. Recently, SCR has been installed at >150 U.S. coal-fired utility boilers. Data on the performance of 20 SCR systems operating in the United States with low-NOx emissions reflect that in 2003, these units achieved NOx emission rates between 0.04 and 0.07 lb/10(6) Btu.     

Elemental composition of Hoh Rainforest Olympic National Park Washington, USA

The concentration, enrichment factor and storage of 27 elements was examined for growing in Olympic National Park, Washington. Most element concentrations changed significantly as the moss aged. Concentrations of copper, zinc, and lead were among the lowest found to date. Crustal enrichment factors indicated many elements were initially derived from atmospheric sources. These data indicate concentrations of heavy metals in remote, unpolluted sites may be considerably lower than initially thought.Mosses have been used to monitor air pollution because they accumulate trace elements and their growth is sensitive to pollutants. and were used to monitor trace element contamination in Europe (Yale and Lloyd 1984, Goodman and Roberts 1971, Lotschert and Wardtner 1982). The older portions of tended to have higher concentrations of copper and zinc than the newer portions. Sweiboda and Kalemba (1981) used and other mosses to monitor the presence of sulfur and flourine. An ecological index of contamination was developed by Le Blanc, et al. (1974) based heavily on the presence and absence of lichen and moss species around a copper mill area in Quebec, Canada. These studies demonstrate that the chemical composition of moss tissues and changes in species abundance are sensitive to atmospheric chemical composition.     

Monitoring dissolved organic carbon in surface and drinking waters

The presence of natural organic matter (NOM) strongly impacts drinking water treatment, water quality, and water behavior during distribution. Dissolved organic carbon (DOC) concentrations were determined daily over a 22 month period in river water before and after conventional drinking water treatment using an on-line total organic carbon (TOC) analyzer. Quantitative and qualitative variations in organic matter were related to precipitation and runoff, seasons and operating conditions. Following a rainfall event, DOC levels could increase by 3.5 fold over baseflow concentrations, while color, UV absorbance values and turbidity increased by a factor of 8, 12 and 300, respectively. Treated water DOC levels were closely related to the source water quality, with an average organic matter removal of 42% after treatment.     

Recruitment,growth, and diel vertical migration of Euphausia pacifica in a temperate fjord

The pelagic crustacean Euphausia pacifica Hansen was sampled with a multiple-sample 1.0 m² Tucker trawl and a multiple-sample 1.0 m² vertical net in Dabob Bay, Washington on 17 dates between May 1985 and October 1987. Size (stage) structure and abundance of the population were determined for each date, while vertical distribution and diel migration were determined for 13 dates. Although internannual variability in both timing and magnitude of events occurred, consistent patterns were discernable. The population produced a large pulse of larvae (2 to 5 mm) in late spring of each year, apparently in response to the vernal phytoplankton bloom. Much lower abundances of larvae occurred during summer and autumn of each year, and larvae were completely absent during winter. Recruitment to the juvenile (6 to 9 mm) and adult (10 mm) stages was strongest during the summer, with abundances of these individuals peaking in summer and autumn. Individual growth rates, determined by modal progression analysis, were calculated for E. pacifica. Rates ranged from zero for some adult cohorts during the winter to 0.12 mm d^-1 for larvae during spring. The latter are among the highest ever reported for this species in the field. The vertical distributions and diel vertical migrations (DVM) of E. pacifica varied seasonally and between size (stage) classes. At night, all size classes were distributed in the surface layer (upper 25 m) irrespective of season or year. During the day, the larger/older stages were always distributed at middepths (50 to 125 m). In contrast, the daytime distribution of the larvae was more variable, being concentrated at the surface during spring and early summer of 1985, and at increasing depths later in the summer and autumn of 1985 and again in spring of 1986. This resulted in invariant DVM in the juveniles and adults, but variable DVM in the larvae, the latter of which is hypothesized to be a response to variable abundances of zooplanktivorous fish.     

Land Use, Spatial Scale, and Stream Systems: Lessons from an Agricultural Region

We synthesized nine studies that examined the influence of land use at different spatial scales in structuring biotic assemblages and stream channel characteristics in southeastern Minnesota streams. Recent studies have disagreed about the relative importance of catchment versus local characteristics in explaining variation in fish assemblages. Our synthesis indicates that both riparian- and catchment-scale land use explained significant variation in water quality, channel morphology, and fish distribution and density. Fish and macroinvertebrate assemblages can be positively affected by increasing the extent of perennial riparian and upland vegetation. Our synthesis is robust; more than 425 stream reaches were examined in an area that includes a portion of three ecoregions. Fishes ranged from coldwater to warmwater adapted. We suggest that efforts to rehabilitate stream system form and function over the long term should focus on increasing perennial vegetation in both riparian areas and uplands and on managing vegetation in large, contiguous blocks. Minnesota Cooperative Fish and Wildlife Research Unit is jointly sponsered by U.S. Geological Survey Biological Resources Division, the University of Minnesota, The Minnesota Department of Natural Resources, and the Wildlife Management Institute.     

Measuring Biotechnology Employees’ Ethical Attitudes towards a Controversial Transgenic Cattle Project: The Ethical Valence Matrix

What is the relationship between biotechnology employees’ beliefs about the moral outcomes of a controversial transgenic research project and their attitudes of acceptance towards the project? To answer this question, employees (n=466) of a New Zealand company, AgResearch Ltd., were surveyed regarding a project to create transgenic cattle containing a synthetic copy of the human myelin basic protein gene (hMBP). Although diversity existed amongst employees’ attitudes of acceptance, they were generally: in favor of the project, believed that it should be allowed to proceed to completion, and that it is acceptable to use transgenic cattle to produce medicines for humans. These three items were aggregated to form a project acceptance score. Scales were developed to measure respondents’ beliefs about the moral outcomes of the project for identified stakeholders in terms of the four principles of common morality (benefit, non-harm, justice, and autonomy). These data were statistically aggregated into an Ethical Valence Matrix for the project. The respondents’ project Ethical Valence Scores correlated significantly with their project acceptance scores (r=0.64, p<0.001), accounting for 41% of the variance in respondents’ acceptance attitudes. Of the four principles, non-harm had the strongest correlation with attitude to the project (r=0.59), followed by benefit and justice (both r=0.54), then autonomy (r=0.44). These results indicate that beliefs about the moral outcomes of a research project, in terms of the four principles approach, are strongly related to, and may be significant determinants of, attitudes to the research project. This suggests that, for employees of a biotechnology organization, ethical reasoning could be a central mechanism for the evaluation of the acceptability of a project. We propose that the Ethical Valence Matrix may be used as a tool to measure ethical attitudes towards controversial issues, providing a metric for comparison of perceived ethical consequences for multiple stakeholder groups and for the evaluation and comparison of the ethical consequences of competing alternative issues or projects. The tool could be used to measure both public and special interest groups’ ethical attitudes and results used for the development of socially responsible policy or by science organizations as a democratizing decision aid to selection amongst projects competing for scarce research funds.