Data requirements of GREAT-ER: Modelling and validation using LAS in four UK catchments

Higher-tier environmental risk assessments on “down-the-drain” chemicals in river networks can be conducted using models such as GREAT-ER (Geography-referenced Regional Exposure Assessment Tool for European Rivers). It is important these models are evaluated and their sensitivities to input variables understood. This study had two primary objectives: evaluate GREAT-ER model performance, comparing simulated modelled predictions for LAS (linear alkylbenzene sulphonate) with measured concentrations, for four rivers in the UK, and investigate model sensitivity to input variables. We demonstrate that the GREAT-ER model is very sensitive to variability in river discharges. However it is insensitive to the form of distributions used to describe chemical usage and removal rate in sewage treatment plants (STPs). It is concluded that more effort should be directed towards improving empirical estimates of effluent load and reducing uncertainty associated with usage and removal rates in STPs. Simulations could be improved by incorporating the effect of river depth on dissipation rates.     

Lessons from an Evaluation of a Boater Outreach Program for Manatee Protection

Watercraft collisions account for 25–30% of manatee deaths annually in Florida. Education and outreach interventions for boaters are strategies for reducing manatee mortality. We evaluated the effectiveness of the Manatee Watch program by surveying primary boat users whose boats were approached by Manatee Watch. We compared the attitudes, knowledge, and behavioral intentions of boaters who received Manatee Watch materials with a control group of boaters observed by the Florida Marine Research Institute in Tampa Bay during 1999–2001. Results of the 51-item telephone survey with 499 boaters indicated that the Manatee Watch intervention had little effect on boater’s attitudes, knowledge, and behaviors regarding manatees. However, individual attitude scores were positively correlated with safe boating behaviors in shallow waters including maintaining a slower speed and watching out for manatees. Overall knowledge about manatees was correlated with one manatee-safe boating behavior. To improve efficacy, educators should (a) incorporate evaluation into the planning stages of program development; (b) target messages to influence boaters’ attitudes toward manatees and ecosystem health, and their feelings of ownership and empowerment; (c) facilitate active participation of the boaters; and (d) increase the duration and variety of intervention.     

Moist olive husks addition to a silty clay soil: influence on microbial and biochemical parameters

To investigate the effects of moist olive husks (MOH-residues) on soil respiration, microbial biomass, and enzymatic (o-diphenoloxidase, beta-glucosidase, dehydrogenase and alkaline phosphatase) activities, a silty clay soil was incubated with 0 (control), 8 x 10(3) (D), 16 x 10(3) (2D) and 80 x 10(3) (10D) kg ha-1 of MOH-residues on a dry weight basis. Soil respiration and microbial biomass data indicated that the addition of MOH-residues strongly increased microbial activity proportionally to the amounts added. Data of qCO2 suggested that the respiration to biomass ratio of the microbial population was strongly modified by MOH-residues additions during the first 90 days of incubation. The qCO2 data suggested a low efficiency in energy yields from C oxidation during the first 2 months of soil incubation. qFDA seemed to be relatively unaffected for treatments D and 2D as compared to the control, but was significantly lowered by the application of 10D, showing the lowest hydrolytic activity of microbial biomass in this treatment up to 360 days of incubation. o-Diphenoloxidase activity was delayed, and this delay was extended with the addition of larger quantities of MOH-residues. Alkaline phosphatase, beta-glucosidase and dehydrogenase activities were in line with the findings on microbial biomass changes and activities. The biological and biochemical data suggest that the addition of a large quantity of MOH-residues (80 x 10(3) kg ha-1) strongly modifies the soil characteristics affecting the r- and K-strategist populations, and that these changes last for at least the 360 days of incubation. The data also suggest that application rates exceeding 16 x 10(3) kg ha-1 are not recommended until the agro-chemical and -physical functions of the soil are further studied.     

Short-term variations in the pigment composition of a spring phytoplankton bloom from an enclosed experimental ecosystem

Phytoplankton samples taken during the spring bloom in the experimental enclosed ecosystem bags at Loch Ewe, Scotland, during 1983 were analysed for carotenoids and chlorophyll compounds using high-performance liquidchromatography (HPLC). Changes in the relative proportions of these pigments were related to day-to-day changes in the composition of the bloom and the physiological state of the algae. There is clear evidence for a change in the chlorophyllide a:chlorophyll a ratio, which reached a maximum as nutrient limitation occurred. No major qualitative changes in the carotenoid components were seen during the bloom; the relative proportion, however, of some carotenoids does provide useful information on the relative abundance of certain algal type in the phytoplankton.     

NEMS and MARKAL-MACRO Models for Energy-Environmental-Economic Analysis: A Comparison of the Electricity and Carbon Reduction Projections

The Annual Energy Outlook forecasts published by the United States Energy Information Administration (EIA) of the Department of Energy are based on results from the National Energy Modeling system (NEMS). This paper compares NEMS, which is used only in the U.S., with the U.S. version of MARKAL-MACRO (USMM) model, which is used in more than thirty-five countries. The two models predict similar results for the base 1999 US Annual Energy Outlook (AEO), but their results with carbon constraints are quite different. The differences of the models and those of their predictions are explained. USMM can be used to provide an alternative and complementary approach to projections of renewable technologies penetration and their potential in reducing carbon dioxide emissions in the USA.     

EPA and business: Who is the customer,who is the supplier?

By focusing on regulated businesses as “customers,” the EPA is bringing a new way of thinking to the negotiating table that is producing creative, workable solutions. The author, who was instrumental in initiating the adoption of TQM in the Environmental Protection Agency, discusses how it can be used in negotiation to resolve impasses between EPA and business and meet the needs of both.     

Heavy Metals in Terrestrial Macroinvertebrates: Species Differences Within and Between Trophic Levels

Whole animal concentrations of Pb, Zn and Cd were measured in herbivorous (1 snail species; 1 dipteran larva species), herbivorous + detritivorous (2 slug species), detritivorous (3 woodlouse species; 3 earthworm species), and carnivorous (1 carabid beetle species; 1 lithobiid centipede species) terrestrial macroinvertebrates collected at a disused Pb/Zn mine site. No evidence was found for an accretion of any metal during transference from herbivores to carnivores; the highest metal concentrations were, in fact, generally found in detritivores. The lack of metal bio-amplification during food chain transference is probably due to the sequestration of metals (notably Pb and Zn) in insoluble inorganic-rich granules within certain target organs and cells.

Earthworms and woodlice, respectively, showed major differences in metal concentrations. These differences between closely related species frequently exceeded differences between unrelated species occupying different trophic levels, and may be attributable to a combination of ill-defined ecological and physiological differences that ensure habitat and resource partitioning.     

Scent-rubbing and status signalling by male mammals

Summary There is no consensus about the function of scent-rubbing, a widespread behaviour in which mammals rub their bodies vigorously in substances, many strong-smelling and some artificial, such as rotting meat, intestinal contents and engine oil. Here we suggest that scent-rubbing is involved in status advertisement and that, as in assessment using scent marks, the mechanism used by competitors to assess potential opponents may be scent-matching. In scent-matching a resource holder is assessed (identified) by comparing its odour with odours on or near the defended resource. In scent marking the odour originates from the resource holder (glandular secretion, urine and faeces); in scent-rubbing the odour originates in the environment.A prerequisite of unambiguous scent-matching is that the odour of scent-marks should be uniquely characteristic of one individual. This may be why marking substances are very complex chemically. Scent-rubbing often occurs with scent-marking and, rather than acting independently of scent-marking, the odours acquired may either (i) add to the complexity of the signal, thus reducing signal ambiguity, or (ii) increase the range of the signal by adding a strong smelling component.Subordinates could potentially cheat by rubbing in the same odours as the resource holder. Resource holders could prevent cheating (i) by checking other status cues and by testing competitors whose scent matches, then escalating contests when the competitor's fighting ability (more formally, Resource Holding Power) proves to be lower than that of a resource holder and (ii) by mixing the substances used for scent-rubbing with the unique substances used in scent-marking.     

Composting duck excreta enriched wood shavings: C and N transformations and bacterial pathogen reductions

Composting of agricultural and domestic wastes is used increasingly to reduce weight, volume, and odor; destroy animal and plant pathogens; and improve the quality of end-products to be used as soil amendments and growth substrates. The objective of this study was to investigate the transformation of C and N and the survival of bacterial populations and pathogenic bacteria during in-vessel composting of duck excreta enriched wood shavings. Two feedstocks, collected on different dates, were composted (C1 and C2) in an enclosed hall system equipped with an electromechanical turner. Temperature was continuously recorded, whereas moisture content and bacterial counts were determined twice a week. Data showed that, although the N content of C2 was only half of that of C1, both materials were fully biostabilized at the end of the composting period as indicated by extractable lipid ratios. In the compost with the low C/N ratio (C1), all bacterial populations were eliminated, whereas fecal streptococci, total coliforms, and gram-negative bacteria were still present in C2 at the end of the composting period. Our results emphasize that the composting of manures and other organic wastes needs to be properly managed to stabilize C and N and to eliminate or reduce bacterial populations.     

Effects of forest management on soil carbon: results of some long-term resampling studies

The effects of harvest intensity (sawlog, SAW; whole tree, WTH; and complete tree, CTH) on biomass and soil C were studied in four forested sites in the southeastern US (mixed deciduous forests at Oak Ridge, TN and Coweeta, NC; Pinus taeda at Clemson, SC: and P. eliottii at Bradford, FL). In general, harvesting had no lasting effects on soil C. However, intensive temporal sampling at the NC and SC sites revealed short-term changes in soil C during the first few years after harvesting, and large, long-term increases in soil C were noted at the TN site in all treatments. Thus, changes in soil C were found even though lasting effects of harvest treatment were not. There were substantial differences in growth and biomass C responses to harvest treatments among sites. At the TN site, there were no differences in biomass at 15 years after harvest. At the SC site, greater biomass was found in the SAW than in the WTH treatment 16 years after harvest, and this effect is attributed to be due to both the N left on site in foliar residues and to the enhancement of soil physical and chemical properties by residues. At the FL site, greater biomass was found in the CTH than in the WTH treatment 15 years after harvest, and this effect is attributed to be due to differences in understory competition. Biomass data were not reported for NC. The effects of harvest treatment on ecosystem C are expected to magnify over time at the SC and FL sites as live biomass increases, whereas the current differences in ecosystem C at the TN site (which are due to the presence of undecomposed residues) are expected to lessen with time.