GEMI: Business helping business in the twenty‐first century

The Global Environmental Management Initiative (GEMI), one of the world's leaders in business‐oriented EH&S innovation, reflects on its first decade and scopes out goals for the new millennium. © 2000 John Wiley & Sons, Inc.     

Repeatability,Sensitivity, and Uncertainty Analyses of the BANCS Model Developed to Predict Annual Streambank Erosion Rates

Accelerated streambank erosion caused by channel instability can be the leading cause of sediment impairment of streams. Obtaining accurate streambank erosion rates for sediment budgeting and prioritizing mitigation efforts can be difficult and costly. One approach to quantifying streambank erosion rates is through the development and implementation of an empirically derived “Bank Assessment for Non‐point Source Consequences of Sediment” (BANCS) model. This study aims to improve the BANCS model application by evaluating repeatability between users and identifying sensitive and/or uncertain model inputs. Statistical analysis of streambank evaluations conducted by 10 different individuals suggests the implementation of the BANCS model may not be repeatable. This finding may be due to sensitive model inputs, such as streambank height and near‐bank stress level prediction method selection, and/or uncertain model inputs, such as bank material identification and the associated adjustment of erosion potential. Furthermore, it was found assessing streambanks as a group by obtaining a measure of central tendency from individual evaluations, as well as obtaining a higher level of training, may improve model implementation precision. Application of these suggestions may result in improved prediction of streambank erosion rates utilizing the BANCS model methodology.     

Estimates of critical acid loads and exceedances for forest soils across the conterminous United States

Concern regarding the impacts of continued nitrogen and sulfur deposition on ecosystem health has prompted the development of critical acid load assessments for forest soils. A critical acid load is a quantitative estimate of exposure to one or more pollutants at or above which harmful acidification-related effects on sensitive elements of the environment occur. A pollutant load in excess of a critical acid load is termed exceedance. This study combined a simple mass balance equation with national-scale databases to estimate critical acid load and exceedance for forest soils at a 1-km(2) spatial resolution across the conterminous US. This study estimated that about 15% of US forest soils are in exceedance of their critical acid load by more than 250eqha(-1)yr(-1), including much of New England and West Virginia. Very few areas of exceedance were predicted in the western US.     

Petroleum hydrocarbons in the marine bivalve Venus verrucosa: accumulation and cellular responses

Cellular and subcellular responses of the marine burrowing bivalve Venus verrucosa collected from the north-eastern coastline of Malta from January to June 1985, after exposure to petroleum hydrocarbons (PHC) were investigated. After long-term exposure to 100 gl^-1 of water-accomodated fractions (WAF) of crude oil, PHC were found to accumulate most rapidly in the digestive gland and then in the gills, with saturation levels being reached within 100 d of exposure in both cases. PHC accumulation, both in the mantle and muscle tissues, was more gradual and consistent throughout the whole exposure period. After 150 d of exposure, the digestive cells of the digestive gland were significantly reduced in height (atrophy) and exhibited reduced lysosomal membrane stability. After 144 h of exposure to higher concentration of PHC (820 and 420 gl^-1), several cytological effects were recorded, including an increase in cell volume and activity of gill mucocytes as well as in the number of haemocytes in gill blood sinuses. There was also evidence of damage to the epithelial lining of the foot, stomach and style sac and marked atrophy of the digestive cells of the digestive gland. The significance of such responses is discussed.     

Tissue distribution and excretion of 99mTc-disofenin in three marine species: Pleuronectes americanus (winter flounder), Homarus americanus (lobster), and Mya arenaria (soft-shell clam)

To determine the pharmacokinetics of a small lipophilic molecule in vivo, the distribution and accumulation of ^99mTc-radiolabelled disofenin (diisopropylacetanilide iminodiacetic acid) were traced during 1991–1992 by scintigraphy and gamma well counting in winter flounder (Pleuronectes americanus collected from Boston Harbor and Long Island Sound in 1992), lobsters (Homarus americanus collected from Massachusetts Bay in 1991), and soft-shell clams (Mya arenaria purchased in 1991). The agent was distributed throughout the bodies of lobsters within 12 s, throughout flounder within 40 s, and throughout clams within 2 min. It was concentrated most strongly by the liver of flounder, which contained 61.2±7.8% of the injected dose within 1 h of injection, and by the lobster hepatopancreas. Accumulation also occurred in the flounder kidney, lobster antennal glands, and the kidney and pericardial glands of clams. The compound was rapidly excreted from the flounder liver into the gall bladder, and from the lobster hepatopancreas into the stomach. The data suggest its excretion from the lobster antennal glands and clam kidneys. The rate of clearance of disofenin from the body varied among species: 99±2.1% of the initial dose remained in flounder sampled 16 to 24 h after injection, compared to 80.5±7% remaining in the lobster after 15 h, and 87.4±5.9% remaining in clams after 27 h. The clearance rates in flounder and lobster are considered to be minimum values because of the lack of gut activity in unfed individuals. Overall, these in vivo tracer studies establish the utility of scintigraphy for assessing the uptake and excretion of a lipid soluble compound in different taxa, and may be applicable for evaluating disease and/or environmental effects on organ function in marine animals.     

Lake eutrophication at the urban fringe,Seattle region,USA

Nutrient pollution and associated eutrophication of freshwaters threaten the ecological integrity and the services provided to humans by lakes. We examined how human residential development influenced the level of lake eutrophication in the Seattle, WA, USA, region. We surveyed 30 lakes and measured 3 indicators of eutrophication: concentrations of chlorophyll-a and phosphorus, and the proportion of algae that are inedible to zooplankton. We classified lakes based on the waste-treatment method for shoreline homes: septic, sewer, and undeveloped lakes. Septic lakes occurred along the urban-rural fringe while sewer lakes occurred near urban centers. Septic lakes were more eutrophic than sewer lakes and undeveloped lakes, as indicated by higher levels of phosphorus and chlorophyll-a. These results suggest that septic systems contribute to the high levels of eutrophication in lakes at the urban-rural fringe. Lakes at the urban-rural fringe represent an opportunity for proactive management of urban expansion to minimize lake eutrophication.     

Responses to ozone of insects feeding on a crop and a weed species

The influence of ozone on insect herbivore growth and population development was investigated. Fumigation of both pea (Pisum sativum L.) and dock (Rumex obtusifolius L.) at a range of O(3) concentrations between 21-206 nl litre(-1) produced changes in mean relative growth rates of the aphids Acyrthosiphon pisum Harris and Aphis rumicis L. of between 24 and -6% relative to controls. However, there was no evidence of a dose-related response to O(3) fumigation and no clear differences in aphid response when fumigated with the plant on prefumigated or previously unfumigated plant material. It is suggested that this may, in part, be due to the presence of NO contamination during O(3) fumigation. However, the MRGR of dock aphids was found to be greater on new compared to old leaves as well as the increase on the new growth and decrease on the old growth of fumigated plants relative to unfumigated controls. The size of egg batches of the chrysomelid beetle Gastrophysa viridula Degeer were found to be larger, survival and productivity of larvae was higher, and the food consumption lower on R. obtusifolius fumigated with 70 nl litre(-1) O(3) compared with unfumigated controls. This meant that these beetle larvae consumed less leaf area per mg of production on fumigated leaves probably because of their better nutritional quality and/or reduced leaf defences. However, the rate of development of larvae was similar on fumigated and control plants.     

Greenhouse gas emissions from Canadian peat extraction, 1990-2000: a life-cycle analysis

This study uses life-cycle analysis to examine the net greenhouse gas (GHG) emissions from the Canadian peat industry for the period 1990-2000. GHG exchange is estimated for land-use change, peat extraction and processing, transport to market, and the in situ decomposition of extracted peat. The estimates, based on an additive GHG accounting model, show that the peat extraction life cycle emitted 0.54 x 10(6) t of GHG in 1990, increasing to 0.89 x 10(6) t in 2000 (expressed as CO2 equivalents using a 100-y time horizon). Peat decomposition associated with end use was the largest source of GHGs, comprising 71% of total emissions during this 11-y period. Land use change resulted in a switch of the peatlands from a GHG sink to a source and contributed an additional 15%. Peat transportation was responsible for 10% of total GHG emissions, and extraction and processing contributed 4%. It would take approximately 2000 y to restore the carbon pool to its original size if peatland restoration is successful and the cutover peatland once again becomes a net carbon sink.     

Herbicide effects on typha latifolia (Linneaus) germination and root and shoot development

Aqueous 7-d germination and growth experiments were performed to compare responses of T. latifolia to exposures of atrazine (2-chloro-4-ethylamino-6-isopropylamine-s-atrazine) and paraquat dichloride (1,1′-dimethyl-4,4′-bipyridinium dichloride). T. latifolia seed germination was < 50 % in concentrations ≥ 1.0 mg/L of paraquat dichloride. No observed effect concentration (NOEC) and lowest observed effect concentration (LOEC) for paraquat and root growth were 0.001 and 0.01 mg/L, respectively, while NOEC and LOEC for paraquat and shoot growth were 0.01 and 0.1 mg/L, respectively following 7-d exposures. Greater than 72 % of seeds germinated in each concentration up to 30 mg/L atrazine. After 7-d exposure, NOEC and LOEC for atrazine and root growth were 0.1 and 1.0 mg/L, while atrazine and shoot growth NOEC and LOEC values were 15 and 30 mg/L, respectively. This research provides data concerning relative sensitivity of T. latifolia seedlings to the herbicides atrazine and paraquat, as well as the potential use of T. latifolia as a representative plant test species.     

Medium-term impacts of hydraulic clam dredgers on a macrobenthic community of the Adriatic Sea (Italy)

Hydraulic dredging targeting the bivalve Chamelea gallina in the northern and central Adriatic Sea has been taking place for over 30 years. In the period 2000–2001, 73 commercial dredgers harvested the resource within the sandy coastal area of the Ancona Maritime District (central Adriatic Sea). Despite this, no study aimed at investigating the impact of the fishery on the macrobenthic community of the area has ever been carried out. Sampling was done at 6 monthly intervals in an attempt to relate the impact of hydraulic dredging to different levels of fishing intensity. Data regarding two depth strata (4–6; 7–10 m) were analysed separately by means of permutational multivariate analysis of variance. The results revealed an overall condition of moderate disturbance within the benthic community, especially so within the 4–6 m depth stratum. The response of the benthic community to varying intensities of fishing activity was rapid, occurring within 6 months. Differences in the response of benthic community to differing intensities of fishing activity were found between the two depth strata considered. Significant differences in multivariate location of the benthic community were revealed between the three disturbance levels in both depth strata. Differences in multivariate dispersion were detected above a threshold level of fishing intensity, only within the shallow community. Differences were found between depth strata relating to species diversity and evenness, with significant differences between levels of fishing intensity being evident only within the 4–6 m depth stratum. The results emphasised that, even in a benthic community that is typical of a moderately disturbed environment, the effects of fishing on community structure were still discernible over and above the natural variation.