Environmental performance indicators for enhancing environmental management

Traditionally, environmental issues and concerns have been viewed as a constraint to businesses. This has resulted in environmental managers relying heavily on a reactive, compliance-based approach to justify change. Businesses are now recognizing that efficient management in the environmental arena can benefit the entire company and open new opportunities for increased profits. Managers have acknowledged that environmental issues can be integrated into daily business trends and activities. Not only does sound environmental management decrease liability, but also in current markets a “green” image can attract investors and customers. This article shows how one tool that progressive companies are focusing attention on—environmental performance indicators—is being used to convey the current status of environmental issues and improve the management of these issues for the benefit of the company as well as the environment.     

Refugee perceptions of the quality of healthcare: findings from a participatory assessment in Ngara, Tanzania

This article describes the findings of a participatory assessment of Burundian and Rwandan refugees' perceptions of the quality of health services in camps in Ngara, Tanzania. Taking a beneficiary-centred approach, it examines a collaborative effort by several agencies to develop a generic field guide to analyse refugees' views of healthcare services. The objective was to gather information that would contribute to significant improvements in the care offered in the camps. Although the primary focus was on healthcare, several broader questions considered other general apprehensions that might influence the way refugees perceive their healthcare. Findings indicated that while refugees in Ngara were generally satisfied with the quality of healthcare provided and healthcare promotion activities, recognition of some key refugee concerns would assist healthcare providers in enhancing services. With increasing need for refugee community participation in evaluating humanitarian assistance, this assessment has relevance both in the context of Ngara and beyond.     

Selective feeding by the mudskipper (<Emphasis Type="Italic">Boleophthalmus pectinirostris</Emphasis>) on the microalgal assemblage of a tropical mudflat

Temporal variation in abundance of the microphytobenthos on an estuarine mudflat in Hong Kong was investigated over a 13-month period. Abundance, in terms of both cell counts and chlorophyll- a (chl- a) concentration, of the diatom-dominated assemblage was higher (peak at 47 mg chl- a m ^-2 in January) in the cooler months than in the warmer months (minimum at 11 mg chl- a m ^-2 in August). Variation in surface density (range: 0.25–1.9 individuals m ^-2) of the herbivorous mudskipper Boleophthalmus pectinirostris was also temporally variable, with a broadly inverse pattern to that of the microphytobenthos. Comparison of the relative abundance of diatom species in the gut and on the mud surface using Strauss' linear selectivity index suggests significant size-selective feeding by B. pectinirostris. Diatoms with maximum lengths >50 µm were selectively ingested whereas smaller species were rejected. This critical diatom length is close to the average distance between branchiospines of the fish's gills, suggesting their involvement in a physical sieving process that is responsible for the size-selective feeding. Significant differences in feeding pattern exist between adult (>80 mm standard length) and juvenile fish. As a result of seasonal variations in density and selective removal of the larger diatoms, B. pectinirostris exerts a significant impact on the abundance and structure of the mudflat microphytobenthos.     

Genetic structure of giant clam (Tridacna derasa) populations from reefs in the Indo-Pacific

Large genetic differences were observed among the Great Barrier Reef (GBR), Fiji and Philippine populations of Tridacna derasa (Roding) sampled in 1989 and 1990 (Nei's unbiased genetic distance, D,=0.137 to 0.341). This result contrasted strongly with the low genetic distance (D=0.032) reported previously for the giant clam T. maxima over similar geographical scales. No significant genetic differentiation was observed among most populations from the GBR (mean D=0.007), consistent with the high gene exchange expected in this highly connected reef system. However, significant differentiation resulting from differences in the frequencies of less common alleles between the North-Central GBR and South GBR (Swain region) were observed. Historical isolation of blocks of the Central Indo-West Pacific from the GBR and present-day restrictions to gene exchange between the GBR, Fiji and the Philippines as a result of oceanographic current patterns, were thought to be responsible for the high degree of genetic differentiation of T. derasa populations. The relevance of these findings to clam mariculture and reef restocking are briefly discussed.Contribution No. 197 from the Marine Science Institute, University of the Philippines and Contribution No. 562 from the Australian Institute of Marine Science     

Characterisation of Acid Mine Drainage Using a Combination of Hydrometric, Chemical and Isotopic Analyses, Mary Murphy Mine, Colorado

The legacy of mining continues to affect stream water quality throughout the western United States. Traditional remediation, involving treatment of acid mine drainage from portals, is not feasible for the thousands of abandoned mines in the West as it is difficult and expensive. Thus, the development of new methods to address acid mine drainage is critical. The purpose of this study was two fold; to identify and test new tools to identify sources of metal pollution within a mine and to identify low-cost treatment alternatives through the use of these tools. Research was conducted at the Mary Murphy Mine in Colorado, a multiple-level underground mine which produced gold, silver, copper, lead and zinc from 1870 to 1951. Source waters and flowpaths within the mine were characterised using analysis of hydrogen and oxygen isotopes of water (water isotopes) in combination with solute analysis and hydrometric techniques. Hydrometric measurements showed that while discharge from a central level portal increased by a factor of 10 during snowmelt runoff (from 0.7 to 7.2 Ls^–1), Zn concentrations increased by a factor of 9 (from 3,100 to 28320gL^–1). Water isotopes were used as conservative tracers to represent of baseflow and snowmelt inputs in a hydrologic mixing model analysis. The results showed that less than 7% of peak discharge was from snowmelt. Within the mine, approximately 71% of the high-flow Zn loading was caused by a single internal stream characterised by extremely high Zn concentrations (270600gL^–1) and low pH (3.4). Somewhat surprisingly, hydrologic mixing models using water isotopes showed that new water contributed up to 79% of flow in this high-Zn source during the melt season. Diversion of this high-Zn source within the mine resulted in a decrease in Zn concentrations at the portal by 91% to 2,510gL^–1, which is lower than the base-flow Zn concentration. The results suggest that in some mines remediation efforts can be concentrated on specific areas within the mine itself. Using the characterisation techniques demonstrated in this study, problem areas can be identified and contaminated flows diverted or isolated. The results also suggest that it may be possible to dewater contamination areas, greatly reducing costs of remediation.     

Genetic consequences of long larval life in the starfish Linckia laevigata (Echinodermata: Asteroidea) on the Great Barrier Reef

Gene flow between populations of the asteroid Linckia laevigata (Linnaeus) was investigated by examining over 1000 individuals collected from ten reefs throughout the Great Barrier Reef (GBR), Australia, for genetic variation at seven polymorphic enzyme loci. Despite geographic separations in excess of 1000 km, Nei's unbiased genetic distance (0 to 0.003) and standardised genetic variation between populations (F _ST) values (mean 0.0011) were small and not significant. Genetic homogeneity among L. laevigata populations is consistent with the long-distance dispersal capability of its 28 d planktonic larval phase, and is greater than that observed for other asteroid species, including another high-dispersal species, Acanthaster planci, which has a 14 d larval phase. Variation within populations was also higher than previously recorded for asteroids (mean heterozygosity=0.384; number of alleles per locus ranged from 5.1 to 6.0 in each population). Among asteroids, dispersal ability is positively correlated with gene flow and levels of variation, and negatively correlated with levels of differentiation.     

Predator inspection behaviour in three-spined sticklebacks (<Emphasis Type="Italic">Gasterosteus aculeatus</Emphasis>): body size,local predation pressure and cooperation

The apparently maladaptive tendency of fish to approach and inspect potential predators has been explained in terms of useful information gathering or as a signal to the predator that it has been seen. We examined this behaviour in 16 populations of wild-caught stickleback (Gasterosteus aculeatus) from ponds with and without predatory perch (Perca fluviatilis). Three large and three small individuals per population were each exposed to three model predators differing in realism. A final cooperative treatment entailed pairing subjects with a second individual from the same population, but of the alternative size class, during predator presentation. As might be expected, predator inspection behaviour was much greater in the predator-sympatric populations, and only these fish increased their level of inspection as the models became incrementally more realistic. This suggests that reductions occur in the level of costly inspection behaviour in populations without predators. Subject body size had no effect on inspection effort, which suggests a limited role for experience (we assumed larger fish to be older than smaller fish), at least over the relative age differences utilized. However, small predator-sympatric fish were the only subjects to increase inspection significantly when in a cooperative context, perhaps reflecting the inherent value of a relatively larger partner in this context. These results confirm that levels of predator inspection are both population- and situation-dependent, suggesting a trade-off in the potential costs and benefits of this behaviour.Communicated by C. St. Mary     

No zone is always greener: variation in the performance of<Emphasis Type="Italic"> Fucus gardneri</Emphasis> embryos,juveniles and adults across tidal zone and season

The responses of the different stages of an organisms life-cycle to different environments can have important implications for their persistence in those habitats. The marine intertidal zone is considered among the most stressful of all marine environments, because daily exposure at low tide results in daily fluctuations in a range of important environmental factors. In this study we examined the link between daytime exposure and the performance of embryos, juveniles and adults of the seaweed Fucus gardneri across zones and seasons on San Juan Island, Washington, USA. Specifically we asked: (1) whether three measures of performance for F. gardneri: growth rates, surface area of reproductive tissue and survivorship differed between high- and mid-intertidal zones, and among months throughout the year and, then, (2) whether total daytime exposure within each zone each month was a good predictor of variation in these measures of performance. At our study site, seasonal differences in the timing of low tides result in long periods each day during summer of very harsh conditions (exposure to the air, high temperatures and low humidity) compared to winter when exposure to the air during the day is virtually absent. Contrary to the expectation of lower performance in the high zone, we found no consistent differences between zones over the entire year in any measure of performance for any stage. For nearly all traits, there were significant differences among months and, importantly, significant interactions between zone and month. Thus, for each stage there were some months when thalli in the high zone performed better and some months when thalli in the mid-zone performed better. Regressions between total daytime exposure and performance each month indicated some stage-specific effects. Larger thalli appeared more strongly affected by the amount of exposure per month; there were significant negative relationships between total daytime exposure and (1) growth rates of medium and large adults in the high zone and (2) the surface area of reproductive tissue of medium adults in the high zone and small adults in the mid-zone. The lowest survivorship for all stages occurred in the 2–3 months that followed summer, suggesting a cumulative effect of long daytime exposure in summer on survivorship. Post-settlement survivorship of embryos was very low throughout the year, with only 2 out of 5395 seeded zygotes surviving to a visible size. One-month post-settlement survivorship ranged from 0% to 16.7%, and there were no differences in the survivorship curves between high- and mid-intertidal zones for each cohort. Although it is often assumed that the performance of intertidal species is lower in high-intertidal zones because of exposure to environmental extremes for longer, our results do not support this paradigm. Instead, they indicate a complex and fluctuating pattern of variation in the performance of different stages of the F. gardneri life-cycle throughout the year in different intertidal zones.Communicated by M.S. Johnson, Crawley     

In-Vitro Determination of Arsenic Bioavailability in Contaminated Soil and Mineral Beneficiation Waste from Ron Phibun, Southern Thailand: A Basis for Improved Human Risk Assessment

The post-ingestion bioavailability of arsenic (As) in alluvial soil and mineral beneficiation waste from Ron Phibun, Nakhon Si Thammarat Province, Thailand has been investigated using a physiologically-based extraction test (PBET). The method utilises synthetic leaching fluids closely analogous to those of the human stomach and small intestine, upon which the leaching duration and ambient temperature of the experimental procedure are also directly based. Replicate analyses of Ron Phibun alluvium samples holding 1406 and 2123 g As g-1 respectively indicated an average stomach absorption of 11.2% (of total soil As). Gross absorption increased to 18.9% following translocation through a simulated small-intenstine regime. Higher gross absorption (35.7%) was recorded during PBET analysis of a flotation waste sample holding c. 2% total As. Within- and between-site variations of As bioavailability can principally be ascribed to mineralogical factors, notably the relative abundances of sulphide, arsenide, arsenate and oxide hosts within the soil/flotation waste matrix. The PBET provides a potentially valuable mechanism for refining risk assessments of sites subject to natural or anthropogenic As contamination. Through the substitution of total soil As values with input data which relate specifically to bioavailable As, risk calculations derived using established models such as the US-EPA package Risk Assistant may prove more realistic, thus facilitating improved cost-benefit analysis of site remediation options. Assessment of the relative human risks associated with potable water consumption and contaminated soil ingestion at Ron Phibun has signified that the latter could constitute a more significant As exposure pathway than recognised previously. Further evaluation of the precise soil ingestion levels of inhabitants residing on the As-rich alluvium which covers much of the district is, therefore, warranted.     

Lead, Zinc, Copper, and Cadmium in Fish and Sediments from the Big River and Flat River Creek of Missouri's Old Lead Belt

The Old Lead Belt of Missouri was a major lead-producing region for over a century. Several large tailings piles and other industrial wastes remain behind, though mining operations in the region ceased in 1972. Samples of stream sediments and fish were collected from established sites on the Big River and Flat River Creek over a 3-year period from 1998 to 2000 to evaluate ongoing remediation efforts and determine the current impact of residual mining wastes. Benthic sediments and fish taken in the vicinity of inactive industrial sites were found to contain elevated concentrations of Pb, Zn, Cu, and Cd. Concentrations of Pb and Zn in fillets of suckers and sunfish, as well as in whole bodies of sunfish, correlate well with metal concentrations observed in surficial sediments. The results of analyses provide valuable quantitative information regarding specific sources, current levels of contamination, potential risk to public health, and will allow more accurate assessment of continuing remediation efforts.