Seasonal variation in the degree of heterospecific association of two syntopic hyraxes (<Emphasis Type="Italic">Heterohyrax</Emphasis><Emphasis Type="Italic">brucei </Emphasis>and <Emphasis Type="Italic">Procavia capensis</Emphasis>) exhibiting synchronous parturition

Adult rock hyrax (Procavia capensis) and bush hyrax (Heterohyrax brucei) allocate much of their surface activity to being vigilant for vertebrate predators. Individuals of the two species associate for thermoregulatory basking on rock outcrops (koppies) and, in the Matobo National Park, Zimbabwe, frequently constitute heterospecific groups that produce offspring synchronously. Exposure to predators during basking is thought to put a high premium on vigilance, particularly during the presence of dependent offspring in nurseries. We predicted, therefore, an increase in the association of the two species of hyraxes when offspring were present because this would lead to larger groups, thus enhancing the ability to detect predators. Koppie aggregations of hyraxes were classified as homospecific or heterospecific according to basking group composition. Heterospecific association increased when offspring were present, and heterospecific groups were larger than homospecific ones. Fifty-one percent of nurseries were heterospecific for adults/subadults. During the pre-weaning phase (<2 months after birth), 85% of P. capensis and 65% of H. brucei juveniles were in nurseries of heterospecific basking groups. Heterospecific groups had more offspring than homospecific groups. Juvenile mortality is most evident after young are weaned and heterospecific associations break down. Heterospecific aggregation, through increased group size, may result in a higher probability of avoiding predators, thereby reducing the vulnerability of young.     

Metal survey of the marine clam Pitar morrhuana collected near a Rhode Island (USA) electroplating plant

Benthic fauna were collected from 17 stations in mid-Narragansett Bay, Rhode Island, during September 1973 from the vicinity of the recently-closed Quonset Point electroplating facility. Despite repeated sampling, most of the 14 species of molluscs taken, including the widgeon clam Pitar morrhuana, were absent from stations in the immediate vicinity of plant outfalls. In general, P. morrhuana captured near outfall sites exhibited high moisture content and elevated body burdens of silver, cadmium, cobalt, chromium, copper, iron, manganese, nickel, lead, and zinc compared to clams of similar size from more distant stations. Observed changes in metal concentrations and moisture content of P. morrhuana were probably attributable to plant operations during the preceding 30 years.     

Methylalkylpyrazines in aposematic insects,their hostplants and mimics

Summary Adults of forty-five aposematic insect species from four orders, and/or, in eight cases, their early stages, were examined for the presence of 2-methoxy-3-alkylpyrazines by coupled gas chromatography/mass spectrometry. The survey also included eight cryptic and related species and six unrelated mimics, twelve selected hostplants of those herbivores that had proved positive for such pyrazines, and nine well known toxic plants. Positive results were as follows: aposematic adult species, 26 (58 %); obscurely coloured species, 1 (12.5%); mimics, 2 (33%); host-plants, 5 (42%); well-known toxic plants, 4 (44%). Among the taxonomic groups, these pyrazines were found in the lepidopteran families and subfamilies Papilionidae, Danainae, Heliconiinae, Acraeinae, Zygaenidae and Arctiidae, and among the Coleoptera, in the Lycidae, Cantharidae, Endomychidae, Coccinellidae, Oedemeridae and Meloidae. Single cases of the occurrence of these pyrazines were also detected in the Hemiptera (Cercopidae) and Orthoptera (Pyrgomorphidae). Mimics were found with and without the pyrazines. Among the plants they were detected in Aristolochiaceae, Asclepiadaceae, Asteraceae, Papaveraceae, Passifloraceae, Solanaceae and Urticaceae. Some aposematic and phytophagous insects apparently sequester pyrazines from their hostplants whereas others, particularly the predatory species, manufacture these substancesde novo. Alerting signals in general are discussed.     

Lake destratification and speciation of iron and manganese

A long-term study of the effect of artificial aeration (destratification) of a water storage dam upon the speciation of iron and manganese in the dam waters has been undertaken. Separation of dam samples into soluble and insoluble forms by selective membrane filtration was undertaken before using the techniques of EPR spectroscopy, ion chromatography and gel filtration to assess the speciation of soluble species, and selective extraction and surface analysis (ESCA, SIMS and SEM) techniques to determine the speciation of particulate iron and manganese species. The percentages of soluble iron and manganese before (1983–85) and after (1986–88) artificial aeration are compared for the periods Jan–Dec, Jan–Mar, and Jun–Aug at three depths 6 m, 15 m and 0.5 m above the dam base, to assess the importance of seasonal changes in the various depths of the dam. Although aeration had an initial marked reduction in levels of soluble iron and manganese at all depths of the dam, the concentrations of these mtals showed a steady increase over succeeding years. Analysis of the figures over summer and winter periods shows that the reduction of soluble iron was maintained in summer, but not during winter. Upon aeration, the initial reduction of soluble manganese concentration was maintained in succeeding years in the epilimnic regions of the dam, but not in the hypolimnion. Statistical analysis of data has been undertaken to correlate the changes in relationship between the various forms of iron and manganese with the advent of aeration.     

A longitudinal assessment of the aquatic macroinvertebrate community in the channelized lower Missouri River

We conducted an aquatic macroinvertebrate assessment in the channelized reach of the lower Missouri River, and used statistical analysis of individual metrics and multimetric scores to identify community response patterns and evaluate relative biological condition. We examined longitudinal site differences that are potentially associated with water qualityrelated factors originating from the Kansas City metropolitan area, using data from coarse rock substrate in flowing water habitats (outside river bends), and depositional mud substratein slack water habitats (dike fields). Three sites above rivermile (RM) 369 in Kansas City (Nebraska City, RM = 560; St. Joseph, RM = 530; Parkville, RM = 377) and three below (Lexington, RM = 319; Glasgow, RM = 228; Hermann, RM = 94) were sampled with rock basket artificial substrates, a qualitative kicknet method, and the Petite Ponar. We also compared the performance of the methods used. A total of 132 aquatic macroinvertebrate taxa were collected from the lower Missouri River; one third of these taxa belonged to the sensitiveEPOT insect orders (Ephemeroptera, Plecoptera, Odonata, and Trichoptera). Rock baskets had the highest mean efficiency (34.1%) of the methods, and the largest number of taxa was collected by Ponar (n = 69) and kicknet (n = 69) methods. Seven of the 15 metrics calculated from rock basket data, and five ofthe nine metrics calculated from Ponar data showed highly significant differences (ANOVA, P < 0.001) at one or more sitesbelow Kansas City. We observed a substantial reduction in net-spinning Trichoptera in rock habitats below Kansas City (Lexington), an increase in relative dominance of Oligochaeta in depositional habitats at the next site downstream (Glasgow), and lower relative condition scores in rock habitat at Lexingtonand depositional habitat at Glasgow. Collectively, these data indicate that some urban-related impacts on the aquatic macroinvertebrate community are occurring. Our results suggest that the methods and assessment framework we used in this studycould be successfully applied on a larger scale with concurrentwater and sediment chemistry to validate metrics, establish impairment levels, and develop a specific macroinvertebrate community index for the lower Missouri River. We recommend accomplishing this with longitudinal multi-habitat sampling at a larger number of sites related to all potential sources of impairment, including major tributaries, urban areas, and point sources.     

Pilot study on the contamination of drinking water by organotin compounds from PVC materials

Raw and treated water samples and tap water samples from four to six houses located on distribution lines where PVC pipe/tubing had been recently installed were collected in five Canadian municipalities for the analysis of organotin compounds. After derivatisation with sodium tetraethylborate the ethylated organotin compounds were extracted with hexane and analysed by gas chromatography-microwave induced plasma atomic emission spectrometry using a wavelength (326.234 nm) specific for tin. Organotin compounds, mainly methyltin and dimethyltin at concentrations ranging respectively from 0.5 to 257 ng Sn/L and from 0.5 to 6.5 ng Sn/L, were detected in samples from ten of the twenty-two houses. No organotin compounds were detected in raw water or treated water leaving the treatment plant, indicating that the organotin compounds were leaching into the water from some component of the distribution system.     

Identification of a novel β0 - thalassaemia mutation in a greek family and subsequent prenatal diagnosis

We present a case in which a Greek couple was considered not to be at risk of having children with homozygous β-thalassaemia, an assessment based largely on the father's belief that he carried α-thalassaemia. After their first child was diagnosed with homozygous β-thalassaemia, the case was re-assessed and both parents were shown to have the haematological profile of β-thalassaemia trait. Screening for the common Mediterranean mutations demonstrated that the mother carries the IVS-1 nt 110 G→A β⁺ -thalassaemia mutation. Direct nucleotide sequencing of PCR-amplified DNA revealed that the father carries a novel β⁰-thalassaemia mutation, frameshift codons 9/10 (+T). The couple's second pregnancy was terminated after prenatal testing revealed that the fetus had inherited both parental mutations. This case illustrates the need to confirm the carrier status of individuals prior to assessing their genetic risks, and highlights the importance of being able to identify rare or novel β-thalassaemia mutations.     

Climate change and mining in Canada

Climate is an important component of the operating environment for the Canadian mining sector. However, in recent years mines across Canada have been affected by significant climatic hazards, several which are regarded to be symptomatic of climate change. For the mining sector, climate change is a pressing environmental threat and a significant business risk. The extent to which the mining sector is able to mitigate its own impact and adapt to climate change will affect its long-term success and prosperity, and have profound economic consequences for host communities. This paper draws upon case studies conducted with mining operations in Canada involving in-depth interviews with mining professionals and analysis of secondary sources to characterize the vulnerability of the Canadian mining industry to climate change. Five key findings are discussed: i) mines in the case studies are affected by climate events that are indicative of climate change, with examples of negative impacts over the past decade; ii) most mine infrastructure has been designed assuming that the climate is not changing; iii) most industry stakeholders interviewed view climate change as a minor concern; iv) limited adaption planning for future climate change is underway; v) significant vulnerabilities exist in the post-operational phase of mines. This paper argues for greater collaboration among mining companies, regulators, scientists and other industry stakeholders to develop practical adaptation strategies that can be integrated into existing and new mine operations, including in the post-operational phase.     

Book reviews

Toward Sustainable Communities: resources for citizens and their governments. Mark Roseland with Maureen Cureton & Heather Wornell, 1998, Gabriola Island, New Society Publishers, ISBN 0 86571 374 X, $18.95

First Mover Advantage by Eco-efficiency: local incentives for environment and employment.. C. Erdmunger & S. Schreckenberger, 1998, Freiburg, ICLEI, DM30

Agendas for Sustainability: environment and development into the twenty-first century. Mary Macdonald, 1998, London, Routledge, ISBN 0 415 15491X, £55.00 (hbk)

Women, Population and Global Crisis: a political-economic analysis. Asoka Bandarage, 1997, London, Zed Books, ISBN 1 85649 428 4, £15.95 (pbk)

Spirit of the Environment: religion, value, and environmental concern. David Cooper & Joy Palmer (Eds), 1998, London, Routledge, ISBN 0 4151 4202 4, £12.99 (pbk)

Environmental Transition in Nordic and Baltic Countries. Hans Aage (Ed.), 1998, (New Horizons in Environmental Economics). Cheltenham, UK and Northampton, MA, USA, Edward Elgar, ISBN 1 85898 629 X

Sustainability Indicators: measuring the immeasurable. Simon Bell & Stephen Morse, 1999, London, Earthscan Publications, 175 pp. ISBN 1 85383 498 X, LE14.95 (pbk)

The Economics of Road Transport Regulation. Erik Verhoef, Cheltenham, Edward Elgar 1996, 265 pp. ISBN 1 85898 364 9, £55.00

The Water Crisis. Julie Stauffer, London, Earthscan, 1998, ISBN 185383 436X, £12.95 (pbk)