Estimating the Density of Honeybee Colonies across Their Natural Range to Fill the Gap in Pollinator Decline Censuses

Abstract: Although pollinator declines are a global biodiversity threat, the demography of the western honeybee (Apis mellifera) has not been considered by conservationists because it is biased by the activity of beekeepers. To fill this gap in pollinator decline censuses and to provide a broad picture of the current status of honeybees across their natural range, we used microsatellite genetic markers to estimate colony densities and genetic diversity at different locations in Europe, Africa, and central Asia that had different patterns of land use. Genetic diversity and colony densities were highest in South Africa and lowest in Northern Europe and were correlated with mean annual temperature. Confounding factors not related to climate, however, are also likely to influence genetic diversity and colony densities in honeybee populations. Land use showed a significantly negative influence over genetic diversity and the density of honeybee colonies over all sampling locations. In Europe honeybees sampled in nature reserves had genetic diversity and colony densities similar to those sampled in agricultural landscapes, which suggests that the former are not wild but may have come from managed hives. Other results also support this idea: putative wild bees were rare in our European samples, and the mean estimated density of honeybee colonies on the continent closely resembled the reported mean number of managed hives. Current densities of European honeybee populations are in the same range as those found in the adverse climatic conditions of the Kalahari and Saharan deserts, which suggests that beekeeping activities do not compensate for the loss of wild colonies. Our findings highlight the importance of reconsidering the conservation status of honeybees in Europe and of regarding beekeeping not only as a profitable business for producing honey, but also as an essential component of biodiversity conservation.     

Buying green: the crucial role of public authorities

Abstract

A strategic approach to local sustainability assessment requires that sustainability implications of proposed policies, plans and programmes are evaluated. These evaluations need to critically consider organizational structures, processes and outcomes. The establishment of ‘communities of practice’, groups or networks of practitioners with shared interests, is a helpful mechanism for facilitating change in a wide range of organizations. This paper analyses the potential for communities of practice to contribute to the implementation of sustainability assessments by local government. Focusing on Sutherland Shire Council in Sydney, Australia, this paper presents the findings of a project that engaged practitioners in the design of a sustainability assessment system. The establishment of communities of practice helped to break down the ‘silos’ created by institutional divides within local government, but this approach also raises challenges in maintaining momentum and overcoming political agendas.     

Distribution of planktonic bacteria capable of degrading sodium dodecyl sulphate (SDS) in a polluted South Wales river

The temporal and geographical distributions of planktonic bacteria, and their ability to degrade sodium dodecyl sulphate (SDS) (AS(+) phenotype), in a polluted South Wales river, is reported for five sites source to estuary sampled during a one-year period. The annual mean prevalence of AS(+) isolates at all sites was 8.1-16.0% of the total number of isolates, and these values were not altered by including SDS in culture media. Although the proportion of AS(+) isolates in clean water at the source was not significantly different to that of polluted sites, the AS(+) cell density was lower at the source because of its lower overall numbers. The percentage of AS(+) isolates in estuarine water was higher than at the three polluted mid-river sites, but when cell numbers were taken into account, the AS(+) cell density was the same at all polluted sites including the estuary. There was no correlation between percentage of AS(+) and either BOD or oxygen concentration, but AS(+) isolates were significantly more prevalent at the end of summer. Of the AS(+) isolates, more than half contained constitute alkysulphate enzymes, the remainder being induced or repressed by SDS; the relative proportions of enzyme regulatory type did not vary significant between sites or at different sampling times.     

Allozyme variation in populations of the dog-whelkNucella lapillus (Prosobranchia: Muricacea) from the South West peninsula of England

Four populations of the predatory gastropodNucella lapillus were sampled at sites around the South West Peninsula of England in 1986, and analysed for allozyme variation at 18 enzyme loci. Two of these loci, Gpd-1 andHk-1, exhibited sex-specific phenotypes. An absolute locus association was observed between two other loci,Mdh-1 andEst-3. This association was only found at one site (Prawle), and it is suggested that the presence of chromosomal polymorphisms could explain this finding. As a measure of overall similarity, Nei's genetic identity statistic,I, was calculated; the mean for all populations was 0.989, with values ranging from 0.981 to 0.997. Although similar on this gross level, considerable interpopulation variation was evident. Observed mean heterozygosity (per locus) ranged from 0.043 to 0.104 (mean 0.074). Populations differed also in the loci at which significant heterozygote deficits were seen (of the seven deficits recorded only those at thePep-1 locus were consistent across sites) and in the presence of rare alleles undetected elsewhere. The variation observed showed no correlation to shell morphology or geographical distance and confirmed the conclusion that species of the genusNucella show considerable disjunct variation.     

NORTHWESTERN ONTARIO RIVER DIMENSIONS1

ABSTRACT: Biophysical and socioeconomic effects are identified in reservoir, downstream, division channel, and receiving water body areas. Overall, the projects have been socially useful, especially from the perspective of hydroelectric, log driving, and economic development benefits. However selected socially inequitable aspects of the projects and other problems related to erosion, turbidity, multiple resource use, failure to clear trees, and heritage resource losses are identified. Suggestions for planning similar projects are presented.     

Regulation for environmental protection: The Nanticoke industrial complex,Ontario, Canada

This assessment of the environmental protection regulatory system for the $2.2 billion iron and steel plant, oil refinery, and thermal generating station composing the core of the greenfield Nanticoke industrial complex is based upon: the use of governmental and industrial research in project management; technology and institutional arrangements for environmental protection; evidence of environmental changes to date; analysis of government and industrial approval files; and interviews with government, industry, and interest group representatives. Planning, regulation, and management have been reasonably efficient and effective to the beginning of the operational stage for all three major industries as of spring 1980. Of major future concern, however, is management of the cumulative and synergistic impacts of the industries and associated development on air quality as well as the lands, waters, and sensitive ecosystems of the nearby Lake Erie coast. Continuous monitoring, more comprehensive research, and better overall coordination of government, industrial, and public interests are required if Nanticoke benefits are to be achieved without undue cost to pre-project resource users within and outside the Haldimand-Norfolk region.     

Land loss in coastal Louisiana (U.S.A.)

This paper examines causes and consequences of wetland losses in coastal Louisiana. Land loss is a cumulative impact, the result of many impacts both natural and artificial. Natural losses are caused by subsidence, decay of abandoned river deltas, waves, and storms. Artificial losses result from flood-control practices, impoundments, and dredging and subsequent erosion of artificial channels. Wetland loss also results from spoil disposal upon wetlands and land reclamation projects.Total land loss in Louisiana's coastal zone is at least 4,300 ha/year. Some wetlands are converted to spoil banks and other eco-systems so that wetland losses are probably two to three times higher. Annual wetland losses in the Barataria Bay basin are 2.6% of the wetland area. Human activities are the principal determinants of land loss. The present total wetland area directly lost because of canals may be close to 10% if spoil area is included. The interrelationship between hydrology, land, vegetation, substrate, subsidence, and sediment supply are complicated; however, hydrologic units with high canal density are generally associated with higher rates of land loss and the rate may be accelerating.Some cumulative impacts of land loss are increased saltwater intrusion, loss of capacity to buffer the impact of storms, and large additions of nutrients. One measure of the impact is that roughly $8–17 × 10⁶ (U.S.A.) of fisheries products and services are lost annually in Louisiana.Viewed at the level of the hydrologic unit, land loss transcends differences in local vegetation, substrate, geology, and hydrology. Land management should therefore focus at that level of organization. Proper guideline recommendations require an appreciation of the long-term interrelations of the wetland estuarine system.     

Modeling the relationship between development and storm water and nutrient runoff

The EPA Storm Water Management Model was used to model the effects of urban and agricultural development on storm water runoff from uplands bordering a Louisiana swamp forest. Using this model, we examined the effects of changing land use patterns. By 1995 it is projected that urban land on the uplands bordering the swamp will increase by 321 percent, primarily at the expense of land currently in agriculture. Simulation results indicate that urbanization will cause storm water runoff rates to be up to 4.2 times greater in 1995 than in 1975. Nutrient runoff will increase 28 percent for nitrogen (N) and 16 percent for phosphorus (P) during the same period. The environmental effects of these changes in the receiving swamp forest are examined.     

Modeling hydrology and eutrophication in a Louisiana swamp forest ecosystem

The EPA Storm Water Management Model (1971) was used to model hydrodynamics, nutrient dynamics, and eutrophication in a Louisiana swamp forest ecosystem. The present system of canals and spoil banks in the swamp causes impoundment of swamp areas and does not optimize discharge from the swamp forest. Simulations showed that hydraulics could be managed to increase discharge rates to the lower estuary (22 percent), to increase productivity of the swamp forest (100 percent), and to decrease lake eutrophication (43 percent). This could be done by removing spoil banks in the swamp and allowing upland runoff to pass through the backswamp.     

Pesticide residues in freshwater and marine zooplankton: a review

A review of the scientific literature on pesticide residues in freshwater and marine zooplankton indicates that despite the great number of pesticides in current use, only residues of the persistent organochlorine insecticides, many of which have been restricted or removed from general use in North America, have been determined. Much of this information is outdated. In addition, with the exception of the Great Lakes on which limited information is available, reports on residues in freshwater zooplankton are rare. Information on residues of the newer, less persistent but heavily used pesticides is lacking. As an alternative to field sampling and chemical analysis of endemic populations of zooplankton, scientists have modeled the bioaccumulation of pesticides in zooplankton using either laboratory microcosms or mathematical equations. However, the extent and importance of trophic transfer to higher food levels through this intermediary group of organisms is still controversial. In addition, the relationship between accumulation of pesticides and toxicity to zooplankton remains unresolved.