Distribution of Mytilus edulis, M. galloprovincialis, and their hybrids in open-coast populations of mussels in southwestern England

The distribution of Mytilus edulis Linnaeus, M. galloprovincialis Lamarck, and their hybrids was examined in mussel populations in southwest England in 1996 and 1998. This is a region where both parental taxa and populations containing large numbers of hybrids co-occur yet a fine-scale mapping of the hybrid populations has not been conducted. In this study the geographic distribution of hybrid populations was determined in southwest England over 360 km of coast from Tintagel Castle in north Cornwall to Beer in south Devon. Sample localities were spaced from 5 to 20 km apart. Genotypes for individual mussels were determined using PCR to amplify a size polymorphism at the Glu-5' locus that is completely differentiated between M. edulis and M. galloprovincialis. Hybrid populations, characterized by high frequencies of individuals with heterozygous genotypes and a pattern of decreasing frequency of M. edulis alleles with increasing shell length, were continuously distributed along 180 km of open coast in southwest England. This "hybrid patch" was bordered at one end by geographically extensive populations of pure M. edulis and at the other end by nearly pure populations of M. galloprovincialis. Strong natural selection in hybrid populations results in a decline in the frequency of M. edulis alleles with increasing size. Wave-exposure has previously been implicated as the agent producing this pattern of selection, but in the present study the relationship between allele frequency and body size was not correlated with variation in wave shock intensity among localities within the hybrid zone. The transition between hybrid populations and those containing pure populations of M. edulis or M. galloprovincialis is abrupt which suggests that coastal circulation patterns may provide strong barriers to larval dispersal which accounts for the position and maintenance of the hybrid zone.     

Complementary benefits of tourism and hunting to communal conservancies in Namibia

Tourism and hunting both generate substantial revenues for communities and private operators in Africa, but few studies have quantitatively examined the trade‐offs and synergies that may result from these two activities. We evaluated financial and in‐kind benefit streams from tourism and hunting on 77 communal conservancies in Namibia from 1998 to 2013, where community‐based wildlife conservation has been promoted as a land‐use that complements traditional subsistence agriculture. We used data collected annually for all communal conservancies to characterize whether benefits were derived from hunting or tourism. We classified these benefits into 3 broad classes and examined how benefits flowed to stakeholders within communities under the status quo and under a simulated ban on hunting. Across all conservancies, total benefits from hunting and tourism increased at roughly the same rate, although conservancies typically started generating benefits from hunting within 3 years of formation as opposed to after 6 years for tourism. Disaggregation of data revealed that the main benefits from hunting were income for conservancy management and food in the form of meat for the community at large. The majority of tourism benefits were salaried jobs at lodges. A simulated ban on trophy hunting significantly reduced the number of conservancies that could cover their operating costs, whereas eliminating income from tourism did not have as severe an effect. Given that the benefits generated from hunting and tourism typically begin at different times in a conservancy's life‐span (earlier vs. later, respectively) and flow to different segments of local communities, these 2 activities together may provide the greatest incentives for conservation on communal lands in Namibia. A singular focus on either hunting or tourism would reduce the value of wildlife as a competitive land‐use option and have grave repercussions for the viability of community‐based conservation efforts in Namibia, and possibly other parts of Africa.     

Sustaining recycling: identification and application of limiting factors in kerbside recycling areas

SUMMARY

Levels of recycling in the UK are substantially poorer than other European countries and American states. One explanation for low participation rates, has been the failure by some local authorities to bridge the gap between people's attitudes and behaviour. Research has shown that a gap exists between people's environmental attitudes and action. Previous experiments have employed antecedent and consequence conditions to influence the factors that limit environmental action, in an attempt to close the gap between attitudes and behaviour. This paper reports on the research carried out by Cardiff University and De Montfort University, which has attempted to identify and manipulate the factors that influence whether or not someone recycles in the Cities of Cardiff and Leicester. Different experiments were applied to different socio-demographic groups. Questionnaires were used to assess attitudes and behaviour before and after the implementation of a series of experiments. The research indicated that the interventions were more effective at increasing levels of recycling among existing recyclers rather than prompting non-recyclers to start recycling. The interventions differed in terms of their effect upon participation in particular sociodemographic groups. Key factors identified from the research could be equally applicable to other contexts of individual environmental action.     

Biorhythms and the incidence of industrial accidents

Biorhythm critical days have been suggested as a possible cause of industrial accidents by a number of authors, although the empirical evidence is confusing. This study examined all industry-related accidents in a large Australian timber milling organization over a 15-month period to see if the implied relationships existed. A variety of biorhythm critical day definitions and accident types were analyzed, but no significant results were obtained, suggesting that the proposed theory did not hold in this case.     

Individual differences in behavioral compliance to warnings representing varying degrees of threat

Research regarding warning compliance has often emphasized the physical aspects of the warning itself. Here, we examine the role of the perceiver in sensation seeking and health orientation as individual difference variables that affect behavioral compliance to a health warning. The experiment used a laboratory-based simulation of a chemistry demonstration that has been used in previous warnings research. In addition, however, individual difference effects of sensation seeking and health orientation were investigated. Among the significant findings were a significant interaction between condition assignment and sensation seeking on compliance outcome and a significant interaction between condition and health orientation. These results indicate that individual difference variables represent significant influences on the degree to which persons comply with warnings.     

Coal and peat in the sub-Saharan region of Africa

Increased energy demand as a result of growth in population, trends to sedentation and urbanization, and the desire for improvement in living standards, coupled with apparent climatic changes, are reducing fuelwood availability and contributing to deforestation and desertification in the sub-Saharan countries. In 14 of those countries, the transport, industrial, and electric power generation sectors are all dependent on imported petroleum products for their energy needs with resultant balance of trade and debt-servicing problems. Coal and peat are essentially unused and in some cases unknown in sub-Saharan Africa. However, they might comprise valuable alternative energy sources in some or all of the developing nations of the region. The eleven countries considered in this appraisal reportedly contain coal and peat. On the basis of regional geology, another five countries might also contain coal-bearing rocks. If the resource potential is adequate, coal and peat might be utilized in a variety of ways including substituting for fuelwood, generating electricity, supplying process heat for local industry and increasing agricultural productivity.     

Chronic Toxicity of 1080 and its Implications for Conservation Management: A New Zealand Case Study

Sodium monofluoroacetate (1080) is a mammalian pesticide used in different parts of the world for the control of mammalian pest species. In New Zealand it is used extensively and very successfully as a conservation management tool for the control of brushtail possums (Trichosurus vulpecula) – an introduced marsupial that has become a substantial agricultural and conservation management pest. Possums pose a threat to cattle farming in New Zealand as they are a vector for bovine tuberculosis. In protected natural areas, possum browsing is responsible for large scale defoliation of native vegetation. As with many other pesticides, there has been some degree of popular concern about the use of this toxin and its safety, with particular reference to non-target effects. These concerns have been associated with potential non-target effects on human health, and the health of animals of recreational value (e.g., hunting dogs and game animals). This has led to the development of a strong “anti-1080” lobby in New Zealand. In contrast, this study encompasses a science-based risk analysis focusing on the potential risks to non-target native wildlife with a particular focus on chronic toxicity. It finds that there is evidence that 1080 may have endocrine disrupting capabilities (with potential relevance for non-target wildlife) but that this still needs more detailed investigation. This can be clarified by further targeted research. Further research is also needed to test the degradation rates of 1080 and its breakdown products at ecologically-relevant temperatures (i.e., winter stream temperatures – below 11 °C). Such research may demonstrate that some adjustment to 1080 risk management is warranted in New Zealand, or it may help to put to rest the current controversy over the use of this cost effective conservation management tool.     

Nitrogen use efficiency: A potential performance indicator and policy tool for dairy farms

Escalating fertilizer and feed costs, declining product prices, and increasing regulations to reduce environmental pollution have created new pressures to improve nutrient use in agricultural production. This study provides an overview of factors and processes that impact nitrogen use efficiency (NUE) in dairy production, identifies practices that may bridge gaps between actual-NUE obtained on commercial farms and potential-NUE obtained under experimental conditions, and explores the possibility of using NUE as a performance indicator and policy tool for dairy production. Actual feed-NUE varies from 16% to 36% and is impacted by of a range of dairy practices; manure/fertilizer-NUE varies from 16% to 77% and is very site-specific; and whole-farm NUE varies from 8% to 64% and declines as stocking rates increase. Optimal stocking rate and manure nitrogen (N) crediting can enhance NUE, increase farm profits, and reduce N loss from dairy farms. NUE could be used to further engage dairy producers in collaborative assessments of gaps between their actual N use and the biological potential of N use, to develop performance goals for N use in various production components, and to monitor and evaluate the impacts of alternative feed, manure and fertilizer management practices on N use, profitability, and environmental outcomes.     

Perceptions of a Nearby Exurban Protected Area in South Carolina,United States

To address the dearth of literature on the relations between local residents in urban areas and nearby higher-order exurban protected areas, this study examined the perceptions of Columbia (South Carolina) residents toward Congaree National Park. Mail-out survey results from a random sample of 455 adult residents showed positive overall attitudes toward the park, although this did not extend to a desire to personally volunteer in park activities. Cluster analysis on the basis of seven perceptual statements produced three groups: “very enthusiastic park supporters” (VEPS), accounting for one fourth of the sample; “less enthusiastic park supporters” (LEPS), accounting for approximately one half of the sample; and “ambivalents” (AMBS), accounting for the rest. The AMBS tend to be younger than members of the other clusters and have higher income, but enthusiasm was more clearly related to high levels of interaction and awareness relative to the park. Managerial implications of the study are considered, including the need to encourage higher levels of park awareness and visitation, as well as more ecologically responsible behavior, among residents of the greater Columbia urban area.