Evaluating betterment projects

In the past decade Australia has experienced a series of large‐scale, severe natural disasters including catastrophic bushfires, widespread and repeated flooding, and intense storms and cyclones. There appears to be a prima facie case for rebuilding damaged infrastructure to a more disaster resilient (that is, to ‘betterment’) standard. The purpose of this paper is to develop and illustrate a consistent and readily applied method for advancing proposals for the betterment of essential public assets, which can be used by governments at all levels to determine the net benefits of such proposals. Case study results demonstrate that betterment investments have the potential to deliver a positive economic return across a range of asset types and regions. Results, however, are highly sensitive to underlying assumptions; in particular the probability of the natural disaster affecting the infrastructure in the absence of betterment.     

Mutualist-induced morphological changes enhance growth and survival of corals

Species interactions can induce morphological changes in organisms that affect their subsequent growth and survival. In Moorea, French Polynesia, epibiotic gammaridean amphipods induce the formation of long, branch-like coral “fingers” on otherwise flat, encrusting, or plating Montipora coral colonies. The fingers form as corals encrust tubes built by the amphipods and lead to significant changes in colony morphology. This study examines the costs and benefits of this association to the amphipods and corals and demonstrates that the interaction is a mutualism. Amphipods gain protection from predators by living within corals, and corals benefit by enhanced growth and survival. Benefits to the coral arise through direct effects due to the amphipods’ presence as well as through benefits derived from the altered colony morphology. This study demonstrates that induced morphological plasticity can be a mechanism for facilitation, adding to our knowledge of the roles mutualism, and phenotypic plasticity play in ecology.     

The role of images of conspecifics as visual cues in the development and behavior of larval anurans

Tadpoles can alter their behavior, morphology, and life history in response to habitat change. Although chemical signals from conspecifics or predators play an important role in tadpole habitat assessment, little is known about the role of visual cues and the extent to which tadpoles rely on their vision for intraspecific social assessment. The aim of our experiments was to determine whether larval anurans use visual images of other tadpoles as indicators of density and to analyze how, and to what extent, images of conspecifics alone affect tadpole development, growth, and behavior. To assess this, we raised both Rana sylvatica and Bufo americanus tadpoles in aquaria with either quarter- or half-mirrored walls. Both physically increased density and increased density simulated with mirrors decreased tadpole growth and developmental rates, and increased activity in Rana tadpoles. Bufo tadpoles did not significantly alter their growth and development in response to visually increased density. Only true, i.e., physically, increased density had an effect on growth and activity in Bufo tadpoles. Our data show that images of conspecifics are used as visual cues by Rana tadpoles and can induce phenotypically plastic changes in several traits. This response to visual cues is taxon-specific. An erratum to this article can be found at     

Variability in grazer-mediated defensive responses of green and red macroalgae on the south coast of South Africa

Variabilities in the responses of several South African red and green macroalgae to direct grazing and the responses of one green alga to cues from grazers were tested. We used two feeding experiments: (1) testing the induced responses of three red and one green algae to direct grazing by mesograzers and (2) a multi-treatment experiment, in which the direct and indirect effects of one macrograzer species on the green alga Codium platylobium were assessed. Consumption rates were assessed in feeding assays with intact algal pieces and with agar pellets containing non-polar extracts of the test algae. Defensive responses were induced for intact pieces of Galaxaura diessingiana, but were not induced in pellets, suggesting either morphological defence or chemical defence using polar compounds other than polyphenols. In contrast, exposure to grazing stimulated consumption of Gracilaria capensis and Hypnea spicifera by another grazing species. In the multi-treatment experiment, waterborne cues from both grazing and non-grazing snails induced defensive algal traits in C. platylobium. We suggest that inducible defences among macroalgae are not restricted to brown algae, but that both the responses of algae to grazers and of grazers to the defences of macroalgae are intrinsically variable and complex.     

Carbon sequestration in California agriculture, 1980-2000.

To better understand agricultural carbon fluxes in California, USA, we estimated changes in soil carbon and woody material between 1980 and 2000 on 3.6 x 10(6) ha of farmland in California. Combining the CASA (Carnegie-Ames-Stanford Approach) model with data on harvest indices and yields, we calculated net primary production, woody production in orchard and vineyard crops, and soil carbon. Over the 21-yr period, two trends resulted in carbon sequestration. Yields increased an average of 20%, corresponding to greater plant biomass and more carbon returned to the soils. Also, orchards and vineyards increased in area from 0.7 x 10(6) ha to 1.0 x 10(6) ha, displacing field crops and sequestering woody carbon. Our model estimates that California's agriculture sequestered an average of 19 g C x m(-2) x yr(-1). Sequestration was lowest in non-rice annual cropland, which sequestered 9 g C x m(-2) x yr(-1) of soil carbon, and highest on land that switched from annual cropland to perennial cropland. Land that switched from annual crops to vineyards sequestered 68 g C x m(-2) x yr(-1), and land that switched from annual crops to orchards sequestered 85 g C x m(-2) x yr(-1). Rice fields, because of a reduction in field burning, sequestered 55 g C x m(-2) x yr(-1) in the 1990s. Over the 21 years, California's 3.6 x 10(6) ha of agricultural land sequestered 11.0 Tg C within soils and 3.5 Tg C in woody biomass, for a total of 14.5 Tg C statewide. This is equal to 0.7% of the state's total fossil fuel emissions over the same time period. If California's agriculture adopted conservation tillage, changed management of almond and walnut prunings, and used all of its orchard and vineyard waste wood in the biomass power plants in the state, California's agriculture could offset up to 1.6% of the fossil fuel emissions in the state.     

Population viability and harvest sustainability for Madagascar lemurs

Subsistence hunting presents a conservation challenge by which biodiversity preservation must be balanced with safeguarding of human livelihoods. Globally, subsistence hunting threatens primate populations, including Madagascar's endemic lemurs. We used population viability analysis to assess the sustainability of lemur hunting in Makira Natural Park, Madagascar. We identified trends in seasonal hunting of 11 Makira lemur species from household interview data, estimated local lemur densities in populations adjacent to focal villages via transect surveys, and quantified extinction vulnerability for these populations based on species-specific demographic parameters and empirically derived hunting rates. We compared stage-based Lefkovitch with periodic Leslie matrices to evaluate the impact of regional dispersal on persistence trajectories and explored the consequences of perturbations to the timing of peak hunting relative to the lemur birth pulse, under assumptions of density-dependent reproductive compensation. Lemur hunting peaked during the fruit-abundant wet season (March–June). Estimated local lemur densities were roughly inverse to body size across our study area. Life-history modeling indicated that hunting most severely threatened the species with the largest bodies (i.e., Hapalemur occidentalis, Avahi laniger, Daubentonia madagascariensis, and Indri indi), characterized by late-age reproductive onsets and long interbirth intervals. In model simulations, lemur dispersal within a regional metapopulation buffered extinction threats when a majority of local sites supported growth rates above the replacement level but drove regional extirpations when most local sites were overharvested. Hunt simulations were most detrimental when timed to overlap lemur births (a reality for D. madagascariensis and I. indri). In sum, Makira lemurs were overharvested. Regional extirpations, which may contribute to broad-scale extinctions, will be likely if current hunting rates persist. Cessation of anthropogenic lemur harvest is a conservation priority, and development programs are needed to help communities switch from wildlife consumption to domestic protein alternatives.     

Factors affecting conviction rates of intoxicated driver patients in two large trauma centers

Objective: Outcomes from previous studies report the driving under the influence (DUI) conviction rates for trauma patients in several cities within Canada and the United States over the last 2 decades. This study reports charge, conviction, and prosecution rates for trauma patients at 2 level I trauma centers servicing a large metropolitan city.

Methods: A retrospective review of the trauma databases was completed to identify patients meeting inclusion criteria. Four hundred sixty patients were identified and their records were compared with the district attorney's records for DUI charges and convictions.

Results: The conviction rate for this study was 8.7%, demonstrating continued low rates of conviction despite growing interest and public awareness of drinking and driving.

Conclusions: We discuss legal considerations that providers should consider when treating patients who have been drinking and driving.     

The farmer as a landscape steward: Comparing local understandings of landscape stewardship,landscape values,and land management actions

We develop a landscape stewardship classification which distinguishes between farmers’ understanding of landscape stewardship, their landscape values, and land management actions. Forty semi-structured interviews were conducted with small-holder (<5 acres), medium-holders (5–100 acres), and large-holders (>100 acres) in South-West Devon, UK. Thematic analysis revealed four types of stewardship understandings: (1) an environmental frame which emphasized the farmers’ role in conserving or restoring wildlife; (2) a primary production frame which emphasized the farmers’ role in taking care of primary production assets; (3) a holistic frame focusing on farmers’ role as a conservationist, primary producer, and manager of a range of landscape values, and; (4) an instrumental frame focusing on the financial benefits associated with compliance with agri-environmental schemes. We compare the landscape values and land management actions that emerged across stewardship types, and discuss the global implications of the landscape stewardship classification for the engagement of farmers in landscape management.     

Increasing polybrominated diphenyl ether (PBDE) contamination in sediment cores from the inner Clyde Estuary,UK

The concentrations of 16 polybrominated diphenyl ether (PBDE) congeners in six short sediment cores from the Clyde Estuary were determined by gas-chromatography mass-spectrometry. Total PBDE concentrations ranged from 1 to 2,645 μg/kg and the average concentration was 287 μg/kg. BDE-209 was the main congener and varied from 1 to 2,337 μg/kg. Elevated total PBDE concentrations were observed close to the sediment surface in the uppermost 10 cm of four of the six sediment cores. Comparison of the down core PBDE profiles revealed that the increase was driven by the accumulation of deca-BDE. Although the deca-BDE mix was dominant, the presence of lower molecular weight congeners BDE-47, BDE-99, BDE-183 and BDE-153 at most sediment intervals suggested additional sources of penta-BDE and octa-BDE pollution. Changing PBDE source input was the major factor in influencing the proportion of nona-brominated congeners, although other explanations such as post burial photo-debromination of BDE-209 cannot be entirely discounted. A clear cascading to lower hepta-, hexa-, and penta-homologues was not found. The increase in total PBDE concentrations and particularly the deca-BDE may possibly be ascribed to the use and subsequent disposal of electrical appliances such as televisions and computers. In the Clyde sediments, the proportion of nona-brominated congeners was higher than that reported for commercial mixtures. This might be due to changing sources of PBDEs or post burial photo-debromination of BDE-209.     

A global assessment of chromium pollution using sperm whales (Physeter macrocephalus) as an indicator species

Chromium (Cr) is a well-known human carcinogen and a potential reproductive toxicant, but its contribution to ocean pollution is poorly understood. The aim of this study was to provide a global baseline for Cr as a marine pollutant using the sperm whale (Physeter macrocephalus) as an indicator species. Biopsies were collected from free-ranging whales around the globe during the voyage of the research vessel The Odyssey. Total Cr levels were measured in 361 sperm whales collected from 16 regions around the globe detectable levels ranged from 0.9 to 122.6 μg Cr g tissue⁻¹ with a global mean of 8.8 ± 0.9 μg g⁻¹. Two whales had undetectable levels. The highest levels were found in sperm whales sampled in the waters near the Islands of Kiribati in the Pacific (mean = 44.3 ± 14.4) and the Seychelles in the Indian Ocean (mean = 19.5 ± 5.4 μg g⁻¹). The lowest mean levels were found in whales near the Canary Islands (mean = 3.7 ± 0.8 μg g⁻¹) and off of the coast of Sri Lanka (mean = 3.3 ± 0.4 μg g⁻¹). The global mean Cr level in whale skin was 28-times higher than mean Cr skin levels in humans without occupational exposure. The whale levels were more similar to levels only observed previously in human lung tissue from workers who died of Cr-induced lung cancer. We conclude that Cr pollution in the marine environment is significant and that further study is urgently needed.