Offspring sex ratio in relation to female size in southern elephant seals,Mirounga leonina

Southern elephant seals Mirounga leonina display extreme sexual dimorphism. In addition females show great variation in size and stored resources at parturition. Therefore they present an excellent opportunity for examination of responses of sex ratio to resource availability. We studied the relationships between the size of southern elephant seal females at parturition and the size and sex of their pups at South Georgia over four breeding seasons. We found a large individual variation in maternal post-partum mass (range 296–977 kg, n=151). Larger mothers gave birth to larger pups, irrespective of the sex of their pup. Male pups were on average 14% larger than females at birth and consequently more costly to bring to parturition. Our results suggest that female southern elephant seals must weigh more than 300 kg if they are to breed at all, and more than 380 kg if they are to give birth to a male pup. Above this threshold the proportion of males among offspring rapidly increases with maternal mass, and stabilizes at a level not significantly different from parity. These results show that smaller females of southern elephant seals vary offspring sex ratio in a way that is consistent with theories on adaptive offspring sex ratio. A smaller mother with a male foetus may benefit from terminating her pregnancy and allocating the resources she saves to her own growth. She could then give birth to and raise a larger pup in the subsequent season.     

Advanced geophysical underground coal gasification monitoring

Underground Coal Gasification (UCG) produces less surface impact, atmospheric pollutants and greenhouse gas than traditional surface mining and combustion. Therefore, it may be useful in mitigating global change caused by anthropogenic activities. Careful monitoring of the UCG process is essential in minimizing environmental impact. Here we first summarize monitoring methods that have been used in previous UCG field trials. We then discuss in more detail a number of promising advanced geophysical techniques. These methods – seismic, electromagnetic, and remote sensing techniques – may provide improved and cost-effective ways to image both the subsurface cavity growth and surface subsidence effects. Active and passive seismic data have the promise to monitor the burn front, cavity growth, and observe cavity collapse events. Electrical resistance tomography (ERT) produces near real time tomographic images autonomously, monitors the burn front and images the cavity using low-cost sensors, typically running within boreholes. Interferometric synthetic aperture radar (InSAR) is a remote sensing technique that has the capability to monitor surface subsidence over the wide area of a commercial-scale UCG operation at a low cost. It may be possible to infer cavity geometry from InSAR (or other surface topography) data using geomechanical modeling. The expected signals from these monitoring methods are described along with interpretive modeling for typical UCG cavities. They are illustrated using field results from UCG trials and other relevant subsurface operations.     

Interrelationship of age and diet in Romania’s oldest human burial

In 1968, excavations in the Climente II cave in the Iron Gates gorge of the River Danube in southwest Romania unearthed the skeleton of an adult male. The burial was assumed to be of Late Pleistocene age because of the presence of Late Upper Palaeolithic (LUP) artefacts in the cave. However, there was no strong supporting stratigraphic evidence, and the body position is reminiscent of Early Neolithic burial practice in the region. Here, we report the results of radiocarbon and stable isotope analyses of the Climente II skeleton, which show that the skeleton dates to the Bølling–Allerød Interstadial ~14,500 cal BP. This is several millennia older than any previously dated human remains from the Iron Gates region and confirms its status as the oldest known burial from Romania. The stable isotope results indicate a diet with an emphasis on aquatic resources, contrary to the commonly held view that the LUP inhabitants of the Iron Gates subsisted mainly by hunting large land mammals.     

Substrate-dependent bacterivory by intertidal benthic copepods

The trophic importance of bacteria to harpacticoid copepods in intertidal areas remains poorly understood, and so do the mechanisms of bacterial feeding. It is, for instance, unclear whether harpacticoids directly target bacterial cells or merely co-ingest them with substrates to which bacterial cells may be attached. Here, we investigate bacterial uptake and substrate requirement for four mud intertidal species (Microarthridion littorale, Platychelipus littoralis, Delavalia palustris and Nannopus palustris) by means of ¹³C-labeled bacteria and biomarker fatty acids (FA). Bacterial uptake strongly depended on grazing on a primary food source but bacterial ingestion rates were low, and no clear indication of copepods directly targeting bacteria was found. Delavalia was the only species that accumulated bacteria-derived FA and gained in polyunsaturated FA (PUFA) probably through bioconversion of bacteria-derived FA. In general, however, our results suggest that bacteria represent a relatively minor and low-quality food for intertidal harpacticoid copepods.     

Conserving Mangrove Ecosystems in the Philippines: Transcending Disciplinary and Institutional Borders

Humans are rapidly depleting critical ecosystems and the life support functions they provide, increasing the urgency of developing effective conservation tools. Using a case study of the conversion of mangrove ecosystems to shrimp aquaculture, this article describes an effort to develop a transdisciplinary, transinstitutional approach to conservation that simultaneously trains future generations of environmental problem solvers. We worked in close collaboration with academics, non-government organizations, local government and local communities to organize a workshop in Puerto Princesa, Palawan, Philippines. The primary objectives of the workshop were to: (1) train participants in the basic principles of ecological economics and its goals of sustainable scale, just distribution and efficient allocation; (2) learn from local community stakeholders and participating scientists about the problems surrounding conversion of mangrove ecosystems to shrimp aquaculture; (3) draw on the skills and knowledge of all participants to develop potential solutions to the problem; and (4) communicate results to those with the power and authority to act on them. We found that the economic and ecological benefits of intact mangroves outweigh the returns to aquaculture. Perversely, however, private property rights to mangrove ecosystems favor inefficient, unjust and unsustainable allocation of the resource—a tragedy of the non-commons. We presented the workshop results to the press and local government, which shut down the aquaculture ponds to conserve the threatened ecosystem. Effective communication to appropriate audiences was essential for transforming research into action. Our approach is promising and can be readily applied to conservation research and advocacy projects worldwide, but should be improved through adaptive management—practitioners must continually build on those elements that work and discard or improve those that fail.     

Air revitalization compounds: A literature survey

Chemical processes for air revitalization are attractive alternatives for some closed life support systems in the applications of space and marine explorations. A review of the literature is given for the purpose of evaluating potential candidates as air revitalizing chemicals based upon a set of criteria including toxicity in use, removal of airborne contaminants and bacteria, theoretical oxygen yields, chemical reactivity to breathing atmospheres, and commercial availability. The preliminary evaluation shows potassium and sodium Superoxides as prime candidates for further evaluation against the practical considerations of actual use. Upon closer scrutiny, potassium Superoxide is the desired chemical for air revitalization in closed life support systems according to the present technology. Kinetic reaction rates for the simple hydration of KO₂ were reported to increase for increasing pressures to 12 atm making it a promising air revitalization chemical at the hyperbaric conditions encountered in deep diving.     

A field trial to assess the performance of CO2-supersaturated water injection for residual volatile LNAPL recovery

A pilot scale field trial was conducted to evaluate the recovery of volatile, light non-aqueous phase liquids (LNAPLs) using a novel remediation method termed supersaturated water injection (SWI). SWI uses a patented technology to efficiently dissolve high concentrations of CO₂ into water at elevated pressures. This water is injected into the subsurface resulting in the nucleation of CO₂ bubbles at and away from the injection point. The nucleating bubbles coalesce, rise and volatilize residual LNAPL ganglia. In this study, an LNAPL composed of 103 kg of volatile pentane and hexane, and 30 kg of non-volatile Soltrol was emplaced below the water table at residual saturation. The SWI technology removed 78% of the pentane and 50% of the less volatile hexane. Contaminant mass was still being removed when the system was shut down for practical reasons. The mass removed is comparable to that expected for air sparging but a much smaller volume of gas was injected using the SWI system.     

Security risks in nuclear waste management: Exceptionalism,opaqueness and vulnerability

This paper analyses some potential security risks, concerning terrorism or more mundane forms of crime, such as fraud, in management of nuclear waste using a PEST scan (of political, economic, social and technical issues) and some insights of criminologists on crime prevention. Nuclear waste arises as spent fuel from ongoing energy generation or other nuclear operations, operational contamination or emissions, and decommissioning of obsolescent facilities. In international and EU political contexts, nuclear waste management is a sensitive issue, regulated specifically as part of the nuclear industry as well as in terms of hazardous waste policies. The industry involves state, commercial and mixed public–private bodies. The social and cultural dimensions – risk, uncertainty, and future generations – resonate more deeply here than in any other aspect of waste management. The paper argues that certain tendencies in regulation of the industry, claimed to be justified on security grounds, are decreasing transparency and veracity of reporting, opening up invisible spaces for management frauds, and in doing allowing a culture of impunity in which more serious criminal or terrorist risks could arise. What is needed is analysis of this ‘exceptional’ industry in terms of the normal cannons of risk assessment – a task that this paper begins.