Motile cryptofauna associated with live and dead coral substrates: implications for coral mortality and framework erosion

Coral reef cryptofauna are a diverse group of metazoan taxa that live within intra- and inter-skeletal voids formed by framework structures. Despite a hypothesized high biomass and numerous trophic roles, they remain uncharacterized relative to exposed reef communities. Motile cryptofauna were sampled from live coral colonies and dead frameworks typifying four successive levels of degradation on an eastern Pacific pocilloporid reef. Abundances and biomass were higher on live versus dead corals habitats. The density of cryptofauna per volume substrate was highest on dead coral frameworks of intermediate degradation, where complex eroded substrates provide abundant shelters. These data have important and far-reaching ramifications for how the diverse multispecies assemblages that are reef ecosystems will respond to anthropogenic stressors such as those associated with climate change. Extreme levels of coral mortality, bioerosion, and habitat destruction will lead to impairment and eventually loss of ecosystem functions.     

The effects of climate change on landscape diversity: an example in Ontario forests

The predicted increase in climate warming will have profound impacts on forest ecosystems and landscapes in Canada because of increased temperature, and altered disturbance regimes. Climate change is predicted to be variable within Canada, and to cause considerable weather variability among years. Under a 2 × CO₂ scenario, fire weather index (FWI) is predicted to rise over much of Ontario by 1.5 to 2 times. FWI may actually fall slightly, compared to current values, in central eastern Ontario (Abitibi), but for central-south Ontario it is expected to rise sharply by as much as 5 times current values. We predict that the combination of temperature rise and greater than average fire occurrence will result in a shrinkage of area covered by boreal forest towards the north and east; that some form of Great Lakes forest type will occupy most of central Ontario following the 5 C isotherm north; that pyrophilic species will become most common, especially jack pine and aspen; that patch sizes will initially decrease then expand resulting in considerable homogenization of forest landscapes; that there will be little 'old-growth' forest; and that landscape disequilibrium will be enhanced. If climate change occurs as rapidly as is predicted, then some species particularly those with heavy seeds may not be able to respond to the rapid changes and local extinctions are expected. Anthropogenically-altered species compositions in current forests, coupled with fire suppression over the past 50 years, may lead to forest landscapes that are different then were seen in the Holocene period, as described by paleoecological reconstructions. In particular, forests dominated by white pine in the south and black spruce in the middle north may not be common. Wildlife species that respond at the landscape level, i.e., those with body sizes >1 kg, will be most affected by changes in landscape structure. In particular we expect moose and caribou populations to decline significantly, while white-tailed deer will likely become abundant across Ontario and Quebec.     

Changes in the nature of sewage sludge organic matter during a twenty-one-month incubation

Six sewage sludges from five sewage treatment plants in Australia were incubated for up to 21 months. Carbon losses at the end of the 21-mo incubation varied substantially. The remaining organic matter was isolated by treatment with hydrofluoric acid (HF) and characterized using a range of solid-state (13)C nuclear magnetic resonance (NMR) spectroscopic techniques. By every measure (signal distribution in cross polarization [CP] and Bloch decay [BD] spectra, carbon NMR observability determined by spin counting, and the appearance of proton spin relaxation editing subspectra), the chemical composition of the residual organic matter appeared to be little different from that of the original sludges, even for those sludges that experienced the greatest carbon losses. Importantly, these NMR properties distinguish sewage sludge organic matter from soil organic matter. Thus, it should be possible to follow the decomposition of sewage sludge organic matter applied to soils in the field using solid-state (13)C NMR spectroscopy.     

Biodegradability of a Selected Range of Polymers and Polymer Blends and Standard Methods for Assessment of Biodegradation

Synthetic polymers are important to the packaging industry but their use raises aesthetic and environmental concerns, particularly with regard to solid waste accumulation problems and the threat to wildlife. Some concerns are addressed by attention to problems associated with source reduction, incineration, recycling and landfill. Others are addressed by the development of new biodegradable polymers either alone or in blends. Materials used for biodegradable polymers include various forms of starch and products derived from it, biopolyesters and some synthetic polymers. Starch is rapidly metabolised and is an excellent base material for polymer blends or for infill of more environmentally inert polymers where it is metabolised to leave less residual polymer on biodegradation. This should help to improve the environmental impact of waste disposal. A number of standard methods have been developed to estimate the extent of biodegradability of polymers under various conditions and with a variety of organisms. They tend to be used mainly in the countries where they were developed but there is much overlap between the standards of different countries and wide scope for development of consistent and international standards.     

City Partners Maintain Climate Change Action Despite National Cuts: Residential Energy Efficiency Programme Valued at Local Level

Cities, regional governments and their local utilities are taking leading roles in programmes to reduce greenhouse gas emissions. Agenda 21 highlighted the need for such local action to achieve the goals of the 1992 Earth Summit and the United Nations Framework Convention on Climate Change. This trend of increasing local action was demonstrated dramatically in Canada in 2006 when the newly elected federal government cancelled many of the previous government's climate change programmes. The EnerGuide for Houses Program illustrates the growing importance of local decisions where the federal government developed a home energy rating system that was delivered through a range of partnerships across the country. Despite all political parties voting to increase funding for the programme in 2005, the Conservative government cancelled it in May 2006. The response by provincial and local governments was immediate. Their actions revealed the ability and desire among lower-tier governments to sustain popular climate change initiatives. Both the political responses and financial implications are included in the examination of the shift in environmental responsibility from the national to the local sphere.     

FORECASTING QUARTER-MONTHLY RIVERFLOW1

Recent developments with respect to transfer function-noise models are reviewed and used to model and forecast quarter-monthly (i.e., near-weekly) natural inflows to the Lac St-Jean reservoir in the Province of Quebec, Canada. The covariate series are rainfall and snowmelt, the latter being a novel derivation from daily rainfall, snowfall and temperature series. It is clearly demonstrated using the residual variance and the Akaike information criterion that modeling is improved as one starts with a deseasonalized ARMA model of the inflow series and successively adds transfer functions for the rainfall and snowmelt series. It is further demonstrated that the transfer function-noise model is better than a periodic autoregressive model of the inflow series. A split-sample experiment is used to compare one-step-ahead forecasts from this transfer function-noise model with forecasts from other stochastic models as well as with forecasts from a so-called conceptual hydrological model (i.e., a model which attempts to mathematically simulate the physical processes involved in the hydrological cycle). It is concluded that the transfer function-noise model is the preferred model for forecasting the quarter-monthly Lac St-Jean inflow series.     

Characterization of sewage sludge organic matter using solid-state carbon-13 nuclear magnetic resonance spectroscopy

Six sewage sludges from five sewage treatment plants in Australia were characterized using solid-state 13C nuclear magnetic resonance (NMR) spectroscopy. Spectra were acquired both before and after removal of mineral components through treatment with hydrofluoric acid (HF). Carbon mass balance indicated that little organic matter was lost on HF treatment, which significantly improved NMR sensitivity and spectral resolution, and decreased acquisition time and hence cost of NMR analysis. Two NMR techniques were used, the standard cross polarization (CP) technique and Bloch decay (BD). The BD technique had not been applied previously to the analysis of sewage sludge. For each sludge sample, both before and after HF treatment, the BD spectrum contained significantly more alkyl carbon. Spin counting, another technique applied to sewage sludge here for the first time, showed that the BD spectra of the HF-treated sludges were quantitative, while approximately 30% of the CP NMR signal went undetected. The discrepancy between CP and BD spectra was attributed to the presence of alkyl carbon with such high molecular mobility that the efficiency of cross polarization is affected. This study shows that sewage sludge organic matter is significantly different in chemistry to soil organic matter and has implications for the application of sewage sludge to agricultural land.     

Temperature and developmental plasticity during embryogenesis in the Atlantic cod<Emphasis Type="Italic"> Gadus morhua</Emphasis> L.

Atlantic cod (Gadus morhua L.) embryos were reared at 4 °C, 7 °C, and 10 °C, and the relative timing of developmental events was characterized, with particular reference to myotomal muscle. Embryos started to feed at an apparently equivalent stage of development, so comparisons were made between temperature groups on the basis of percentage of time to first feeding and somite stage. No differences were found in the time of hatching or timing of appearance of the otic placode, unpaired median fin fold, gut lumen, otic vesicle, lens of the eye, otoliths, first muscular contractions, swim bladder, and hindgut, or in the rate of development of somites, myotubes, myofibrils, and acetylcholinesterase activity over the temperature range studied. In contrast, closure of the blastopore occurred late with respect to segmentation at higher temperatures, at the 3-somite, 10-somite, and 12-somite stages at 4 °C, 7 °C, and 10 °C respectively. Muscle cellularity was also markedly altered in the 10 °C group relative to the 4 °C and 7 °C groups. Larvae reared at 10 °C had significantly more (+14%) deep white fibers at hatch (P <0.001), whereas numbers of superficial red fibers remained unchanged. It is suggested that differences in muscle cellularity might be related to changes in the relative timing of epiboly, through differential proliferation of presomitic myogenic cells and/or their relative exposure to inductive signals.     

Uptake and effects of the cypermethrin-containing sea lice treatment Excis in the marine mussel,Mytilus edulis

Wild and farmed mussels, Mytilus edulis, coexist with salmon farms in Scottish sea lochs. A synthetic pyrethroid, cypermethrin, is licensed for use on fish farms to control sea lice infestations as a formulation called Excis. In this study, uptake of cypermethrin from Excis exposure is investigated through the use of gas chromatography with mass-spectrometry. The effects of Excis on mussels are also examined by measuring the neutral red retention time of lysosomes, aerial survival and shell closure. The isomeric ratios of cis:trans cypermethrin measured in mussels are around 80:20; a marked increase from 40:60 to which the mussels were exposed. This is most likely due to preferential metabolism of trans-isomers, as the same response is seen in vertebrates. There is a pronounced behavioural effect of shell closure, where mussels exposed to 1000 microg/l cypermethrin shut their shells within an hour of exposure. Arguments are presented for this effect being either a voluntary response on recognition of cypermethrin, or an effect arising from an involuntary action of cypermethrin on the adductor muscle. Even at 1000 microg/l cypermethrin, neutral red retention time and aerial survival are not affected. The data suggest that the responses of mussels shown here are unlikely to occur in the field, even at the concentrations of cypermethrin used in fish cages, for the treatment of sea lice.