Monitoring saltwater intrusion in Rupert Bay,Québec,Canada, after the partial diversion of a major tributary

As part of a large hydroelectric project in northern Québec (Canada), a portion of the flow of the Rupert River was diverted toward the existing La Grande hydroelectric complex. As a result of the partial diversion, the discharge of the Rupert River at its mouth is reduced by an average of 50% annually. This corresponds to an 18% decrease in the total freshwater inflow into the bay and, thus, to a shift of the upstream limit of the saltwater intrusion in Rupert Bay. Changes in saltwater intrusion had been predicted numerically as part of the project’s environmental impact assessment (EIA). In the project’s conditions of authorization, monitoring the hydraulic conditions and the extent of saltwater intrusion in the Rupert Bay was required by government authorities. The objective of this paper is to present the results of this environmental monitoring and, more specifically, to validate the modifications predicted in the EIA in terms of both saltwater intrusion limit and hydraulic conditions in the Rupert Bay. Results obtained during 2 years of monitoring are within the predicted trends and order of magnitude of changes anticipated in the EIA. The results, thus, confirm that the shift of the upstream limit of the saltwater front along the channels of the bay was conservatively predicted by numerical modeling.     

A multi-process phytoremediation system for removal of polycyclic aromatic hydrocarbons from contaminated soils

To improve phytoremediation processes, multiple techniques that comprise different aspects of contaminant removal from soils have been combined. Using creosote as a test contaminant, a multi-process phytoremediation system composed of physical (volatilization), photochemical (photooxidation) and microbial remediation, and phytoremediation (plant-assisted remediation) processes was developed. The techniques applied to realize these processes were land-farming (aeration and light exposure), introduction of contaminant degrading bacteria, plant growth promoting rhizobacteria (PGPR), and plant growth of contaminant-tolerant tall fescue (Festuca arundinacea). Over a 4-month period, the average efficiency of removal of 16 priority PAHs by the multi-process remediation system was twice that of land-farming, 50% more than bioremediation alone, and 45% more than phytoremediation by itself. Importantly, the multi-process system was capable of removing most of the highly hydrophobic, soil-bound PAHs from soil. The key elements for successful phytoremediation were the use of plant species that have the ability to proliferate in the presence of high levels of contaminants and strains of PGPR that increase plant tolerance to contaminants and accelerate plant growth in heavily contaminated soils. The synergistic use of these approaches resulted in rapid and massive biomass accumulation of plant tissue in contaminated soil, putatively providing more active metabolic processes, leading to more rapid and more complete removal of PAHs.     

Crinoid phylogeny: a preliminary analysis (Echinodermata: Crinoidea)

We describe the first molecular and morphological analysis of extant crinoid high-level inter-relationships. Nuclear and mitochondrial gene sequences and a cladistically coded matrix of 30 morphological characters are presented, and analysed by phylogenetic methods. The molecular data were compiled from concatenated nuclear-encoded 18S rDNA, internal transcribed spacer 1, 5.8S rDNA, and internal transcribed spacer 2, together with part of mitochondrial 16S rDNA, and comprised 3,593 sites, of which 313 were parsimony-informative. The molecular and morphological analyses include data from the bourgueticrinid Bathycrinus; the antedonid comatulids Dorometra and Florometra; the cyrtocrinids Cyathidium, Gymnocrinus, and Holopus; the isocrinids Endoxocrinus, and two species of Metacrinus; as well as from Guillecrinus and Caledonicrinus, whose ordinal relationships are uncertain, together with morphological data from Proisocrinus. Because the molecular data include indel-rich regions, special attention was given to alignment procedure, and it was found that relatively low, gene-specific, gap penalties gave alignments from which congruent phylogenetic information was obtained from both well-aligned, indel-poor and potentially misaligned, indel-rich regions. The different sequence data partitions also gave essentially congruent results. The overall direction of evolution in the gene trees remains uncertain: an asteroid outgroup places the root on the branch adjacent to the slowly evolving isocrinids (consistent with palaeontological order of first appearances), but maximum likelihood analysis with a molecular clock places it elsewhere. Despite lineage-specific rate differences, the clock model was not excluded by a likelihood ratio test. Morphological analyses were unrooted. All analyses identified three clades, two of them generally well-supported. One well-supported clade (BCG) unites Bathycrinus and Guillecrinus with the representative (chimaeric) comatulid in a derived position, suggesting that comatulids originated from a sessile, stalked ancestor. In this connection it is noted that because the comatulid centrodorsal ossicle originates ontogenetically from the column, it is not strictly correct to describe comatulids as unstalked crinoids. A second, uniformly well-supported clade contains members of the Isocrinida, while the third clade contains Gymnocrinus, a well-established member of the Cyrtocrinida, together with the problematic taxon Caledonicrinus, currently classified as a bourgueticrinid. Another cyrtocrinid, Holopus, joins this clade with only weak molecular, but strong morphological support. In one morphological analysis Proisocrinus is weakly attached to the isocrinid clade. Only an unusual, divergent 18S rDNA sequence was obtained from the morphologically strange cyrtocrinid Cyathidium. Although not analysed in detail, features of this sequence suggested that it may be a PCR artefact, so that the apparently basal position of this taxon requires confirmation. If not an artefact, Cyathidium either diverged from the crinoid stem much earlier than has been recognised hitherto (i.e., it may be a Palaeozoic relic), or it has an atypically high rate of molecular evolution.Electronic Supplementary Material Supplementary material is available in the online version of this article at Communicated by J.P. Thorpe, Port Erin     

Drought can offset potential water use efficiency of forest ecosystems from rising atmospheric CO2

Increasing atmospheric CO₂ is both leading to climate change and providing a potential fertilisation effect on plant growth. However, southern Australia has also experienced a significant decline in rainfall over the last 30 years, resulting in increased vegetative water stress. To better understand the dynamics and responses of Australian forest ecosystems to drought and elevated CO₂, the magnitude and trend in water use efficiency (WUE) of forests, and their response to drought and elevated CO₂ from 1982 to 2014 were analysed, using the best available model estimates constrained by observed fluxes from simulations with fixed and time-varying CO₂. The ratio of gross primary productivity (GPP) to evapotranspiration (ET) (WUEe) was used to identify the ecosystem scale WUE, while the ratio of GPP to transpiration (Tr) (WUEc) was used as a measure of canopy scale WUE. WUE increased significantly in northern Australia (p < 0.001) for woody savannas (WSA), whereas there was a slight decline in the WUE of evergreen broadleaf forests (EBF) in the southeast and southwest of Australia. The lag of WUEc to drought was consistent and relatively short and stable between biomes (≤3 months), but notably varied for WUEe, with a long time-lag (mean of 10 months). The dissimilar responses of WUEe and WUEc to climate change for different geographical areas result from the different proportion of Tr in ET. CO₂ fertilization and a wetter climate enhanced WUE in northern Australia, whereas drought offset the CO₂ fertilization effect in southern Australia.     

A Method for Improving the Management of Controversial Wetland

Valley bottom wetlands in agricultural landscapes often are neglected in national and regional wetland inventories. Although these areas are small, located in the bottomlands of the headwater catchments, and scattered in the rural landscape, they strongly influence hydrology, water quality, and biodiversity over the whole catchment area. Valley bottom wetlands often are considered as controversial wetlands. Awareness of the functional role of wetlands is increasing, in parallel with their progressive disappearance in intensive farming landscapes. The need to improve tools for controlling wetland management is a primary consideration for decision makers and land users. This article proposes a method for the inventory of valley bottom wetlands. The method is based on the functional analysis of potential, existing, and efficient valley bottom wetlands (the PEEW approach). Several indicators are proposed for checking the validity of such an approach. Potential wetlands are delineated by means of a topographic index using topographic and pedoclimatic criteria computed from a Digital Elevation Model and easily accessible databases. Existing wetlands are identified from observed surface moisture, the presence of specific wetland vegetation, or soil feature criteria. Efficient wetlands are defined through a given function, such as flow or pollutant regulation or biodiversity control. An analysis of areas at the limits between potential, existing, and efficient wetlands highlights land cultivated or drained in the past, which currently represents negotiating areas in which rehabilitation and other intended management actions can be implemented.     

A development in energy flow/barrier analysis

In this paper, the occupational accidents and their effects on people are modeled. The basis of energy flow/barrier analysis is used to define an accident as the impact of a hazardous agent on a target, as a result of failure of control and protective barriers. This definition is enhanced to include serial and parallel barriers and to distinguish energy barriers from target barriers. The barrier attributes are defined and used to create a quantitative scenario-building model. The probability and severity of various accidents are estimated, by studying barrier reliability and efficiency. This approach is used to develop and simulate accident scenarios and to calculate their consequences. This model can be used in complex systems for analyzing the risk and estimating the importance of barriers.     

Using social resilience and resource dependency to increase the effectiveness of marine conservation initiatives in Salum,Egypt

The social and economic ramifications of marine conservation strategies such as marine protected areas (MPAs) are important to consider prior to their implementation to ensure that they do not exceed the resilience of resource-users and that resource protection might be maximised through compliance and low resistance. This paper presents a framework in which the human dimensions can be more easily and usefully integrated into the design and delivery of conservation initiatives. The framework espouses quantifying (1) the level of dependency on the resource; (2) perceptions towards conservation initiatives; and (3) social resilience. The framework is applied in Salum, Egypt, which is the site of a prospective MPA.     

Survival of the cleanest? Evidence from a plant-level analysis of pollutant emissions in Canadian pulp and paper industry, 2005–2013

Environmental Economics and Policy Studies - We capitalize on access to plant-level data in examining the changes in emissions of biochemical oxygen demand (BOD), total suspended solids (TSS), and...