Simultaneous determination of 2-phenylbenzotriazole-type mutagens, PBTA-1 through -8, in river water by liquid chromatography-tandem mass spectrometry

We describe a method for the simultaneous determination of eight kinds of phenylbenzotriazole-type mutagens (PBTA-1, -2, -3, -4, -5, -6, -7 and -8) in river water based on liquid chromatography-tandem mass spectrometry (LC/MS/MS). The application of dopant-assisted atmospheric pressure photoionization (APPI) for the detection of the PBTAs was studied. The APPI technique provided higher PBTA signal intensities than those obtained with an electrospray ionization (ESI) source, and the APPI method was used for the determination of the PBTAs. A solid-phase extraction procedure was used for the extractions of PBTA-1 through -8 from river water. The procedure was rapid and the relative standard deviations were below 15%. The detection limits of PBTA-1 through -8 in river water using the proposed method were found to range from 0.04 to 0.5 ng L(-1) and PBTAs were successfully detected in river water at sub-ng L(-1) levels.     

The Fish Fauna of the Doubs River Prior to Completion of the Rhine–Rhône Connection

/ The part of the Doubs River between Montbeliard and Dole (France), i.e., downstream from the confluence with the Allan River, will be affected by the Rhine- Rhone connection project. In order to improve the understanding of the Doubs ichthyofauna, aquatic environments of the Doubs were sampled by electrofishing. Fish diversity and the presence of some rheophilic species demonstrated the good ecological quality of some stretches of the Doubs. This quality was due to alternating areas with very diversified aquatic environments (riffles, islands and side-arms, backwaters) and a considerable range of flow velocities. The differences in the structure of the fish communities of the different types of aquatic environments were more qualitative (fish species) than quantitative (number of species and number of fish). However, the mean number of fish was statistically lower in the canals (Freycinet canal and channelized part of the Allan River) than in the main course and in the backwaters. The natural parts of the Doubs (unnavigable reaches) showed the most diversified environmental structure and had the most rheophilic fish communities. Thus, the rheophilic species were well represented, but they proved also the most vulnerable to river regulation. However, the most abundant fishes throughout the Doubs River were generalists with no special requirements for food sources or spawning substrate.KEY WORDS: Fish communities; Regulation; Restoration; Floodplain; Large ship canal; Doubs River     

Crisis or opportunity? Economic degrowth for social equity and ecological sustainability. Introduction to this special issue

This article reviews the burgeoning emerging literature on sustainable degrowth. This is defined as an equitable downscaling of production and consumption that increases human well-being and enhances ecological conditions at the local and global level, in the short and long term. The paradigmatic propositions of degrowth are that economic growth is not sustainable and that human progress without economic growth is possible. Degrowth proponents come from diverse origins. Some are critics of market globalization, new technologies or the imposition of western models of development in the rest of the world. All criticize GDP accounting though they propose often different social and ecological indicators. Degrowth theorists and practitioners support an extension of human relations instead of market relations, demand a deepening of democracy, defend ecosystems, and propose a more equal distribution of wealth. We distinguish between depression, i.e. unplanned degrowth within a growth regime, and sustainable degrowth, a voluntary, smooth and equitable transition to a regime of lower production and consumption. The question we ask is how positive would degrowth be if instead of being imposed by an economic crisis, it would actually be a democratic collective decision, a project with the ambition of getting closer to ecological sustainability and socio-environmental justice worldwide.Most articles in this issue were originally presented at the April 2008 conference in Paris on Economic Degrowth for Ecological Sustainability and Social Equity. This conference brought the word degrowth and the concepts around it into an international academic setting. Articles of this special issue are summarized in this introductory article. Hueting, d'Alessandro and colleagues, van den Bergh, Kerschner, Spangenberg and Alcott discuss whether current growth patterns are (un)sustainable and offer different perspectives on what degrowth might mean, and whether and under what conditions it might be desirable. Matthey and Hamilton focus on social dynamics and the obstacles and opportunities for voluntary social action towards degrowth. Lietaert and Cattaneo with Gavaldà offer a down-to-earth empirical discussion of two practical living experiments: cohousing and squats, highlighting the obstacles for scaling up such alternatives. Finally van Griethuysen explains why growth is an imperative in modern market economies, raising also the question whether degrowth is possible without radical institutional changes.     

Fine-scale observations of the predatory behaviour of the carnivorous copepod <Emphasis Type="Italic">Paraeuchaeta norvegica</Emphasis> and the escape responses of their ichthyoplankton prey,Atlantic cod (<Emphasis Type="Italic">Gadus morhua</Emphasis>)

Paraeuchaeta norvegica (8.5 mm total length) and yolk-sac stage Atlantic cod larvae (4 mm total length) (Gadus morhua) larvae were observed in aquaria (3 l of water) using silhouette video photography. This allowed direct observations (and quantitative measurement) of predator–prey interactions between these two species in 3-dimensions. Tail beats, used by cod larvae to propel themselves through the viscous fluid environment, also generate signals detectable by mechanoreceptive copepod predators. When the prey is close enough for detection and successful capture (approximately half a body-length), the copepod launches an extremely rapid high Reynolds number attack, grabbing the larva around its midsection. While capture itself takes place in milliseconds, minutes are required to subdue and completely ingest a cod larva. The behavioural observations are used to estimate the hydrodynamic signal strength of the cod larva’s tail beats and the copepod’s perceptive field for larval fish prey. Cod larvae are more sensitive to fluid velocity than P. norvegica and also appear capable of distinguishing between the signal generated by a swimming and an attacking copepod. However, the copepod can lunge at much faster velocities than a yolk-sac cod larva can escape, leading to the larva’s capture. These observations can serve as input to the predator–prey component of ecosystem models intended to assess the impact of P. norvegica on cod larvae.     

Neural Network Input Selection for Hydrological Forecasting Affected by Snowmelt1

Abstract: Snowmelt largely affects runoff in watersheds in Nordic countries. Neural networks (NN) are particularly attractive for streamflow forecasting whereas they rely at least on daily streamflow and precipitation observations. The selection of pertinent model inputs is a major concern in NNs implementation. This study investigates performance of auxiliary NN inputs that allow short‐term streamflow forecasting without resorting to a deterministic snowmelt routine. A case study is presented for the Rivière des Anglais watershed (700 km²) located in Southern Québec, Canada. Streamflow (Q), precipitations (rain R and snow S, or total P), temperature (T) and snow lying (A) observations, combined with climatic and snowmelt proxy data, including snowmelt flow (Q_SM) obtained from a deterministic model, were tested. NN implemented with antecedent Q and R produced the largest gains in performance. Introducing increments of A and T to the NNs further improved the performance. Long‐term averages, seasonal data, and Q_SM failed to improve the networks.