The ‘Storm of the Century’ (December 1999) and the accidental escape of Siberian sturgeons (Acipenser baerii) into the Gironde estuary (Southwest France)

GOAL, SCOPE AND BACKGROUND: The Gironde estuary is considered as a reference ecosystem with a large fish assemblage (75 species) and the presence of eleven diadromous species. However, geochemical studies and biomonitoring using oysters have shown high metal pollution levels. During the December 1999 hurricane, more than 5,000 young Siberian sturgeons (Acipenser baerii) accidentally escaped from a fish farm into the estuary, where this species had not been present until then. METHODS: In 2002/2003, thirteen sturgeons were collected from the estuary and twelve were obtained from the fish farm, from the same initial batch. Analysis of five metals (cadmium, zinc, copper, lead, mercury) measured in the gills, muscle, liver and kidneys, revealed significantly higher levels of cadmium, lead and mercury in the sturgeon collected from the estuary compared with those from the fish farm. RESULTS AND DISCUSSION: Metal analysis of the stomach contents of fish collected from the estuary and artificial food used in the fish farm indicated that dietary exposure might account for the differences observed. Nevertheless, metal concentrations in sturgeons that had spent about three years in the Gironde estuary may be considered low when compared with other species (mullets, eels) or with data in the literature regarding concentrations able to induce structural and functional perturbations in fish. As the introduced Siberian sturgeons live in the same place and feed on the same prey as the juveniles of the endangered A. sturio, our results indicate in the short-term that this strictly protected species does not appear to be much affected by the polymetallic pollution in the Gironde estuary. Marked differences in the concentrations of three metals (Cd, Pb, Hg) were established in four organs (gills, liver, skeletal muscle, kidneys) of Siberian sturgeons between specimens that had accidentally escaped into the Gironde estuary (France) during the December 1999 hurricane and were collected in March/June 2003 and specimens from the same initial batch at the fish farm. RECOMMENDATIONS AND PERSPECTIVES: Based on these results, a programme will be set up, with sampling campaigns carried out in the estuary every two years, with systematic monitoring of age in order to check the origin of individuals, in conjunction with sampling of sturgeon from the fish farm. This programme will complement other studies on several biological species representative of the main trophic levels in the estuary, especially the plankton component, benthic macroinvertebrates and oysters.     

Preliminary study of ballistic impact on an industrial tank: Projectile velocity decay

Since the events of September 11, 2001, the possibility of an intentional act targeting the chemical process industry has become realistic. It is, therefore, a great concern to be able to predict the immediate consequences of such an act. This study is intended to improve our knowledge about the sequence of events that occurs when a high-speed bullet (>1000 m s⁻¹) penetrates a vessel filled with toxic liquid. We find that, prior to liquid ejection, several well-defined phases occur, including the phenomenon known as the “hydraulic ram.” This paper focuses on projectile–target interactions and explains how the decay of projectile velocity is related to the initial conditions of the target.     

Documentation of the endotoxins present in the ambient air of cotton fiber textile mills in Québec

Cotton workers are recognized as being at risk of developing occupational lung diseases. Some researchers have identified endotoxins as being a potential etiologic agent for some of the respiratory problems. This study wants to document the concentration of endotoxins found in the ambient air of textile mills where cotton fibers are handled and to identify the processing steps where the highest endotoxins concentrations in the air were found and the one where the relative limit values (RLVs) are exceeded. The 4 mills studied process cotton fibers. All the air samples were analyzed using the chromogenic Limulus Amoebocytes lysate LAL method using a kinetic detection principle based on the IRSST's standard method. In this study, a large variability in the concentrations of endotoxins in the air was observed, depending on the mill, the processing step, and the time. Despite these variations, some processes can be identified as being major generators of endotoxins in the ambient air of the mills. The highest concentrations were measured in the weaving and drawing processes and reached 10,000 EU m(-3) of air. The opening, cleaning, carding, spinning and drawing processes are the other major endotoxins generating processes with concentrations from 24 to 8,700 EU m(-3) of air. The endotoxins concentrations exceeded the RLVs for 55% of the workstations in this project. This study demonstrated that endotoxins levels in the cotton industry are high and appropriate control measures are needed.     

Soil nitrous oxide emissions following band-incorporation of fertilizer nitrogen and swine manure

Treatment of liquid swine manure (LSM) offers opportunities to improve manure nutrient management. However, N2O fluxes and cumulative emissions resulting from application of treated LSM are not well documented. Nitrous oxide emissions were monitored following band-incorporation of 100 kg N ha(-1) of either mineral fertilizer, raw LSM, or four pretreated LSMs (anaerobic digestion; anaerobic digestion + flocculation: filtration; decantation) at the four-leaf stage of corn (Zea mays L.). In a clay soil, a larger proportion of applied N was lost as N2O with the mineral fertilizer (average of 6.6%) than with LSMs (3.1-5.0%), whereas in a loam soil, the proportion of applied N lost as N2O was lower with the mineral fertilizer (average of 0.4%) than with LSMs (1.2-2.4%). Emissions were related to soil NO3 intensity in the clay soil, whereas they were related to water-extractable organic C in the loam soil. This suggests that N2O production was N limited in the clay soil and C limited in the loam soil, and would explain the interaction found between N sources and soil type. The large N2O emission coefficients measured in many treatments, and the contradicting responses among N sources depending on soil type, indicate that (i) the Intergovernmental Panel on Climate Change (IPCC) default value (1%) may seriously underestimate N2O emissions from fine-textured soils where fertilizer N and manure are band-incorporated, and (ii) site-specific factors, such as drainage conditions and soil properties (e.g., texture, organic matter content), have a differential influence on emissions depending on N source.     

Development of a standardized in vitro approach to evaluate microphysical, chemical, and toxicological properties of combustion-derived fine and ultrafine particles

Ultrafine particles represent a growing concern in the public health community but their precise role in many illnesses is still unknown. This lack of knowledge is related to the experimental difficulty in linking their biological effects to their multiple properties, which are important determinants of toxicity. Our aim is to propose an interdisciplinary approach to study fine(FP) and ultrafine(UFP) particles, generated in a controlled manner using a mini CAST(Combustion Aerosol Standard) soot ...     

Contrasting direct and indirect effects of warming and drought on isoprenoid emissions from Mediterranean oaks

Regional Environmental Change - The degree to which climate warming and increasing drought will alter isoprenoid emissions of Mediterranean forests remains unclear, because most studies were...     

Drei neue Nickelenzyme aus anaeroben Bakterien

Until recently nickel was not considered to be an element of biological importance. Nutritional studies have shown, however, that many eucaryotic and procaryotic organisms are dependent on the transition metal for growth. Four enzymes are presently known to contain nickel: urease from plants and from bacteria; methyl CoM reductase from methanogenic bacteria; all “uptake” hydrogenases investigated so far; and carbon monoxide dehydrogenase from anaerobic bacteria. The prosthetic group of the methyl CoM reductase has been identified as a nickel tetrapyrrole, the structure of which has been elucidated.     

Fetal toxoplasmosis and negative amniocentesis: necessity of an ultrasound follow-up

Prenatal diagnosis of congenital toxoplasmosis relies on the PCR test on amniotic fluid and ultrasound follow-up of the fetus. We report two cases of toxoplasma infection during the first trimester of gestation with a discrepant diagnosis of fetal infection. PCR performed more than four weeks after the estimated date of contamination was negative. Ultrasound follow-up was normal up to the third trimester when major hydrocephalus was detected, leading to pregnancy termination. In both cases, post-mortem examination revealed a diffuse infection with severe brain lesions. These observations confirm the necessity to continue a monthly ultrasound follow-up, even if amniocentesis is negative, in case of fetal toxoplasma infection in pregnancy. Copyright © 2003 John Wiley & Sons, Ltd.