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Masson S.,SEPAQ | Couillard Y.,Environment Canada | Campbell P.G.C.,University of Québec | Olsen C.,COREM | And 2 more authors.
Journal of Environmental Monitoring | Year: 2010

Specimens of the mayfly larva Hexagenia limbata and of the floater mussel Pyganodon grandis were sampled in rivers and lakes contaminated by trace metals in the Abitibi-James Bay region in northwestern Québec. Water samples were collected at each sampling site with in situ diffusion samplers and analyzed for major cations, anions and trace metals (Cd, Cu, Mn, Zn). Surficial sediment samples were also collected at each site and analyzed for Cd, Cu and Zn. In response to Cd contamination at river and lake sites, both sentinel organisms accumulated the metal and synthesized metallothionein (MT), a metal-binding protein synthesized by organisms as a defence mechanism against excess metals in the surrounding media. At the river sites, H. limbata unexpectedly maintained much higher concentrations of MT per unit of accumulated Cd than at the lake sites; this difference between lentic and lotic environments may reflect the response of the species to the more stressful hydrodynamic conditions that prevail in a river. The accumulation of Cd in the mayflies at lake and river sites decreased as a function of the ambient manganese concentration. We hypothesize that dissolved Mn protects against Cd bioaccumulation in H. limbata. The present results support the contention that one cannot extrapolate conclusions drawn from the use of a single sentinel species to a larger set of freshwater invertebrates - both the mayfly and the bivalve are promising biomonitors. © 2010 The Royal Society of Chemistry.

Bado-Nilles A.,CNRS Environmental Stress and Aquatic Monitoring | Bado-Nilles A.,University of Reims Champagne Ardenne | Villeret M.,CNRS Environmental Stress and Aquatic Monitoring | Villeret M.,University of Le Havre | And 8 more authors.
Marine Pollution Bulletin | Year: 2015

European bullhead is a relevant fish species to assess adverse effects of environmental stress on wild fish. Nevertheless, their complex reproductive cycle is very different between sites and could interfere with many physiological processes. Thus, prior to use biomarker to statute on environmental quality of rivers, we wanted to characterize reproductive profile (spawn number, GSI, gonad development). The major results demonstrated that the two types of reproductive cycle shown were strongly correlated to water temperature variation. In a second time, even if innate immunomarkers are highly relevant on biomonitoring program, hormonal variation seems to impact severely their responses. Thus, the link between reproductive status and immune activity (leucocyte distribution, cellular mortality, respiratory burst, phagocytosis activity) must also be study. Nonetheless, in the present work, immune capacities seems to be more correlated with season and environmental factors than reproduction. © 2015 Elsevier Ltd.

Collas M.,Office National de lEAU et des Milieux Aquatiques ONEMA | Becking T.,CNRS Ecobiological Interactions | Delpy M.,CNRS Ecobiological Interactions | Pflieger M.,Office National de lEAU et des Milieux Aquatiques ONEMA | And 3 more authors.
Knowledge and Management of Aquatic Ecosystems | Year: 2016

A mass mortality was detected in the downstream section of one of the most extensive French populations of the endangered white-clawed crayfish, Austropotamobius pallipes, on June 26, 2013. This population occupied a 12 km stretch of the La Lucelle brook, with an estimated size of around 150 000 individuals. The presence of the crayfish plague pathogen was quickly diagnosed as the cause of the mortality, and monitoring was carried out to follow the spread of the disease from 15 July 2013 for one year. Results showed that after a fast spread between 15 and 25 July 2013 (upstream progression of mortality for about 4 km), the mortality front was limited to a stretch of a few hundred meters from August until December 2013. During winter, mortality was always observed, confirming that disease remained active. In April 2014, the mortality front was halted by a large dam in the brook (2 m high), 0.56 km from brook source. Two months later, 30 live crayfish were observed above the dam. On the 30 August 2014, no crayfish were found above the dam. Infected individuals analysed for microsatellite markers confirmed the Pacifastacus leniusculus strain of Aphanomyces astaci at the origin of this outbreak. Before the crayfish plague spread upstream of the large dam, a sample of 576 individuals was collected from upstream of the dam and translocated to another stream in the same French department. In July 2014, observations by night confirmed the presence of translocated white-clawed crayfish in the receiving brook. © M. Collas et al., published by EDP Sciences, 2016.

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