About
116
Publications
13,365
Reads
How we measure 'reads'
A 'read' is counted each time someone views a publication summary (such as the title, abstract, and list of authors), clicks on a figure, or views or downloads the full-text. Learn more
4,151
Citations
Introduction
Current institution
Publications
Publications (116)
In Northern Canada, pollution from mining discharges represents a significant environmental stressor for aquatic organisms. Variations in water temperature constitute another source of stress for fish. Although numerous studies have investigated the effects of environmental stressors on fish physiology, research specifically addressing their impact...
Temperate freshwater fishes can experience large seasonal temperature fluctuations that could affect their exposure and sensitivity to trace metals. Yet, temperature effects are overlooked in ecotoxicology studies, especially for cold temperatures typical of the winter. In the present study, the effects of long-term cold acclimation on Cd bioaccumu...
Diluted bitumen (dilbit) is an unconventional oil produced by the oil sands industry in Canada Despite the knowledge available on hydrocarbon toxicity, the effects of diluted bitumen on benthic organisms are still largely unknown. Moreover, in Quebec there are only the provisional threshold values of 164 mg/kg C10-C50 for chronic effects and 832 mg...
In this study, we investigated the combined effects of temperature and nickel (Ni) contamination on liver mitochondria electron transport system (ETS) enzymes, citrate synthase (CS), phospholipid fatty acid composition and lipid peroxidation in rainbow trout (Oncorhynchus mykiss). Juvenile trout were acclimated for two weeks to two different temper...
For several decades, Northern Québec has been exploited by mining companies for its mineral resources, yet, research documenting the effects of toxic stress on fish health in subarctic environments remains limited. In this study, one lake directly affected by mining activities in the Schefferville area, two lakes close to mining facilities in the F...
Atlantic salmon is an important species for Canadian culture and economy and its importance extends beyond Canada to Scandinavia and Western Europe. However, it is a vulnerable species facing decline due to habitat contamination and destruction. Existing and new Canadian pipeline projects pose a threat to salmonid habitat. The effects of diluted bi...
The oil sands industry in Canada, produces heavy unconventional oils, diluted for transport and called diluted bitumen. However, despite advances in our knowledge of the ecotoxicological risk that these products represent, their effects on benthic organisms following a spill are still largely unknown. In order to fill these gaps, this study aims to...
Pressures from anthropogenic activities are causing degradation of estuarine and coastal ecosystems around the world. Trace metals are key pollutants that are released and can accumulate in a range of environmental compartments and are ultimately accumulated in exposed biota. The level of pressure varies with locations and the range and intensity o...
Municipal wastewater treatment plant (WWTP) effluents are significant sources of organic and inorganic pollutants to aquatic ecosystems. Several studies have shown that the health of aquatic organisms can be adversely impacted following exposure to these complex chemical mixtures. The objective of this study was to examine the effects of in situ ex...
Ecotoxicological research detailing trace metal contamination and seasonal variation in the tissues of northern fishes such as Arctic charr (Salvelinus alpinus) has been poorly represented in the literature beyond examination of mercury. In an effort to address this, anadromous Arctic charr were collected from the Deception River watershed in the l...
The subcellular compartmentalization of metals within aquatic organisms reflects their internal behavior after metal uptake and can provide important information about their potential toxicity. Commonly, the fractionation protocol used to determine subcellular metal partitioning in aquatic organisms consists of mechanically homogenizing the tissue,...
MicroRNAs (miRNAs) are a class of small non-coding RNA that control multiple biological processes through negative post-transcriptional regulation of gene expression. Recently a role of miRNAs in the response of aquatic organisms to environmental toxicants emerged. Toxicant-induced changes in miRNA expression might then represent novel biomarkers t...
Understanding how organisms cope with global change is a major question in many fields of biology. Mainly, understanding the molecular mechanisms supporting rapid phenotypic changes of organisms in response to stress and linking stress-induced molecular events to adaptive or adverse outcomes at the individual or population levels remain a major cha...
The distribution of As, Cd, Cu and Se among biomolecules of different molecular weight (MW) in the heat-treated cytosolic fraction of livers and gonads of white suckers (WS; Catostomus commersonii) collected in a reference lake and in a lake subject to multi-metal contamination was investigated. Distribution profiles were obtained by separation of...
In the present study, we examined the subcellular distribution of metals and metalloids (As, Cd, Cu, Se and Zn) in the liver and gonads of wild white suckers (Catostomus commersonii) collected downstream from a metal mining operation (exposure area) and in a reference area. Metal partitioning among potentially metal-sensitive fractions (heat-denatu...
Metal exposure may lead to accumulation and toxicity in aquatic species. Once metals enter living organisms, they can penetrate into their cells and cause deleterious effects. Alternately, metals can be detoxified by binding to molecules designed to sequester them and prevent them from exerting their toxic effects, such as metallothioneins (MT) and...
Discharges from metal mining operations may lead to metal accumulation and toxicity in aquatic species. Once metals enter cells, they can bind to sensitive components and cause deleterious effects. Nevertheless, metals can also be detoxified by binding to molecules designed to sequester them, limiting their toxicity. The objectives of this study we...
MicroRNAs (miRNAs) are a class of small non-coding RNA. These 20-24 nucleotides-long sequences associate with the 3’-untranslated region (3’-UTR) of target messenger RNAs (mRNAs), and post-transcriptionally regulate the expression of numerous genes by mediating translational repression or mRNA degradation. In mammals, more than 50% of mRNAs are pre...
An international sampling program investigating the causes of the decline of American eels (Anguilla rostrata) and European eels (Anguilla anguilla) in the St. Lawrence (Canada) and Gironde (France) rivers systems provided the opportunity to compare early growth of eels of each species among habitats using back-calculated size-at-age from 1 to 5 ye...
In this study, we tested the hypothesis that metal exposure affected the normal thermal response of cell membrane FA composition and of elongase and desaturase gene transcription levels. To this end, muscle and brain membrane FA composition and FA desaturase (fads2, degs2 and scd2) and elongase (elovl2, elovl5 and elovl6) gene transcription levels...
Biomolecules involved in handling cytosolic metals in the liver of the yellow perch (Perca flavescens) were characterized in juvenile fish collected from four lakes constituting metal contamination gradients. Using size-exclusion liquid chromatography coupled to an inductively-coupled mass spectrometer (SEC-ICP-MS), we determined metal distribution...
Since the early 1980s, populations of American (Anguilla rostrata) and European eels (Anguilla anguilla) have suffered a sharp decline. The causes of their decline are likely multifactorial and include chemical pollution. A field study was conducted in eight sites varying in organic and metal contamination along the St. Lawrence (Eastern Canada) an...
Municipal effluents are recognized as major sources of pollutants that could compromise fish health and reproduction. The purpose of this study was to examine and compare the reproductive toxicity of low-and high-risk municipal effluents to fathead minnows (Pimephales promelas) exposed for 12 weeks in the laboratory. After the exposure period, repr...
The purpose of this study was to compare the toxicity of two major municipal effluents subjected to different treatment processes: a physico-chemically treated effluent (high-risk effluent) and a biofiltered/ UV-disinfected effluent (low-risk effluent). Juvenile fathead minnows were exposed to increasing concentrations of the high-risk and low-risk...
Discharges from metal mining operations may lead to metal accumulation and toxicity in exposed aquatic species. Indeed, once metals enter cells, they can bind to sensitive components and cause deleterious effects. Nevertheless, metals can also be detoxified by binding to molecules designed to sequester them and limiting their toxic effects. The obj...
The aim of this study was to investigate the combined effects of temperature and metal contamination (cadmium and nickel) on phospholipid fatty acid composition, antioxidant enzyme activities and lipid peroxidation in fish. Yellow perch were acclimated to two different temperatures (9 °C and 28 °C) and exposed either to Cd or Ni (respectively 4 μg/...
Aquatic ecosystems are subjected to a variety of man-induced stressors but also vary spatially and temporally due to variation in natural factors. In such complex environments, it remains difficult to detect, dissociate and evaluate the effects of contaminants in wild organisms. In this context, the aim of this study was to test whether the hepatic...
American (Anguilla rostrata) and European (Anguilla anguilla) eel populations are declining since the 1980s, and contamination is thought to play a role. To determine the influence of organic (organochlorinated pesticides (OCPs), polybrominated diphenyl ethers (PBDEs), polychlorinated biphenyls (PCBs)) and inorganic (Zn, As, Cd, Cu, Pb, Cr, Ni, Ag,...
Detecting and separating specific effects of contaminants in a multi-stress field context remain a major challenge in ecotoxicology. In this context, the aim of this study was to assess the usefulness of a non-invasive transcriptomic method, by means of a complementary DNA (cDNA) microarray comprising 1000 candidate genes, on caudal fin clips. Fin...
Recent local adaptation to pollution has been evidenced in several organisms inhabiting environments heavily contaminated by metals. Nevertheless, the molecular mechanisms underlying adaptation to high metal concentrations are poorly understood, especially in fishes. Yellow perch (Perca flavescens) populations from lakes in the mining area of Rouyn...
Measuring the effects of selection on the genome imposed by human-altered environment is currently a major goal in ecological genomics. Given the polygenic basis of most phenotypic traits, quantitative genetic theory predicts that selection is expected to cause subtle allelic changes among covarying loci rather than pronounced changes at few loci o...
Perch have been used for ecotoxicological research for nearly a half-century owing to their overlapping geographic distribution with large-scale industrial activities in the Northern Hemisphere. Because they can withstand relatively high concentrations of environmental contaminants, perch are often found in more contaminated habitats than those tha...
Since the early 1980s, the population of European eels (Anguilla anguilla) has dramatically declined. Nowadays, the European eel is listed on the red list of threatened species (IUCN Red List) and is considered as critically endangered of extinction. Pollution is one of the putative causes for the collapse of this species. Among their possible effe...
We determined the intracellular compartmentalization of the trace metals Ag, As, Cd, Ni, Pb and Tl in the livers of yellow eels collected from the Saint Lawrence River system in Canada (Anguilla rostrata) and in the area of the Gironde estuary in France (Anguilla anguilla). Differential centrifugation, NaOH digestion and thermal shock were used to...
Identifying specific effects of contaminants in a multi-stress field context remain a challenge in ecotoxicology. In this context, "omics" technologies, by allowing the simultaneous measurement of numerous biological endpoints, could help unravel the in situ toxicity of contaminants. In this study, wild Atlantic eels were sampled in 8 sites present...
There is increasing evidence that pollutants may cause diseases via epigenetic modifications. Epigenetic mechanisms such as DNA methylation participate in the regulation of gene transcription. Surprisingly, epigenetics research is still limited in ecotoxicology. In this study, we investigated whether chronic exposure to contaminants experienced by...
Several reasons may account for the decline of American (Anguilla rostrata) and European (Anguilla anguilla) eel populations. This study aims at developing a better understanding of eel reproductive biology, and to investigate the effects of contaminants on their reproductive capacity. Eels bioaccumulate contaminants during their long continental g...
This study is part of an international program ‘IMMORTEEL’ investigating the possible contribution of habitat contamination in the decline of Atlantic eels. Biomarker responses and muscle concentrations of persistent organic contaminants (POPs) were examined in European eels (Anguilla anguilla) and American eels (Anguilla rostrata) in the Gironde a...
To unambiguously interpret the impacts of environmental contamination on fish condition, it is important to understand the confounding effects of natural environmental factors. In this study, we measured the effects of temperature (11, 20, and 28 °C), oxygen level, and dietary restriction on yellow perch (Perca flavescens) using biometric endpoints...
In this experiment, we studied the transcriptional and functional (enzymatic) responses of yellow perch (Perca flavescens) to metal stress, with a focus on oxidative stress and vitamin A metabolism. Juvenile yellow perch were exposed to two environmentally relevant concentrations of waterborne cadmium (Cd) and nickel (Ni) for a period of 6 weeks. K...
In summer 2001, the St. Lawrence River (Québec, Canada) experienced perhaps the largest massive fish kill of its history, with more than 25 000 carp (Cyprinus carpio) found dead. This experiment therefore investigated the effects of heat stress on the gene transcription level of heat shock protein 70, cytochrome c oxidase and mitochondrial superoxi...
The molecular mechanisms underlying nickel (Ni) and cadmium (Cd) toxicity and their specific effects on fish are poorly understood. Documenting gene transcription profiles offers a powerful approach toward identifying the molecular mechanisms affected by these metals and to discover biomarkers of their toxicity. However, confounding environmental f...
Pollution can drive rapid evolutionary change in wild populations. This study targets functional polymorphisms of chronically metal-contaminated wild yellow perch (Perca flavescens). A de novo transcriptome scan contrasted subsets of individuals from clean (n = 16) and contaminated (n = 16) lakes to identify 87 candidate annotated coding SNPs. Cand...
In a recent study on indigenous yellow perch chronically exposed to metals, we reported a negative correlation between liver metal concentration and liver transcription levels of genes encoding for enzymes involved in the metabolism of retinoids. We therefore speculated that metals, and especially the non-essential metal Cd, could alter the metabol...
Nickel (Ni) is the 22nd most abundant element and is ubiquitous in marine and freshwater ecosystems. Nickel concentrations increase in aquatic systems that receive inputs from urban and industrial effluents. At pH values common to most aquatic systems, Ni speciation is dominated by Ni2+ with increasing hydroxide complexation with increasing pH valu...
Metals have been present in the environment since the origin of our planet. Life has evolved in their presence, incorporating many of them in essential molecules and metabolic processes and developing protective mechanisms against both non-essential metals and excess essential metals. Anthropogenic metal contamination of terrestrial and aquatic sys...
Enzymes representing a variety of metabolic pathways were examined in yellow perch (Perca flavescens) collected from a metal-contaminated region (Rouyn-Noranda, Québec, Canada) to determine which were most closely related to fish condition factor, pyloric caeca weight, and visceral lipid accumulation, as well to seek a better understanding of the i...
Despite its role as an essential micronutrient, copper (Cu) can be present in aquatic ecosystems at concentrations able to cause adverse health effects on aquatic organisms. Although Cu is acquired by fish by either water or diet, studies that have investigated Cu impacts in fish have mainly focused on the toxicity of waterborne Cu. Moreover, as th...
Given the inherent variability of aquatic systems, predicting the in situ effects of contaminants on such ecosystems still represents a major challenge for ecotoxicology. In this context, transcriptomic tools can help identify and investigate the mechanisms of toxicity beyond the traditional morphometric, physiological and population-level endpoint...
This study examined seasonal variations in tissue metal contamination and physiological condition of yellow perch (Perca flavescens) from a clean lake (Halfway Lake) and a metal-contaminated environment (Whitson Lake) in spring, summer, and fall of 1999. Dietary metal content influenced liver metal concentrations, especially for cadmium. Fulton's c...
Optimal foraging behaviour in walleye (Sander vitreus) was tested in eight lakes: four containing large prey (cisco, Coregonus artedi) and four without cisco. All eight lakes contained small prey (yellow perch, Perca flavescens). Activity costs and growth potential of walleye were estimated using white muscle enzymes. Anaerobic capacity, measured b...
The aim of this study was to examine how the biochemical composition of tissues varied with growth rate and condition in juvenile Atlantic cod (Gadus morhua) caught in the wild and kept in captivity. The hepatosomatic index, brain water content, and muscle sarcoplasmic protein content as well as the activities of phosphofructokinase, lactate dehydr...
In this study, the general condition, swimming capacities, and tissue metabolic capacities and metal concentrations in wild yellow perch (Perca flavescens) were examined from a range of metal-contaminated lakes near Sudbury, Ontario. Fish exposed to elevated environmental cadmium and copper concentrations showed higher liver concentrations of these...
This study evaluated the >400-fold tolerance to acute waterborne Cd of a metal-tolerant fish, yellow perch (YP, Perca flavescens), relative to a sensitive model fish, rainbow trout (RBT, Oncorhynchus mykiss), from the perspective of the acute Cd biotic ligand model (BLM). Three-hour gill binding characteristics for Cd and its competitor, Ca, in bot...
The metabolic organization of swimming muscles from anadromous cisco (Coregonus artedii) and lake whitefish (Coregonus clupeaformis) sampled in two rivers presenting different regimes of migratory difficulty and temperature was compared. Cisco muscle showed an increased aerobic capacity in the river where the fishes' migration is longer, as shown b...
The aim of the current study was to investigate effects of temperature and a mixture of herbicides on the physiological status of the bivalve Mya arenaria. Bivalves acclimated to two temperatures (7 and 18°C) were exposed for 28 d to 0.01 mg/L of a pesticide formulation containing dichlorophenoxyacetic acid (2,4-D), 2-(2-methyl-4-chlorophenoxy) pro...
Physiological correlates of seasonal growth patterns were measured in lake trout Salvelinus namaycush from two populations with contrasting diets (zooplankton-dominated diet in Louisa Lake; fish-dominated diet in Opeongo Lake). Fish in Opeongo Lake grew faster and were in better condition than fish in Louisa Lake. The most prominent biochemical dif...
Although the selective pressures of commercial fishing are well known, few studies have examined this phenomenon in recreational fisheries. This study used a unique population of largemouth bass (Micropterus salmoides) with lines bred for low (LVF) and high (HVF) vulnerability to recreational angling. We evaluated whether differential vulnerability...
The aim of the current study was to investigate effects of temperature and a mixture of herbicides on the physiological status of the bivalve Mya arenaria. Bivalves acclimated to two temperatures (7 and 18°C) were exposed for 28 d to 0.01 mg/L of a pesticide formulation containing dichlorophenoxyacetic acid (2,4-D), 2-(2-methyl-4-chlorophenoxy) pro...
Early-life stages of fathead minnows were exposed to environmentally relevant concentrations of aqueous and dietary nickel and thallium and metal accumulation was monitored from the embryo until the larvae reached 21 days after hatching. During and after metal exposure, 6 toxicity endpoints were measured: time to hatch, embryo survival rate, routin...
The energetic and physiological status of parental smallmouth bass Micropterus dolomieu was investigated across the majority of their latitudinal range at the onset and near the end of care. Variables such as tissue lipid stores, plasma indicators of nutritional status and chronic stress and white muscle were used to define energetic and physiologi...
Although impairment of aerobic capacities has been reported in metal-contaminated wild fish, little is known about the direct toxicity of the metals themselves at the low concentrations found in the field compared to indirect consequences mediated by metal effects on ecological variables such as prey type and abundance, predation and competition. T...
Because fish take up metals from prey, it is important to measure factors controlling metal transfer between these trophic levels so as to explain metal bioaccumulation and effects in fish. To achieve this, we exposed two types of invertebrates, an oligochaete (Tubifex tubifex) and a crustacean (Daphnia magna), to environmentally relevant concentra...
Predation is considered one of the main costs to reproduction but is rarely examined from a physiological perspective. In particular, little is known about the influence of brood predation pressure on the physiology of parents engaged in care. Brood defense, even when there is no direct threat to the parent, can be costly as it requires constant vi...
Variations in fish condition, pyloric caeca (PC) mass and tissue metal concentrations were examined in two consecutive summers in yellow perch collected along two polymetallic gradients in Canada, Sudbury (ON) and Rouyn-Noranda (QC). The potential of PC mass variations to help interpret food web-mediated changes in condition was also evaluated. The...
To investigate the mechanisms involved in metal stress in wild fish, yellow perch (Perca flavescens) were collected in eight lakes of the Rouyn-Noranda and Sudbury regions (Canada). Due to mining and smelting activities, these two regions indeed present a broad contamination gradient in metal concentrations (Cd, Cu, Zn and Ni; water, sediment and p...
In this study, we examine the relative contribution of water and live prey (Tubifex tubifex) as sources of nickel (Ni) and thallium (Tl) in juvenile fathead minnows (Pimephales promelas). Overall, both water and prey were important sources of metals for our fish, although only approximately 35% of the metal estimated available for trophic transfer...
This study on yellow perch (Perca flavescens) examines a series of enzymatic markers and the relative weights of pyloric caeca and visceral lipids, their response to changes in feeding regime and their potential use to infer recent changes in growth rate and fish condition. Fish were exposed to four different feeding regimes for 12 weeks resulting...
Wild yellow perch (Perca flavescens) were sampled from five lakes in each of two metal contamination gradients in Sudbury, Ontario, Canada (n = 1324) and Rouyn-Noranda, Québec, Canada (n = 1125) in the spring and summer of 2002 and 2003, respectively, in order to examine growth patterns, longevity, and the influences of season and region on fish co...
The influences of metal contamination, fish size, season, and region on tissue metabolic capacities and protein concentrations were examined in yellow perch from two metal gradients (Sudbury, Ontario, and Rouyn-Noranda, Québec, Canada) in two seasons (spring and summer). In general, increased tissue Cu and Cd contamination was associated with lower...
This review summarizes some of the main findings of our work with the Metals in the Environment Research Network examining seasonal and regional effects on metal accumulation, growth, condition, and physiology in wild yellow perch (Perca flavescens) from 10 lakes comprising two metal contamination gradients in the industrial regions of Sudbury, Ont...
This study examined relationships among water, sediment, diet, and fish tissue metal (Cd, Cu, Ni, Se, and Zn) concentrations in yellow perch from metal gradients in two regions (Sudbury (S), Ontario, and Rouyn-Noranda (RN), Québec, Canada) in two seasons (spring and summer). The objectives of this study were (1) to examine the influences of aqueous...
Depending on such factors as the intensity and duration of the exposure, and the genetic diversity and connectedness of the starting population, exposure to elevated metal concentrations can result in population level alterations such as demographic bottlenecks or metal-induced selection. These processes can be revealed using a population genetic a...
Yellow perch (Perca flavescens) are ubiquitous in lakes all around northeastern North America. They are an important component of their aquatic food webs, as an abundant species that feed successively on zooplankton, benthos and fish as they grow. They are tolerant to metals and may be found in lakes contaminated by metal mining and smelting where...
Sub-cellular metal distributions were studied in indigenous yellow perch (Perca flavescens) collected from eight lakes located along a cadmium (Cd), copper (Cu), nickel (Ni) and zinc (Zn) concentration gradient. Ambient dissolved metal concentrations were measured to evaluate exposure and total hepatic metal concentrations were determined as a meas...
The consequences of low-level metal exposure to early life stages of fathead minnows (Pimephales promelas) were investigated along a contamination gradient near Sudbury, Canada. Field exposures resulted in elevated hatching time and increased mortality in metal-contaminated lakes, in contrast to laboratory exposures where no effects were observed....
The purpose of this study was to examine relationships among water, sediment, and fish tissue metal concentrations as they relate to fish diversity, tissue metal accumulation, and fish morphometric and reproductive condition. Fish were captured in 12 lakes near Sudbury, Ontario, Canada, that ranged in their degree of metal contamination. In general...
Activity costs can account for a major proportion of fish energy budgets and may trade off against observed growth rates in wild fish populations. Recent approaches to estimating activity costs in situ have used a contaminant-bioenergetic mass balance modelling approach, allowing for a broader examination of activity costs among populations compare...
Pairs of reproductively mature male three-spined stickleback (Gasterosteus aculeatus) were introduced into unfamiliar aquaria and observed until one male became dominant. Skin carotenoid content, morphometric indexes, and metabolic capacities of the axial and pectoral muscles were examined to establish whether morphological or physiological paramet...
