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Bibliography of the Maurice Lamontagne Institute

Catherine M. COUILLARD

COUILLARD, C.M., B. LÉGARÉ, A. BERNIER, Z. DIONNE, 2011. Embryonic exposure to environmentally relevant concentrations of PCB126 affect prey capture ability of Fundulus heteroclitus. Mar. Environ. Res., 71(4): 257-265 .

Early life stages from a marine fish species, Fundulus heteroclitus, were exposed to sublethal doses of 3,3',4,4',5 pentachlorobiphenyl (PCB126) to evaluate its effects on ecologically relevant responses: growth and behavior. A few hours after fertilisation, eggs were treated topically with PCB126 (2.5–50 pg egg-1). Four days post-hatching (dph), morphological changes (body length and malformations), spontaneous locomotor activity (active swimming speed, rate of travel, % inactivity), prey capture ability (Artemia franciscana nauplii) and whole body EROD activity were evaluated in larvae. Untreated larvae collected at 0.5, 1, 2, 3, 4 dph were also examined. PCB126 did not increase the mortality or malformation rates. Body length and spontaneous locomotor activity were altered only in larvae treated with the highest dose. Treatment with PCB126 caused a dose-responsive reduction in prey capture ability (rate of decline in the number of Artemia) and induction of EROD activity. The lowest observed effective dose for both of these responses was 5.0 pg PCB126 egg-1 or 5.0 TCDD-toxic equivalents pg g-1 egg, using a TCDD-toxic equivalent factor of 0.005 and an egg mass of 5 mg. Prey capture efficiency (number of Artemia captured per feeding strike) was reduced at ≥10.0 pg egg-1. In untreated developing larvae, prey capture ability and efficiency increased as post-hatching development progressed and EROD activity remained low. The pattern of behavioral responses observed in PCB126-exposed Fundulus larvae differed from that observed in less-developed larvae indicating that other mechanisms than retarded development were involved. Behavioral dysfunction was a more sensitive response to PCB126 than morphological alterations and it occurred at environmentally relevant concentrations.©2011 Elsevier Ltd.

BLANAR, C.A., D.J. MARCOGLIESE, C.M. COUILLARD, 2011. Natural and anthropogenic factors shape metazoan parasite community structure in mummichog (Fundulus heteroclitus) from two estuaries in New Brunswick, Canada. Folia Parasit., 58(3): 240-248 .

Previously published multidisciplinary studies in the Miramichi and Bouctouche rivers (New Brunswick, Canada) noted significant changes in fish health parameters, including elevated tissue levels of organic contaminants and a wide range of physiological disturbances, in mummichog Fundulus heteroclitus (L.) from a site on the Miramichi River that received bleached kraft pulpmill and municipal effluent. The present study reports differences in the abundance of individual parasite species, as well as parasite infracommunity and component community composition, in mummichog from both rivers. These differences were evaluated in relation to host (size, condition, immune function, tissue organochlorine contaminant levels) and environmental (faecal coliform counts, salinity, temperature) data derived from the previously published studies. Overall, 18 parasite species were identified, the most common of which were Ascocotyle sp. Larv., Ornithodiplostomum sp. Larv., Posthodiplostomum sp. Larv., and Proteocephalus filicollis (Rudolphi, 1802). There were broad differences in parasite community structure and composition between rivers and within rivers, the most prominent pattern being a pronounced difference between sites in the upper and lower estuary of each river that was likely driven by salinity. Mean infracommunity richness was also positively related to faecal coliforms (considered here as a surrogate measure of eutrophication via municipal sewage), and both were highest at the most polluted site. We noted no other significant relationships. Thus our data suggest that the parasite communities in these two estuaries were primarily structured by large upstream/downstream ecological gradients in salinity, and secondarily by eutrophication due to pollution by municipal and industrial effluents. Overall, our results highlight the value of coordinated multidisciplinary studies for understanding the factors that shape parasite abundance and community structure.© 2011 Institute of Parasitology, Biology Centre ASCR

MARTEL, L., M. FOURNIER, G. TRIFFAULT-BOUCHET, D. BERRYMAN, I. GUAY, P.G.C. CAMPBELL, M. LEBEUF, C. COUILLARD, L. PARENT, J. PELLERIN, P. BENOÎT, E. LACROIX, L.E. BURRIDGE (eds), 2010. Proceedings of the 36th Annual Aquatic Toxicity Workshop : September 27 to 30, 2009, La Malbaie, Québec ; Comptes rendus du 36 ième atelier annuel sur la toxicité aquatique : du 27 au 30 septembre 2009, La Malbaie, Québec. Can. Tech. Rep. Fish. Aquat. Sci. ; Rapp. tech. can. sci. halieut. aquat., 2883, 199 p .

MALTAIS, D., R.L. ROY, C.M. COUILLARD, 2010. Hybrid ELISAs for vitellogenins of the endangered Copper Redhorse (Moxostoma hubbsi) and the Shorthead Redhorse (Moxostoma macrolepidotum (Cypriniformes, catostomidae). Ecotoxicol. Environ. Saf., 73(5): 883-892 .

The shorthead redhorse (sr) Moxostoma macrolepidotum is endemic in North America, while in Canada the copper redhorse (cr) Moxostoma hubbsi is classified as endangered. A commercial heterologous carp vitellogenin (VTG) sandwich ELISA underestimates VTGs in these species. Hybrid ELISAs, using anti-carp VTG antibodies and purified sr- and cr-VTGs as standards, were validated to measure VTGs in plasma and surface mucus of redhorse species. The hybrid ELISAs showed good precision, sensitivity and accuracy. Following induction with β-estradiol 3-benzoate (E2B), levels of plasma VTG (mean ± SEM) in male sr increased from 2.7 ± 1.5 μg/ml to 16.5±2.2 mg/ml. In immature cr, plasma VTG increased to 70.1±13.8 mg/ml after induction, from an initial value of 37.7±51.0 μg/ml. Levels of VTG in mucus from E2B-injected fish were highly correlated (p<0.0001) with levels in plasma, but not in a non-induced mature female. Hybrid assays are a good compromise between homologous and heterologous assays, especially for small-bodied or endangered fish species. The performance of the hybrid assays strongly suggests they could be used to determine exposure of these species to estrogenic contaminants and contribute to restoration efforts of the copper redhorse. Crown Copyright ©2010 Elsevier Inc.

COUILLARD, C.M., 2009. Utilisation des poissons pour évaluer les effets biologiques des contaminants dans l'estuaire du Saint-Laurent et le fjord du Saguenay;Use of fish to assess biological effects of contaminants in the St. Lawrence Estuary and Saguenay Fjord. Rev. Sci. Eau;J. Water Sci., 22(2): 291-314 .

Aquatic organisms in the St. Lawrence Estuary (SLE) and the Saguenay Fjord (SF) are exposed to complex mixtures of toxic compounds which can have deleterious impacts on populations, alone or in combination with other environmental factors. The purpose of this paper is to summarize information about biological effects of contaminants in the SLE and SF obtained using sentinel fish species. Three case studies demonstrate the complementary nature of the information acquired using different sentinel species. Studies in American eel (Anguilla rostrata) show how migratory fish can be an important vector of contamination for high level predators in the SLE. Preneoplastic liver lesions in migrating eels, likely related to an exposure to polycyclic aromatic hydrocarbons (PAHs) in their growing areas, are an example of a long-term effect of contaminants which do not persist in fish tissues. DNA adducts were detected in resident SLE Atlantic tomcod (Microgadus tomcod) and can be used to compare the level of exposure to genotoxic PAHs between the SLE and other estuaries of the Atlantic coast. Studies in tomcod have also revealed an interaction between their winter fasting period and persistent organic compounds (POPs) leading to a transitory increase in concentrations ofPOPs in the liver and to hepatic dysfunction. Field samplings in association to in situ cage exposures and laboratory experiments have been used in American plaice (Hipoglossoides pfatessoides) exposed to contaminated sediments from Baie des Anglais, to demonstrate immune alterations causing increased susceptibiliry to infectious diseases. Future studies on biological effects of contaminants in fish in the SLE and SF should pursue the development of biomarkers for different groups of contaminants, and use them in key fish species, sampled at critical stages of their life cycle, in studies combining different multistressors experimental approaches to field monitoring.©2009 RSE inc.

COUILLARD, C.M., B. LAPLATTE, É. PELLETIER, 2009. A fish bioassay to evaluate the toxicity associated with the ingestion of benzo[a]pyrene-contaminated benthic prey. Environ. Toxicol. Chem., 28(4): 772-781 .

A bioassay was developed to assess the toxic effects of ingested prey contaminated by polycyclic aromatic hydrocarbons (PAHs) using the teleost Fundulus heteroclitus as a predator and the polychaete Nereis virens as a benthic vector. Ten groups of nine male adult Fundulus were exposed for 21 d to 10 different diets of Nereis contaminated with benzo[a]pyrene (BaP) by spiking dead Nereis with BaP (spiked Nereis [SN] diets, 0–26 μg of BaP per gram dry wt) or by exposing living Nereis to a diet, to sediments, or to both contaminated with BaP (exposed Nereis [EN] diets, 0–16 μg/g dry wt). Another group was exposed to commercial fish food, used as reference diet. Condition and prevalence of histopathological changes were not affected. Exposure to the SN diets containing at least 3.5 μg of BaP per gram dry weight caused an induction of ethoxyresorufin-O-deethylase activity in the intestine but not in the liver. In contrast, fish exposed to the highest doses (≥13.4 μg of BaP per gram dry wt) had increased cellular proliferation rate in the liver but not in the intestine. Quantifiable levels of free BaP tetrol–like metabolites were detected in the bile of fish exposed to diets containing more than 6.8 μg/g dry weight of BaP, and exhibited a dose–response relationship in fish exposed to SN diets. For a similar dose of BaP, EN and SN diets had similar effects. Thus, the BaP metabolic products that could have been produced in Nereis apparently did not contribute to the biomarkers responses. This bioassay can be applied to a variety of prey contaminated naturally or experimentally with PAHs. The present study supports the use of intestinal biomarkers, in addition to hepatic biomarkers, in environmental monitoring to assess the impact of dietary exposure to PAHs.©2009 SETAC

ROSS, P.S., C.M. COUILLARD, M.G. IKONOMOU, S.C. JOHANNESSEN, M. LEBEUF, R.W. MACDONALD, G.T. TOMY, 2009. Large and growing environmental reservoirs of Deca-BDE present an emerging health risk for fish and marine mammals. Mar. Pollut. Bull., 58(1): 7-10 .

Polybrominated diphenyl ethers (PBDEs) have been the subject of intense scientific and regulatory scrutiny during recent years. Of the three commercial forms (Penta, Octa and Deca) of PBDEs that have been widely used as flame retardants in textiles, furniture upholstery, plastics, and electronics, only Deca-BDE remains on the general market in North America, while a recent ruling of the European Court spells an impending end to its use in Europe. We review here highlights of aquatic research documenting the rapid emergence of PBDEs as a high priority environmental concern in Canada. PBDEs are being introduced in large quantities to the aquatic environment through sewage discharge and atmospheric deposition. In certain environmental compartments, the single congener BDE-209, the main ingredient in the Deca-BDE formulation, has surpassed the legacy PCBs and DDT as the top contaminant by concentration. Limited biomagnification of BDE-209 in aquatic food webs reflects its high log Kow and preferential partitioning into the particle phase. As a result, large environmental reservoirs of BDE-209 are being created in sediments, and these may present a long-term threat to biota: BDE-209 breaks down into more persistent, more bioaccumulative, more toxic, and more mobile PBDE congeners in the environment. Crown Copyright ©2008 Published by Elsevier Ltd.

FORTIN, M.-G., C.M. COUILLARD, J. PELLERIN, M. LEBEUF, 2008. Effects of salinity on sublethal toxicity of atrazine to mummichog (Fundulus heteroclitus) larvae. Mar. Environ. Res., 65(2): 158-170 .

Early life stages from a marine fish species, Fundulus heteroclitus, were exEarly life stages from a marine fish species, Fundulus heteroclitus, were exposed to sublethal doses of 3,30,4,40,5 pentachlorobiphenyl (PCB126) to evaluate its effects on ecologically relevant responses: growth and behavior. A few hours after fertilisation, eggs were treated topically with PCB126 (2.5e50 pg egg1). Four days post-hatching (dph), morphological changes (body length and malformations), spontaneous locomotor activity (active swimming speed, rate of travel, % inactivity), prey capture ability (Artemia franciscana nauplii) and whole body EROD activity were evaluated in larvae. Untreated larvae collected at 0.5, 1, 2, 3, 4 dph were also examined. PCB126 did not increase the mortality or malformation rates. Body length and spontaneous locomotor activity were altered only in larvae treated with the highest dose. Treatment with PCB126 caused a dose-responsive reduction in prey capture ability (rate of decline in the number of Artemia) and induction of EROD activity. The lowest observed effective dose for both of these responses was 5.0 pg PCB126 egg1 or 5.0 TCDD-toxic equivalents pg g1 egg, using a TCDD-toxic equivalent factor of 0.005 and an egg mass of 5 mg. Prey capture efficiency (number of Artemia captured per feeding strike) was reduced at 10.0 pg egg1. In untreated developing larvae, prey capture ability and efficiency increased as post-hatching development progressed and EROD activity remained low. The pattern of behavioral responses observed in PCB126-exposed Fundulus larvae differed from that observed in less-developed larvae indicating that other mechanisms than retarded development were involved. Behavioral dysfunction was a more sensitive response to PCB126 than morphological alterations and it occurred at environmentally relevant concentrations.posed to sublethal doses of 3,30,4,40,5 pentachlorobiphenyl (PCB126) to evaluate its effects on ecologically relevant responses: growth and behavior. A few hours after fertilisation, eggs were treated topically with PCB126 (2.5e50 pg egg1). Four days post-hatching (dph), morphological changes (body length and malformations), spontaneous locomotor activity (active swimming speed, rate of travel, % inactivity), prey capture ability (Artemia franciscana nauplii) and whole body EROD activity were evaluated in larvae. Untreated larvae collected at 0.5, 1, 2, 3, 4 dph were also examined. PCB126 did not increase the mortality or malformation rates. Body length and spontaneous locomotor activity were altered only in larvae treated with the highest dose. Treatment with PCB126 caused a dose-responsive reduction in prey capture ability (rate of decline in the number of Artemia) and induction of EROD activity. The lowest observed effective dose for both of these responses was 5.0 pg PCB126 egg1 or 5.0 TCDD-toxic equivalents pg g1 egg, using a TCDD-toxic equivalent factor of 0.005 and an egg mass of 5 mg. Prey capture efficiency (number of Artemia captured per feeding strike) was reduced at 10.0 pg egg1. In untreated developing larvae, prey capture ability and efficiency increased as post-hatching development progressed and EROD activity remained low. The pattern of behavioral responses observed in PCB126-exposed Fundulus larvae differed from that observed in less-developed larvae indicating that other mechanisms than retarded development were involved. Behavioral dysfunction was a more sensitive response to PCB126 than morphological alterations and it occurred at environmentally relevant concentrations.

COUILLARD, C.M., M. LEBEUF, B. LÉGARÉ, S. TROTTIER, 2008. Effects of diazinon on mummichog (Fundulus heteroclitus) larvae produced from eggs differentially treated with PCB126. Arch. Environ. Contam. Toxicol., 54(2): 283-291 .

During their formation, fish eggs receive a load of contaminants including polychlorinated biphenyls (PCBs) from their mother and then, after spawning, are exposed to pesticides present in water. This is the first study investigating the interaction between PCBs and organophosphorous pesticides in fish. The effect of diazinon was evaluated in mummichog (Fundulus heteroclitus) larvae produced from eggs differentially treated with 3,3′,4,4′,5 pentachlorobiphenyl (PCB126). A few hours after fertilization, eggs were treated topically with a solution of PCB126 (100 pg/μl) in dimethyl sulfoxide (DMSO) (Group P), DMSO (Group D), or not treated (Group N). Newly hatched larvae from Groups P and D were exposed to diazinon (125–12,900 ng/L) in saltwater and Group N larvae to saltwater alone. Diazinon caused a dose-responsive inhibition of cholinesterase (ChE) activity at environmentally realistic concentrations (≥361 ng/L), with up to 85 % inhibition at 12,900 ng/L. Body length was also inversely related to diazinon at concentrations ≥361 ng/L and was significantly reduced (by 4 %) at 12,900 ng/L compared to controls. Mummichog larvae were highly sensitive to PCB126 with an eightfold induction of the activity of ethoxyresorufin-O-deethylase at a dose of 710 pg PCB126 or 3.6 pg TCDD-TEQ/g wet weight. Treatment with PCB126 also caused a slight reduction in body length but no effect on ChE activity. This study indicates that the effects of PCB126 and diazinon on body length are cumulative because no significant synergistic or antagonistic interactions were observed. Longer term studies with several doses of PCB126 are needed to fully assess the overall impact of joint exposure to diazinon and PCB126 on growth and survival of fish larvae.©2007 Springer Science+Business Media, LLC.

ROSS, P.S., C.M. COUILLARD, M. IKONOMOU, S. JOHANNESSEN, M. LEBEUF, R. MACDONALD, G. TOMY, 2008. Polybrominated Diphenylethers (PBDEs) in the Canadian marine environment : an emerging health risk for fish, marine mammals and their habitat ; Les polybromodiphényléthers (PBDEs) dans le milieu marin canadien : un risque émergent pour la santé des poissons, des mammifères marins et pour leur habitat. DFO, Canadian Science Advisory Secretariat, Research Document ; MPO, Secrétariat canadien de consultation scientifique, Document de recherche, 2008/036, 27 p .

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Of the three forms (penta, octa and deca) of polybrominated diphenylethers (PBDEs) that have been widely used in textiles, furniture upholstery, plastics, and electronics, only deca-BDE remains on the market in Canada. DFO and other researchers have documented the rapid emergence of PBDEs, including deca-BDE, as a priority concern in the marine and freshwater environments in Canada. In many matrices, BDE-209, the main ingredient in deca-BDE, has surpassed PCBs and DDT as the number one contaminant. PBDEs are being introduced to the marine environment by sewage discharge and atmospheric deposition. Recent DFO research shows that BDE-209 dominates the PBDEs profile in abiotic components of the marine environment, contributing up to 80 % of the total PBDE concentration in air, water, and sediments. BDE-209 is taken up by low trophic level (e.g. shellfish and invertebrates) and terrestrial animal species, and therefore presents a risk to these species or those relying on these species for food. Although some studies have not reported results for BDE-209 because of technical difficulties in its measurement, BDE-209 has been found to biomagnify in aquatic food webs. The ready breakdown of BDE-209 into more bioaccumulative and toxic (lighter) PBDE forms in the environment presents perhaps the most insidious threat to aquatic biota. There are concerns within the scientific community about escalating risk of adverse health effects in marine biota, including invertebrates, fish and marine mammals, as well as human consumer groups including coastal First Nations communities. The endocrine-disrupting potential of PBDEs has been established in laboratory animals, fish and in seals.

COUILLARD, C.M., S.C. COURTENAY, R.W. MACDONALD, 2008. Chemical-environment interactions affecting the risk of impacts on aquatic organisms : a review with a Canadian perspective - interactions affecting vulnerability. Environ. Rev., 16: 19-44 .

As a consequence of human activity, the variability and range of environmental conditions is increasing. We review how the interactions between toxic chemicals and environmental change may affect exposure of aquatic organisms to stressful conditions and therefore alter the risk of deleterious impacts. Even in the absence of new inputs of contaminants, changing environmental conditions alters the transport, transformation and distribution of contaminants and their bioavailability. Conversely, some toxic chemicals modify the exposure of aquatic species to other stressors by affecting species distribution, behaviour or habitat. Across Canada there are a number of specific examples where interactions between contaminants and environmental change are probably harming aquatic species. In the Arctic, change in foraging brought on by change in ice regime, is a plausible mechanism to explain the marked recent increase in mercury concentrations in Beaufort Sea beluga whales. On the Pacific coast, chemical exposure by itself or in combination with other environmental factors, is a leading suspect for altered migration timing of some salmon stocks in the Fraser River leading to massive prespawning mortality. In the North Atlantic, short-term exposure of Atlantic salmon to endocrine-disrupting substances in their freshwater natal environments later leads to detectable effects at the time of their migration to saltwater. In Alberta, biotic and abiotic characteristics of the habitat dramatically affect exposure pathways and the risk of toxic effects of selenium in early life stages of trout. A better understanding of the interactions between toxic chemicals and environmental factors is a fundamental requirement for efficient management and protection of aquatic ecosystems.© 2008 NRC Canada

LEBEUF, M., C.M. COUILLARD, B. LÉGARÉ, S. TROTTIER, 2006. Effects of DeBDE and PCB-126 on hepatic concentrations of PBDEs and methoxy-PBDEs in Atlantic tomcod. Environ. Sci. Technol., 40(10): 3211-3216 .

COUILLARD, C.M., K. LEE, B. LÉGARÉ, T.L. KING, 2005. Effect of dispersant on the composition of the water-accommodated fraction of crude oil and its toxicity to larval marine fish. Environ. Toxicol. Chem., 24(6): 1496-1504 .

Newly hatched mummichog (Fundulus heteroclitus) were exposed in a 96-h static renewal assay to water-accommodated fractions of dispersed crude oil (DWAF) or crude oil (WAF) to evaluate if the dispersant-induced changes in aqueous concentrations of polycyclic aromatic hydrocarbons (PAH) affected larval survival, body length, or ethoxyresorufin-O-deethylase (EROD) activity. Weathered Mesa light crude oil (0.05-1 g/L) and filtered seawater with or without the addition of Corexit 9500® were used to prepare DWAF and WAF. At 0.2 g/L, the addition of dispersant caused a two- and fivefold increase in the concentrations of total PAH ( SPAH) and high-molecular-weight PAH (HMWPAH) with three or more benzene rings. Highest mortality rates (89 %) were observed in larvae exposed to DWAF (0.5 g/L; SPAH, 479 ng/ml). A reduction in body length was correlated with increased levels of SPAH (r2 = 0.65, p = 0.02) and not with HMWPAH. The EROD activity increased linearly with HMWPAH (r2 = 0.99, p = 0.001) and not with SPAH. Thus, chemical dispersion increased both the SPAH concentrations and the proportion of HMWPAH in WAF. Dispersed HMWPAH were bioavailable, as indicated by a significantly increased EROD activity in exposed mummichog larvae, and this may represent a significant hazard for larval fish.©2005 SETAC

COUILLARD, C.M., M. LEBEUF, M.G. IKONOMOU, G.G. POIRIER, W.J. CRETNEY, 2005. Low hepatic ethoxyresorufin-O-deethylase activity correlates with high organochlorine concentrations in Atlantic tomcod from the Canadian east coast. Environ. Sci. Technol., 24(10): 2459-2469 .

COUILLARD, C.M., WIRGIN, I.I., LEBEUF, M., LÉGARÉ, B., 2004. Reduction of cytochrome P4501A with age in Atlantic tomcod from the St. Lawrence Estuary, Canada: relationship with emaciation and possible effect of contamination.. Aquat. Toxicol. 68: 235-249 .

This study reports a reduction of ethoxyresorufin-O-deethylase (EROD) activity in large-sized, older Atlantic tomcod (Microgadus tomcod) collected in the St. Lawrence Estuary (Quebec, Canada) and investigates its relationship over a 4-year period to sex, gonadosomatic index (GSI), condition factor (CF) and cytochrome P4501A (CYP1A) mRNA levels. In addition, the concentrations of polychlorinated biphenyls (PCBs) were measured in a subsample of fish. The reduction of EROD activity with age was observed each year in both sexes and was not related to the GSI. A high proportion of large-sized fish, with a body length greater or equal to 225 mm, were emaciated (CF≤0.55). A 6-16-fold reduction of EROD activity and a 2-4-fold reduction of CYP1A mRNA levels were observed in large-sized emaciated females compared to small-sized non-emaciated females. Concentrations of PCBs in liver increased from 1000 to 4000 ng/g lipid weight as the hepatic lipid content and the CF decreased. The inter-annual variation of EROD activity was associated with the variation in CF with lowest EROD activity and CF in 1999. When emaciated fish were excluded from the analyses, EROD activity was still lower (2-5-fold) in large compared to small fish and was no longer related to CF. For similar levels of CYP1A mRNA, EROD activity was lower in large compared to small fish. Thus, there was post-transcriptional inhibition of CYP1A activity in large-sized tomcod, indicative of cellular dysfunction. This response may be related to aging, chronic exposure to toxic contaminants or to selective pressures favoring less responsive individuals. This study demonstrates that fish age, size, and CF are important variables to consider in studies using EROD activity as an indicator of environmental contamination. The main finding was that a large part of the reduction of CYP1A with age in St. Lawrence Estuary tomcod was associated with severe emaciation of a large proportion of large-sized fish. Hepatic concentrations of contaminants covaried with the CF and the effects of these two variables on CYP1A could not be discriminated.©2004 Elsevier B.V.

COUILLARD, C.M., 2002. A microscale test to measure petroleum oil toxicity to mummichog embryos. Environ. Toxicol., 17: 195-202 .

KIRCHHOFF, S., J.-M. SÉVIGNY, C.M. COUILLARD, 1999. Genetic and meristic variations in the mummichog Fundulus heteroclitus, living in polluted and reference estuaries. Mar. Environ. Res., 47: 261-283 .

COUILLARD, C.M., P.J. WILLIAMS, S.C. COURTENAY, G.P. RAWN, 1999. Histopathological evaluation of Atlantic tomcod (Microgadus tomcod) collected at estuarine sites receiving pulp and paper mill effluent. Aquat. Toxicol., 44: 263-278 .

COUILLARD, C.M., P. NELLIS, 1999. Organochlorine contaminants in mummichog (Fundulus heteroclitus) living downstream from a bleached-kraft pulp mill in the Miramichi Estuary, New Brunswick, Canada. Environ. Toxicol. Chem., 18: 2545-2556 .

CASTONGUAY, M., P.V. HODSON, C.M. COUILLARD, 1998. Chemical contamination, habitat loss and potential impact of oceanic factors on American eel recruitment in the St. Lawrence River. Pages 3-5 in The American eel in eastern Canada : stock status and management strategies : proceedings of Eel Workshop, January 13-14, 1997, Quebec City, QC (Can. Tech. Rep. Fish. Aquat. Sci., 2196) .

COURTENAY, S.C., C.M. COUILLARD, 1998. The mummichog, Fundulus heteroclitus, as a sentinel species for pulp and paper mill EEM surveys in the Atlantic coastal environment. Pages 50-54 in Proceedings of a workshop to assess alternatives to the fish survey component of the environmental effects monitoring program for canadian pulp and paper mills. DFO (Can. Tech. Rep. Fish. Aquat. Sci., 2233) .

LEBLANC, J., C.M. COUILLARD, J.-C. F. BRÊTHES, 1997. Modifications of the reproductive period in mummichog (Fundulus heteroclitus) living downstream from a bleached kraft pulp mill in the Miramichi Estuary, New Brunswick, Canada. Can. J. Fish. Aquat. Sci., 54: 2564-2573 .

It was evaluated if the time of onset, intensity, and duration of the spawning period were modified in mummichog (Fundulus heteroclitus) exposed to bleached kraft pulp mill effluents (BKME). Gonadosomatic index (GSI), percentage of mature fish, fecundity, and egg size were measured in mummichog sampled weekly between May and August 1994 at 4 (M1), 21 (M2), and 39 km (M3) sites downstream from a bleached kraft mill in the Miramichi Estuary and at two sites located upstream (B1) and 20 km downstream (B2) in a reference estuary, the Bouctouche Estuary. In the Miramichi Estuary, the onset of gonadal maturation was delayed and egg size was reduced at M1 and M2 compared with M3 whereas these parameters did not vary between sites in the Bouctouche Estuary. Fish sampled at M1 demonstrated a marked increase in reproductive investment, with higher fecundity and GSI at reproductive maxima, compared with the other sites. This response went against the upstream-downstream trend observed at other sites in both estuaries. Condition factor was not reduced at M1, suggesting that more nutrients were available than at other sites. Sources of contamination other than BKME and natural factors may contribute to these responses.

COUILLARD, C.M., P.V. HODSON, M. CASTONGUAY, 1997. Correlations between pathological changes and chemical contamination in American eels, Anguilla rostrata, from the St. Lawrence River. Can. J. Fish. Aquat. Sci., 54: 1916-1927 .

American eel (Anguilla rostrata) from the St. Lawrence River are heavily contaminated with chemicals that may be associated with increased incidence of disease and reproductive impairment. The relationship between tissue mirex concentration and body mass was used to separate eels into two groups : the proportion of eels migrating from contaminated areas (Lake Ontario and upper St. Lawrence River) increased as the migration season progressed. Vertebral malformations and basophilic foci in the liver (preneoplastic lesions) were more frequent at the end of the migratory season, when the eels were more heavily contaminated with organochlorine compounds. In contrast, mesenteric nematodes were more common in the first week of the season, when eels were less contaminated. Diameters and percentages of different stages of oocytes, and density and surface area of pigmented macrophage aggregates in the spleen, did not vary among weeks. While basophilic foci are specific biomarkers of exposure to environmental contaminants, vertebral malformations may be caused by a variety of other anthropogenic or natural factors.

DUTIL, L.T., C.M. COUILLARD, D. BÉLANGER, 1997. A processing plant survey of external lesions of American eels (Anguilla rostrata) from Lake Ontario and the St. Lawrence River, Canada. Prev. Vet. Med., 31: 19-32 .

DUTIL, L., BÉLANGER, D., C.M. COUILLARD, 1997. A telephone survey of eel fishermen regarding external lesions and mortalities of American eels (Anguilla rostrata) from Lake Ontario and the St. Lawrence River basin, Canada. Prev. Vet. Med., 31: 33-49 .

COUILLARD, C.M., P.V. HODSON, 1996. Pigmented macrophage aggregates : a toxic response in fish exposed to bleached-kraft mill effluent. Environ. Toxicol. Chem., 15: 1844-1854 .

LEBLANC, J., C.M. COUILLARD, 1995. Description de la période de reproduction d'un poisson sentinelle : le choquemort (Fundulus heteroclitus) de l'estuaire de la Miramichi. Rapp. tech. can. sci. halieut. aquat., 2057, 39 p .

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Knowledge of the reproductive period of the mummichog (Fundulus heteroclitus) in the Miramichi Estuary is required for planning ecotoxicological studies to evaluate the effects of contaminants on fish health and reproduction. The reproductive cycle of a population of mummichogs in the Miramichi Estuary was described by measuring weekly, from May to August 1993, variations in gonadosomatic index, gonadal maturity stage, proportion of females with mature eggs, fecundity, and plasmatic concentrations of estradiol and testosterone. The spawning period lasted 9 weeks approximatively, from the end of May to the end of July, and was discontinuous with 4 spawning peaks. Individuals fecundity per spawning act was estimated to be more than 200 eggs and the linear relationship between fecundity and female length was established. Variations of condition factor and hepatosomatic index of fish were described.

GILBERT, M., C.M. COUILLARD, 1995. Observations de mortalités de sébastes (Sebastes sp.) dans la région de la baie des Ha!Ha!, fjord du Saguenay : examen des causes possibles. Rapp. manus. can. sci. halieut. aquat., 2278, 15 p .

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In 1993 and 1994, redfish mortalities were reported on five occasions between July and October in the area of Baie des Ha! Ha!, in the Saguenay Fjord. The similar circumstances in which all these mortalities occurred indicate that they are related to a single cause. Low concentrations of heavy metals and organochlorines in tissues of individuals examined indicate that a long term bioaccumulation of contaminants is unlikely to have caused the observed mortalities. Mortalities resulting from epizootics, dismissed fisheries catches, or an acute intoxication caused by the presence of pollutants or toxic phytoplanktonic algae are all possible, although the observed events are not typical of such mortality causes. All mortalities were observed during the same phase of the tidal cycle, indicating a possible link with physicochemical and hydrodynamic conditions in the area of baie des Ha! Ha!. Redfish mortalities thus could have resulted from an anoxic, osmotic or thermal stress caused by increased local water mass movements during spring tides. Unusually cold summer conditions in the deep water mass of the baie des Ha! Ha! area, following particularly severe winters in 1993 and 1994, then would have induced the observed mortalities. However, additional information on the environmental conditions in which redfish mortalities occur, the characteristics and health status of affected individuals, as well as on the tolerance and acclimation limits of redfish to low temperature, is needed in order to determine with certainty their exact cause of mortality.

COUILLARD, C., P.V. HODSON, P. GAGNON, J.J. DODSON, 1995. Lesions and parasites in white suckers, Catostomus commersoni, in bleached-kraft pulp mill-contaminated and reference rivers. Environ. Toxicol. Chem., 14: 1051-1060 .

SÉVIGNY, J.-M., C.M. COUILLARD, 1994. Le fjord du Saguenay : un milieu exceptionnel de recherche. Rapp. manus. can. sci. halieut. aquat., 2270, 118 p .

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The objectives of the symposium were to bring up-to-date scientific knowledge related to the Saguenay fjord and to point out the main fields where research should be pursued in order to improve understanding of this environment. An additional objective of this symposium was to provide a forum to describe and discuss the marine park development project.

HODSON, P.V., E. PELLETIER, R. McLEOD, J. HELLOU, B. SAINTE-MARIE, C.M. COUILLARD, J.-M. SÉVIGNY, 1994. Chemical contamination of surface sediments and biota of the Saguenay Fjord. Pages 97-104 in J.-M. Sévigny & C.M. Couillard (éd.). Le fjord du Saguenay : un milieu exceptionnel de recherche. Ministère des pêches et des océans (Rapp. manus. can. sci. halieut. aquat., 2270) .

HODSON, P.V., M. CASTONGUAY, C.M. COUILLARD, C. DESJARDINS, E. PELLETIER, R. McLEOD, 1994. Spatial and temporal variations in chemical contamination of American eels, Anguilla rostrata, captured in the estuary of the St. Lawrence River. Can. J. Fish. Aquat. Sci., 51: 464-478 .

CASTONGUAY, M., P.V. HODSON, C.M. COUILLARD, M.J. ECKERSLEY, J.-D. DUTIL, G. VERREAULT, 1994. Why is recruitment of the American eel, Anguilla rostrata, declining in the St. Lawrence River and Gulf. Can. J. Fish. Aquat. Sci., 51: 479-488 .

COUILLARD, C.M., F.A. LEIGHTON, 1993. In vitro red blood cell essay for oxidant toxicity of petroleum oil. Environ. Toxicol. Chem., 12: 839-845 .

DUTIL, L., C.M. COUILLARD, D. THIVIERGE, 1992. Revue des observations pathologiques rapportées chez les poissons du Saint-Laurent et de ses principaux tributaires. Plan d'Action Saint-Laurent, Centre Saint-Laurent, 98 p .

HODSON, P.V., C. DESJARDINS, É. PELLETIER, M. CASTONGUAY, R. McLEOD, C.M. COUILLARD, 1992. Decrease in chemical contamination of American eels (Anguilla rostrata) captured in the Estuary of the St. Lawrence River. Can. Tech. Rep. Fish. Aquat. Sci., 1876, 57 p .

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American eels, Anguilla rostrata, are catadromous, and grow to maturity in Lake Ontario and in tributaries to the St. Lawrence River. Concern for mass mortalities of adult eels, high levels of chemical contamination, and a recent decline of recruitment prompted a study of the role of contaminants in the health of eels, the role of eels as vectors of contaminants to Beluga whales (Delphinapterus leucas) and the changes in contamination since an earlier large scale survey in 1982. Mercury, PCB, mirex and pesticide levels were measured in migratory adult eels in Kamouraska, Québec. Similar analyses were conducted on two eel samples from fishermen in Cacouna and Saint-Irénée, and on a control eel sample from a small tributary of the north shore of the St. Lawrence Estuary. Dioxins, furans and PAH concentrations were also determined on a small number of fish. Results indicate that eels from the upper St. Lawrence River/Lake Ontario were much more contaminated with PCBs, mirex and pesticides than the control population; concentrations did not vary among sites on the St. Lawrence River. Levels of PCBs and mirex have declined by 68 and 56 % respectively since 1982. Only 36 % of eels analyzed exceeded the guidelines for PCBs in fish, compared to 80 % in 1982; for mirex, the percentage declined from 52 % in 1982 to 29 % in 1990. Levels of PCBs, mirex and pesticides varied among weeks with a slight trend of increasing concentrations towards the end of the migration. Concentrations of PAH, dioxins and furans were usually less than their detection limits, and well below any guidelines. These results suggest that the risk of organic chemical toxicity to Belugas from consuming eels is declining from year to year. Mercury levels were constant among sites and times, indicating that accumulation originates mostly from natural sources or atmospheric deposition.

COUILLARD, C.M., S. LECLERC, H. GILBERT, M. GRENIER, C. MITCHELL, 1992. Localisation des principaux obstacles à la migration des anguilles le long du fleuve Saint-Laurent. Plan d'Action Saint-Laurent, Ministère des pêches et des océans, 28 p .

HODSON, P.V., D. BUISSIÈRES, M.M. GAGNON, J.J. DODSON, C.M. COUILLARD, J.C. CAREY, 1992. Review of biochemical, physiological, pathological and population responses of white sucker (Catostomus commersoni) to BKME in the St. Maurice River, Quebec. Pages 261-269 in A. Sodergren (ed.). Environmental fate and effects of bleached pulp mill effluents : proceedings of the International Conference, Stockholm, November, 1991 (Swedish EPA Report 4031) .

HODSON, P.V., C. DESJARDINS, É. PELLETIER, M. CASTONGUAY, R. McLEOD, C.M. COUILLARD, 1992. Baisse de la pollution chimique des anguilles d'Amérique (Anguilla rostrata) capturées dans l'estuaire du Saint-Laurent. Rapp. tech. can. sci. halieut. aquat., 1876, 60 p .

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American eels, Anguilla rostrata, are catadromous, and grow to maturity in Lake Ontario and in tributaries to the St. Lawrence River. Concern for mass mortalities of adult eels, high levels of chemical contamination, and a recent decline of recruitment prompted a study of the role of contaminants in the health of eels, the role of eels as vectors of contaminants to Beluga whales (Delphinapterus leucas) and the changes in contamination since an earlier large scale survey in 1982. Mercury, PCB, mirex and pesticide levels were measured in migratory adult eels in Kamouraska, Québec. Similar analyses were conducted on two eel samples from fishermen in Cacouna and Saint-Irénée, and on a control eel sample from a small tributary of the north shore of the St. Lawrence Estuary. Dioxins, furans and PAH concentrations were also determined on a small number of fish. Results indicate that eels from the upper St. Lawrence River/Lake Ontario were much more contaminated with PCBs, mirex and pesticides than the control population; concentrations did not vary among sites on the St. Lawrence River. Levels of PCBs and mirex have declined by 68 and 56 % respectively since 1982. Only 36 % of eels analyzed exceeded the guidelines for PCBs in fish, compared to 80 % in 1982; for mirex, the percentage declined from 52 % in 1982 to 29 % in 1990. Levels of PCBs, mirex and pesticides varied among weeks with a slight trend of increasing concentrations towards the end of the migration. Concentrations of PAH, dioxins and furans were usually less than their detection limits, and well below any guidelines. These results suggest that the risk of organic chemical toxicity to Belugas from consuming eels is declining from year to year. Mercury levels were constant among sites and times, indicating that accumulation originates mostly from natural sources or atmospheric deposition.

COUILLARD, C.M., F.A. LEIGHTON, 1991. Critical period of sensitivity to petroleum toxicity in the chicken embryo. Environ. Toxicol. Chem., 10: 249-253 .

COUILLARD, C.M., F.A. LEIGHTON, 1991. Bioassays for the toxicity of petroleum oils in chicken embryos. Environ. Toxicol. Chem., 10: 533-538 .