Jonathan Verreault | Université du Québec à Montréal (original) (raw)

Papers by Jonathan Verreault

Research paper thumbnail of Field Metabolic Rate Is Dependent on Time-Activity Budget in Ring-Billed Gulls (Larus delawarensis) Breeding in an Anthropogenic Environment

PLOS ONE, 2015

Environmental and behavioral factors have long been assumed to affect variation in avian field me... more Environmental and behavioral factors have long been assumed to affect variation in avian field metabolic rate (FMR). However, due to the difficulties in measuring continuous behavior of birds over prolonged periods of time, complete time-activity budgets have rarely been examined in relation to FMR. Our objective was to determine the effect of activity (measured by detailed time-activity budgets) and a series of extrinsic and intrinsic factors on FMR of the omnivorous ring-billed gull (Larus delawarensis). The experiment was conducted during the incubation period when both members of the pair alternate between attending the nest-site and leaving the colony to forage in aquatic and anthropogenic environments (city, agricultural). FMR was determined using the doubly labeled water method. Time-activity budgets were extrapolated from spatio-temporal data (2-5 days) obtained from bird-borne GPS data loggers. Gulls had low FMRs compared to those predicted by allometric equations based on recorded FMRs from several seabird species. Gulls proportioned their time mainly to nest-site attendance (71% of total tracking time), which reduced FMR/g body mass, and was the best variable explaining energy expenditure. The next best variable was the duration of foraging trips, which increased FMR/g; FMR/g was also elevated by the proportion of time spent foraging or flying (17% and 8% of tracking time respectively). Most environmental variables measured did not impact FMR/g, however, the percent of time birds were subjected to temperatures below their lower critical temperature increased FMR. Time-activity budgets varied between the sexes, and with temperature and capture date suggesting that these variables indirectly affected FMR/g. The gulls foraged preferentially in anthropogenic-related habitats, which may have contributed to their low FMR/g due to the high availability of protein-and lipid-rich foods. This study demonstrates that activities were the best predictors of FMR/g in ring-billed gulls, thus providing strong support for this long-standing theory in bioenergetics.

Research paper thumbnail of Composition of chlorinated hydrocarbon contaminants among major adipose tissue depots of polar bears (Ursus maritimus) from the Canadian high Arctic

The Science of the total environment, 2006

Monitoring of environmental contaminants in Canadian Arctic polar bears (Ursus maritimus) typical... more Monitoring of environmental contaminants in Canadian Arctic polar bears (Ursus maritimus) typically has used superficial adipose tissue samples collected as part of controlled native subsistence hunts. However, little attention has been paid to the compositional difference in contaminants that may exist among the major adipose depots that are routinely collected. To address this knowledge gap, we investigated the profiles and concentrations of chlorinated hydrocarbon contaminants (CHCs), including major polychlorinated biphenyl (PCB) congeners and organochlorine (OC) pesticides and metabolites, in six major adipose depots (i.e. superficial, inter-muscular and intra-abdominal regions) obtained from adult male polar bears in the vicinity of Resolute Bay, Canadian high Arctic. Concentrations and congener patterns of PCBs (20 congeners) and OCs (14 compounds; chlordanes and dichlorodiphenyltrichloroethanes and metabolites, chlorinated benzenes, hexachlorocyclohexane isomers, octachloros...

Research paper thumbnail of Organohalogen contamination in breeding glaucous gulls from the Norwegian Arctic: Associations with basal metabolism and circulating thyroid hormones

Basal metabolic rate in glaucous gulls was negatively associated with plasma organochlorine conce... more Basal metabolic rate in glaucous gulls was negatively associated with plasma organochlorine concentrations, but not with circulating thyroid hormone levels.

Research paper thumbnail of Chlorinated hydrocarbon contaminants and metabolites in polar bears (Ursus maritimus) from Alaska, Canada, East Greenland, and Svalbard: 1996−2002

Science of The Total Environment, 2005

A suite of chlorinated hydrocarbon contaminants (CHCs) including organochlorine pesticides (OCPs)... more A suite of chlorinated hydrocarbon contaminants (CHCs) including organochlorine pesticides (OCPs) and by-products, polychlorinated biphenyls (PCBs), and methyl sulfone (MeSO 2 ) PCB and p,pV-dichlorodiphenyldichloroethylene ( p,pV-DDE) metabolites were determined in adipose tissue of 107 adult and sub-adult polar bears, almost exclusively females, sampled between 1996 and 2002 from populations spanning Arctic and Subarctic regions of Alaska, Canada, East Greenland, and Svalbard. The East Greenland and Svalbard populations of polar bears were distinguished by higher proportions of dichlorodiphenyldichloroethane (DDT)-related compounds, nonachlors, oxychlordane, and higher-chlorinated and persistent PCB 0048-9697/$ -see front matter. Crown Science of the Total Environment 351-352 (2005) 369 -390

Research paper thumbnail of Exposure and effects assessment of persistent organohalogen contaminants in arctic wildlife and fish

Science of The Total Environment, 2010

Persistent organic pollutants (POPs) encompass an array of anthropogenic organic and elemental su... more Persistent organic pollutants (POPs) encompass an array of anthropogenic organic and elemental substances and their degradation and metabolic byproducts that have been found in the tissues of exposed animals, especially POPs categorized as organohalogen contaminants (OHCs). OHCs have been of concern in the circumpolar arctic for decades. For example, as a consequence of bioaccumulation and in some cases biomagnification of legacy (e.g., chlorinated PCBs, DDTs and CHLs) and emerging (e.g., brominated flame retardants (BFRs) and in particular polybrominated diphenyl ethers (PBDEs) and perfluorinated compounds (PFCs) including perfluorooctane sulfonate (PFOS) and perfluorooctanic acid (PFOA) found in Arctic biota and humans. Of high concern are the potential biological effects of these contaminants in exposed Arctic wildlife and fish. As concluded in the last review in 2004 for the Arctic Monitoring and Assessment Program (AMAP) on the effects of POPs in Arctic wildlife, prior to 1997, biological effects data were minimal and insufficient at any level of biological organization. The present review summarizes recent studies on biological effects in relation to OHC exposure, and attempts to assess known tissue/body compartment concentration data in the context of possible threshold levels of effects to evaluate the risks. This review concentrates mainly on post-2002, new OHC effects data in Arctic wildlife and fish, and is largely based on recently available effects data for populations of several top trophic level species, including seabirds (e.g., glaucous gull (Larus hyperboreus)), polar bears (Ursus maritimus), polar (Arctic) fox (Vulpes lagopus), and Arctic charr (Salvelinus alpinus), as well as semi-captive studies on sled dogs (Canis familiaris). Regardless, there remains a dearth of data on true contaminant exposure, cause-effect relationships with respect to these contaminant exposures in Arctic wildlife and fish. Indications of exposure effects are largely based on correlations between biomarker endpoints (e.g., biochemical processes related to the immune and endocrine

Research paper thumbnail of Relationship between persistent halogenated organic contaminants and TCDD-toxic equivalents on EROD activity and retinoid and thyroid hormone status in northern fulmars

Science of The Total Environment, 2010

Arctic seabirds are exposed to a wide range of halogenated organic contaminants (HOCs). Exposure ... more Arctic seabirds are exposed to a wide range of halogenated organic contaminants (HOCs). Exposure occurs mainly through food intake, and many pollutants accumulate in lipid-rich tissues. Little is known about how HOCs are biotransformed in arctic seabirds. In this study, we characterized biotransformation enzymes in chicks of northern fulmars (Fulmarus glacialis) and black-legged kittiwakes (Rissa tridactyla) from Kongsfjorden (Svalbard, Norway). Phase I and II enzymes were analyzed at the transcriptional, translational and activity levels. For gene expression patterns, quantitative polymerase chain reactions (qPCR), using gene-sequence primers, were performed. Protein levels were analyzed using immunochemical assays of western blot with commercially available antibodies. Liver samples were analyzed for phase I and II enzyme activities using a variety of substrates including ethoxyresorufin (cytochrome (CYP)1A1/1A2), pentoxyresorufin (CYP2B), methoxyresorufin (CYP1A), benzyloxyresorufin (CYP3A), testosterone (CYP3A/CYP2B), 1chloro-2,4-nitrobenzene (CDNB) (glutathione S-transferase (GST)) and 4-nitrophenol (uridine diphosphate glucuronyltransferase (UDPGT)). In addition, the hydroxylated (OH-) polychlorinated biphenyls (PCBs) were analyzed in the blood, liver and brain tissue, whereas the methylsulfone (MeSO 2 -) PCBs were analyzed in liver tissue. Results indicated the presence of phase I (CYP1A4/CYP1A5, CYP2B, and CYP3A) and phase II (GST and UDPGT) enzymes at the activity, protein and/or mRNA level in both species. Northern fulmar chicks had higher enzyme activity than black-legged kittiwake chicks. This in combination with the higher ΣOH-PCB to parent PCB ratios suggests that northern fulmar chicks have a different biotransformation capacity than black-legged kittiwake chicks.

Research paper thumbnail of Validation of Water Flux and Body Composition in Glaucous Gulls ( Larus hyperboreus )

Physiological and Biochemical Zoology, 2006

Water influx rates (WIR) measured with tritiated water dilution were compared with direct measure... more Water influx rates (WIR) measured with tritiated water dilution were compared with direct measures of water and energy intake in glaucous gulls (Larus hyperboreus). Total body water (TBW) measured isotopically was also compared with TBW determined by body composition analysis (BCA) of the same birds. Seventeen wild gulls were captured and studied in outdoor enclosures at Ny-Å lesund, Svalbard, in July 2002. Gulls were hand-fed known quantities of Arctic cod (Boreogadus saida) or given water on the basis of one of four experimental treatments: (A) fasting, (B) fish only, (C) water only, or (D) fish and water. Water and energy content of Arctic cod was also determined. WIR of gulls (after subtracting metabolic water production) in treatments A, B, C, and D were 0, , , and 101 ‫ע‬ 5 ‫ע26‬ 19 SD g d Ϫ1 , respectively. Measured water intake in each 122 ‫ע‬ 21 group was 0, , , and SD g d Ϫ1 , respec-111 ‫ע‬ 2 64 ‫ע‬ 3 ‫ע431‬ 15 tively. On average, WIR underestimated measured water intake in each group. Errors were lowest but most variable for gulls fed water only ( ) compared with gulls fed fish Ϫ2.2% ‫ע‬ 32.8% only ( ) or fish and water ( ). Ϫ9.0% ‫ע‬ 5.4%

Research paper thumbnail of Changes in prolactin in a highly organohalogen contaminated Arctic top predator seabird, the glaucous gull

General and Comparative Endocrinology, 2008

The factors influencing prolactin (PRL) variation in birds and in wildlife in general have rarely... more The factors influencing prolactin (PRL) variation in birds and in wildlife in general have rarely been investigated with respect to the physiological impacts of exposure to environmental contaminants. We investigated the associations between circulating baseline PRL levels and concentrations of eight persistent organohalogen contaminant (OHC) classes (i.e., major organochlorines and brominated flame retardants, and associated metabolic products) in blood (plasma) of free-ranging glaucous gulls (Larus hyperboreus), a top predator in the Norwegian Arctic, engaged in the process of incubation. We further examined whether plasma OHC concentrations were associated with the variation of PRL in glaucous gulls exposed to a standardized capture/restraint protocol. Plasma OHC concentrations in male glaucous gulls were 2to 3-fold higher relative to females. Baseline PRL levels tended to be higher in females compared to males, although not significantly (p = 0.20). In both males and females, the 30-min capture/restraint protocol led on average to a 26% decrease in PRL levels, which resulted in a rate of PRL decrease of 0.76 ng/mL/min. The baseline PRL levels and the rate of decrease in PRL levels tended to vary negatively with plasma OHC concentrations in males, but not in females, although several of these associations did not adhere with the criterion of significance (a = 0.05). Present results suggest that in highly OHC-exposed male glaucous gulls, the control of PRL release may be affected by the direct or indirect modulating actions of OHCs and/or their metabolically derived products. We conclude that potentially OHC-mediated impact on PRL secretion in glaucous gulls (males) may be a contributing factor to the adverse effects observed on the reproductive behavior, development and population size of glaucous gulls breeding in the Norwegian Arctic.

Research paper thumbnail of ORGANOHALOGEN CONTAMINANTS AND REPRODUCTIVE HORMONES IN INCUBATING GLAUCOUS GULLS (LARUS HYPERBOREUS) FROM THE NORWEGIAN ARCTIC

Environmental Toxicology and Chemistry, 2006

Research paper thumbnail of NEW ORGANOCHLORINE CONTAMINANTS AND METABOLITES IN PLASMA AND EGGS OF GLAUCOUS GULLS (LARUS HYPERBOREUS) FROM THE NORWEGIAN ARCTIC

Environmental Toxicology and Chemistry, 2005

Research paper thumbnail of COMPARATIVE HEPATIC ACTIVITY OF XENOBIOTIC-METABOLIZING ENZYMES AND CONCENTRATIONS OF ORGANOHALOGENS AND THEIR HYDROXYLATED ANALOGUES IN CAPTIVE GREENLAND SLEDGE DOGS (CANIS FAMILIARIS)

Environmental Toxicology and Chemistry, 2009

A captive study was performed with Greenland sledge dogs (Canis familiaris) fed a naturally organ... more A captive study was performed with Greenland sledge dogs (Canis familiaris) fed a naturally organohalogen-contaminated diet (Greenland minke whale [Balaenoptera acutorostrata] blubber; exposed group) or a control diet (pork fat; control group). The catalytic activity of major xenobiotic-metabolizing phase I and II hepatic microsomal enzymes was assessed. Relative to control dogs, ethoxyresorufin-O-deethylase (EROD) activity in exposed dogs was twofold higher ( p ϭ 0.001). Testosterone hydroxylation yielded 6␤-and 16␤-hydroxy (OH) testosterone and androstenedione, with higher rates of production (23-27%; p Յ 0.03) in the exposed individuals. In the exposed dogs, epoxide hydrolase (EH) activity was 31% higher ( p ϭ 0.02) relative to the control dogs, whereas uridine diphosphoglucuronosyl transferase (UDPGT) activity was not different ( p ϭ 0.62). When the exposed and control dogs were combined, the summed (⌺) plasma concentrations of OH-polychlorinated biphenyl (PCB) congeners were predicted by plasma ⌺PCB concentrations and EROD activity ( p Յ 0.04), whereas testosterone hydroxylase, EH, and UDPGT activities were not significant predictors of these concentrations. Consistent results were found for individual OH-PCB congeners and their theoretical precursor PCBs (e.g., 4-OH-CB-187 and CB-183, and 4-OH-CB-146 and CB-146) and for EROD activity. No association was found between ⌺OH-polybrominated diphenyl ether (PBDE) and ⌺PBDE plasma concentrations, or between potential precursor-metabolite pairs, and the enzyme activities. The present results suggest that liver microsomal EROD activity and plasma PCB concentrations have a greater (e.g., relative to EH activity) predictive power for the occurrence of plasma OH-PCB residues in sledge dogs. These results also suggest that plasma OH-PBDEs likely are not products of cytochrome P450mediated transformation but, rather, are accumulated via the diet.

Research paper thumbnail of Trends of Perfluorinated Alkyl Substances in Herring Gull Eggs from Two Coastal Colonies in Northern Norway:  1983−2003

Environmental Science & Technology, 2007

Research paper thumbnail of Brominated Flame Retardants in Glaucous Gulls from the Norwegian Arctic:  More Than Just an Issue of Polybrominated Diphenyl Ethers

Environmental Science & Technology, 2007

Several, unregulated, current-use brominated flame retardants (BFRs), including hexabromobenzene ... more Several, unregulated, current-use brominated flame retardants (BFRs), including hexabromobenzene (HBB), 1,2bis(2,4,6-tribromophenoxy)ethane (BTBPE), pentabromoethylbenzene (PBEB), pentabromotoluene (PBT), and hexabromocyclododecane (as total-(R)-HBCD), were examined in egg yolk and plasma of male and female glaucous gulls (Larus hyperboreus) from the Norwegian Arctic. Also examined were BDE209 and 38 tri-to nona-BDE congeners and brominated biphenyl (BB) 101. The HBB, BTBPE, PBEB, and PBT had high detection frequencies and variability in male and female plasma and egg yolk samples, and their concentrations ranged from nondetectable (<0.02-0.27 ng/g wet wt) to 2.64 ng/g wet wt. The detection frequencies and range of concentrations of non-BDE BFRs were generally highest in plasma of males relative to females. Total-(R)-HBCD concentrations were highest among the non-PBDE BFRs (up to 6.12 and 63.9 ng/g wet wt in plasma and egg yolk, respectively). Next highest was HBB with concentrations within a range comparable to the minor PBDEs monitored (e.g., BDE28, 116 and 155). Sum (Σ) 38 PBDE concentrations ranged from 2.49 to 54.5 ng/g wet wt in plasma and 81.2 to 321 ng/g wet wt in egg yolk. The BDE209 was virtually nondetectable, whereas six octa-BDEs (i.e., BDE196, 197, 201, 202, 203, and 205), as well as three nona-BDEs (i.e., BDE206, 207, and 208, and potential BDE209 debromination products) were found sporadically in plasma and egg yolk. The results from this study suggest that in addition to PBDEs, several currentuse, non-BDE BFRs undergo long-range atmospheric transport and bioaccumulate at low levels in and are maternally transferred (to eggs) in glaucous gulls from the Norwegian Arctic.

Research paper thumbnail of Perfluorinated Alkyl Substances in Plasma, Liver, Brain, and Eggs of Glaucous Gulls ( Larus hyperboreus ) from the Norwegian Arctic

Environmental Science & Technology, 2005

1. Jones, P. D.; Hu, W.; de Coen, W.; Newsted, J. L.; Giesy, J. P. Environ. Toxicol. Chem. 2003, ... more 1. Jones, P. D.; Hu, W.; de Coen, W.; Newsted, J. L.; Giesy, J. P. Environ. Toxicol. Chem. 2003, 22, 2639-2649. 2. Newsted, J. L.; Coady, K. K.; Beach, S. A.; Butenhoff, J. L.; Gallagher, S.; Giesy, J. P. Environ. Toxicol. Pharmacol., submitted. 3. Hansen, K. J.; Clemen, L. A.; Ellefson, M. E.; Johnson, H. O. Environ. Sci. Technol. 2001, 35, 766-770. 4. Berger, U.; Haukås, M. J. Chrom. A., in press.

Research paper thumbnail of Flame Retardants and Methoxylated and Hydroxylated Polybrominated Diphenyl Ethers in Two Norwegian Arctic Top Predators:  Glaucous Gulls and Polar Bears

Environmental Science & Technology, 2005

Research paper thumbnail of Maternal transfer of organohalogen contaminants and metabolites to eggs of Arctic-breeding glaucous gulls

Environmental Pollution, 2006

with the laying order in a three-egg clutch.

Research paper thumbnail of Organohalogen contamination in breeding glaucous gulls from the Norwegian Arctic: Associations with basal metabolism and circulating thyroid hormones

Environmental Pollution, 2007

Basal metabolic rate in glaucous gulls was negatively associated with plasma organochlorine conce... more Basal metabolic rate in glaucous gulls was negatively associated with plasma organochlorine concentrations, but not with circulating thyroid hormone levels.

Research paper thumbnail of Halogenated organic contaminants and mercury in northern fulmars (Fulmarus glacialis): levels, relationships to dietary descriptors and blood to liver comparison

Environmental Pollution, 2007

Halogenated organic contaminants and mercury in northern fulmars (Fulmarus glacialis): levels, re... more Halogenated organic contaminants and mercury in northern fulmars (Fulmarus glacialis): levels, relationships to dietary descriptors and blood to liver comparison Partial dioxin-like toxicity in northern fulmars based on toxic equivalents (TEQs) was well above thresholds for reproductive effects in seabirds.

Research paper thumbnail of Effects of Organochlorine Contaminants on Thyroid Hormone Levels in Arctic Breeding Glaucous Gulls, Larus hyperboreus

Environmental Health Perspectives, 2003

Studies on glaucous gulls (Larus hyperboreus) breeding in the Barents Sea have reported that high... more Studies on glaucous gulls (Larus hyperboreus) breeding in the Barents Sea have reported that high blood levels of halogenated organic contaminants in this species might cause reproductive, behavioral, and developmental stress. However, potential endocrine system modulation caused by contaminant exposure has yet not been reported in this Arctic apical predator. In this present study we aimed to investigate whether the current levels of a selection of organochlorines (OCs) were associated with altered circulating levels of thyroid hormones (THs) in free-ranging adult glaucous gulls breeding at Bear Island in the Barents Sea. Blood concentrations of 14 polychlorinated biphenyls, hexachlorobenzene (HCB), oxychlordane, and p,p´-dichlorodiphenyldichloroethylene (p,p´-DDE) were quantified, in addition to free and total thyroxine (T 4 ) and triiodothyronine (T 3 ), in plasma of 66 glaucous gulls in the spring of 2001. Negative correlations were found between plasma levels of T 4 and T 4 :T 3 ratio, and blood levels of OCs in male glaucous gulls. Despite their relatively low contribution to the total OC fraction, HCB and oxychlordane were the most prominent compounds in terms of their negative effect on the variation of the T 4 :T 3 ratio. Moreover, lower T 4 levels and T 4 :T 3 ratios were measured in glaucous gulls breeding in a colony exposed to high levels of OCs, compared with a less exposed colony. Levels of T 3 were elevated in the high-OC-exposed colony. This may indicate that the glaucous gull is susceptible to changes to TH homeostasis mediated by exposure to halogenated organic contaminants.

Research paper thumbnail of Comparative fate of organohalogen contaminants in two top carnivores in Greenland: Captive sledge dogs and wild polar bears

Comparative Biochemistry and Physiology Part C: Toxicology & Pharmacology, 2008

The limited knowledge and/or the inability to control physiological condition parameters that inf... more The limited knowledge and/or the inability to control physiological condition parameters that influence the fate of organohalogen contaminants (OHCs) has been the foremost confounding aspect in monitoring programs and health risk assessments of wild top predators in the Arctic such as the polar bear (Ursus maritimus). In the present comparative study, we used a potential surrogate Canoidea species for the East Greenland polar bear, the captive sledge dog (Canis familiaris), to investigate some factors that may influence the bioaccumulation and biotransformation of major chlorinated and brominated OHCs in adipose tissue and blood (plasma) of control (fed commercial pork fat) and exposed (fed West Greenland minke whale (Balaenoptera acutorostrata) blubber) adult female sledge dogs. Furthermore, we compared the patterns and concentrations of OHCs and their known or suggested hydroxylated (OH) metabolites (e.g., OH-PCBs) in sledge dogs with those in adipose tissue and blood (plasma) of East Greenland adult female polar bears, and blubber of their main prey species, the ringed seal (Pusa hispida). The two-year feeding regime conducted with sledge dogs led to marked differences in overall adipose tissue (and plasma) OHC residue accumulation between the control and exposed groups. Characteristic prey-to-predator OHC bioaccumulation dynamics for major PCB and PBDE congeners (patterns and concentrations) and biotransformation capacity with respect to PCB metabolite formation and OH-PCB retention distinguished, to some extent, captive sledge dogs and wild polar bears. Based on the present findings, we conclude that the use of surrogate species in toxicological investigations for species in the Canoidea family should be done with great caution, although they remain essential in the context of contaminants research with sensitive arctic top carnivore species such as the polar bear.

Research paper thumbnail of Field Metabolic Rate Is Dependent on Time-Activity Budget in Ring-Billed Gulls (Larus delawarensis) Breeding in an Anthropogenic Environment

PLOS ONE, 2015

Environmental and behavioral factors have long been assumed to affect variation in avian field me... more Environmental and behavioral factors have long been assumed to affect variation in avian field metabolic rate (FMR). However, due to the difficulties in measuring continuous behavior of birds over prolonged periods of time, complete time-activity budgets have rarely been examined in relation to FMR. Our objective was to determine the effect of activity (measured by detailed time-activity budgets) and a series of extrinsic and intrinsic factors on FMR of the omnivorous ring-billed gull (Larus delawarensis). The experiment was conducted during the incubation period when both members of the pair alternate between attending the nest-site and leaving the colony to forage in aquatic and anthropogenic environments (city, agricultural). FMR was determined using the doubly labeled water method. Time-activity budgets were extrapolated from spatio-temporal data (2-5 days) obtained from bird-borne GPS data loggers. Gulls had low FMRs compared to those predicted by allometric equations based on recorded FMRs from several seabird species. Gulls proportioned their time mainly to nest-site attendance (71% of total tracking time), which reduced FMR/g body mass, and was the best variable explaining energy expenditure. The next best variable was the duration of foraging trips, which increased FMR/g; FMR/g was also elevated by the proportion of time spent foraging or flying (17% and 8% of tracking time respectively). Most environmental variables measured did not impact FMR/g, however, the percent of time birds were subjected to temperatures below their lower critical temperature increased FMR. Time-activity budgets varied between the sexes, and with temperature and capture date suggesting that these variables indirectly affected FMR/g. The gulls foraged preferentially in anthropogenic-related habitats, which may have contributed to their low FMR/g due to the high availability of protein-and lipid-rich foods. This study demonstrates that activities were the best predictors of FMR/g in ring-billed gulls, thus providing strong support for this long-standing theory in bioenergetics.

Research paper thumbnail of Composition of chlorinated hydrocarbon contaminants among major adipose tissue depots of polar bears (Ursus maritimus) from the Canadian high Arctic

The Science of the total environment, 2006

Monitoring of environmental contaminants in Canadian Arctic polar bears (Ursus maritimus) typical... more Monitoring of environmental contaminants in Canadian Arctic polar bears (Ursus maritimus) typically has used superficial adipose tissue samples collected as part of controlled native subsistence hunts. However, little attention has been paid to the compositional difference in contaminants that may exist among the major adipose depots that are routinely collected. To address this knowledge gap, we investigated the profiles and concentrations of chlorinated hydrocarbon contaminants (CHCs), including major polychlorinated biphenyl (PCB) congeners and organochlorine (OC) pesticides and metabolites, in six major adipose depots (i.e. superficial, inter-muscular and intra-abdominal regions) obtained from adult male polar bears in the vicinity of Resolute Bay, Canadian high Arctic. Concentrations and congener patterns of PCBs (20 congeners) and OCs (14 compounds; chlordanes and dichlorodiphenyltrichloroethanes and metabolites, chlorinated benzenes, hexachlorocyclohexane isomers, octachloros...

Research paper thumbnail of Organohalogen contamination in breeding glaucous gulls from the Norwegian Arctic: Associations with basal metabolism and circulating thyroid hormones

Basal metabolic rate in glaucous gulls was negatively associated with plasma organochlorine conce... more Basal metabolic rate in glaucous gulls was negatively associated with plasma organochlorine concentrations, but not with circulating thyroid hormone levels.

Research paper thumbnail of Chlorinated hydrocarbon contaminants and metabolites in polar bears (Ursus maritimus) from Alaska, Canada, East Greenland, and Svalbard: 1996−2002

Science of The Total Environment, 2005

A suite of chlorinated hydrocarbon contaminants (CHCs) including organochlorine pesticides (OCPs)... more A suite of chlorinated hydrocarbon contaminants (CHCs) including organochlorine pesticides (OCPs) and by-products, polychlorinated biphenyls (PCBs), and methyl sulfone (MeSO 2 ) PCB and p,pV-dichlorodiphenyldichloroethylene ( p,pV-DDE) metabolites were determined in adipose tissue of 107 adult and sub-adult polar bears, almost exclusively females, sampled between 1996 and 2002 from populations spanning Arctic and Subarctic regions of Alaska, Canada, East Greenland, and Svalbard. The East Greenland and Svalbard populations of polar bears were distinguished by higher proportions of dichlorodiphenyldichloroethane (DDT)-related compounds, nonachlors, oxychlordane, and higher-chlorinated and persistent PCB 0048-9697/$ -see front matter. Crown Science of the Total Environment 351-352 (2005) 369 -390

Research paper thumbnail of Exposure and effects assessment of persistent organohalogen contaminants in arctic wildlife and fish

Science of The Total Environment, 2010

Persistent organic pollutants (POPs) encompass an array of anthropogenic organic and elemental su... more Persistent organic pollutants (POPs) encompass an array of anthropogenic organic and elemental substances and their degradation and metabolic byproducts that have been found in the tissues of exposed animals, especially POPs categorized as organohalogen contaminants (OHCs). OHCs have been of concern in the circumpolar arctic for decades. For example, as a consequence of bioaccumulation and in some cases biomagnification of legacy (e.g., chlorinated PCBs, DDTs and CHLs) and emerging (e.g., brominated flame retardants (BFRs) and in particular polybrominated diphenyl ethers (PBDEs) and perfluorinated compounds (PFCs) including perfluorooctane sulfonate (PFOS) and perfluorooctanic acid (PFOA) found in Arctic biota and humans. Of high concern are the potential biological effects of these contaminants in exposed Arctic wildlife and fish. As concluded in the last review in 2004 for the Arctic Monitoring and Assessment Program (AMAP) on the effects of POPs in Arctic wildlife, prior to 1997, biological effects data were minimal and insufficient at any level of biological organization. The present review summarizes recent studies on biological effects in relation to OHC exposure, and attempts to assess known tissue/body compartment concentration data in the context of possible threshold levels of effects to evaluate the risks. This review concentrates mainly on post-2002, new OHC effects data in Arctic wildlife and fish, and is largely based on recently available effects data for populations of several top trophic level species, including seabirds (e.g., glaucous gull (Larus hyperboreus)), polar bears (Ursus maritimus), polar (Arctic) fox (Vulpes lagopus), and Arctic charr (Salvelinus alpinus), as well as semi-captive studies on sled dogs (Canis familiaris). Regardless, there remains a dearth of data on true contaminant exposure, cause-effect relationships with respect to these contaminant exposures in Arctic wildlife and fish. Indications of exposure effects are largely based on correlations between biomarker endpoints (e.g., biochemical processes related to the immune and endocrine

Research paper thumbnail of Relationship between persistent halogenated organic contaminants and TCDD-toxic equivalents on EROD activity and retinoid and thyroid hormone status in northern fulmars

Science of The Total Environment, 2010

Arctic seabirds are exposed to a wide range of halogenated organic contaminants (HOCs). Exposure ... more Arctic seabirds are exposed to a wide range of halogenated organic contaminants (HOCs). Exposure occurs mainly through food intake, and many pollutants accumulate in lipid-rich tissues. Little is known about how HOCs are biotransformed in arctic seabirds. In this study, we characterized biotransformation enzymes in chicks of northern fulmars (Fulmarus glacialis) and black-legged kittiwakes (Rissa tridactyla) from Kongsfjorden (Svalbard, Norway). Phase I and II enzymes were analyzed at the transcriptional, translational and activity levels. For gene expression patterns, quantitative polymerase chain reactions (qPCR), using gene-sequence primers, were performed. Protein levels were analyzed using immunochemical assays of western blot with commercially available antibodies. Liver samples were analyzed for phase I and II enzyme activities using a variety of substrates including ethoxyresorufin (cytochrome (CYP)1A1/1A2), pentoxyresorufin (CYP2B), methoxyresorufin (CYP1A), benzyloxyresorufin (CYP3A), testosterone (CYP3A/CYP2B), 1chloro-2,4-nitrobenzene (CDNB) (glutathione S-transferase (GST)) and 4-nitrophenol (uridine diphosphate glucuronyltransferase (UDPGT)). In addition, the hydroxylated (OH-) polychlorinated biphenyls (PCBs) were analyzed in the blood, liver and brain tissue, whereas the methylsulfone (MeSO 2 -) PCBs were analyzed in liver tissue. Results indicated the presence of phase I (CYP1A4/CYP1A5, CYP2B, and CYP3A) and phase II (GST and UDPGT) enzymes at the activity, protein and/or mRNA level in both species. Northern fulmar chicks had higher enzyme activity than black-legged kittiwake chicks. This in combination with the higher ΣOH-PCB to parent PCB ratios suggests that northern fulmar chicks have a different biotransformation capacity than black-legged kittiwake chicks.

Research paper thumbnail of Validation of Water Flux and Body Composition in Glaucous Gulls ( Larus hyperboreus )

Physiological and Biochemical Zoology, 2006

Water influx rates (WIR) measured with tritiated water dilution were compared with direct measure... more Water influx rates (WIR) measured with tritiated water dilution were compared with direct measures of water and energy intake in glaucous gulls (Larus hyperboreus). Total body water (TBW) measured isotopically was also compared with TBW determined by body composition analysis (BCA) of the same birds. Seventeen wild gulls were captured and studied in outdoor enclosures at Ny-Å lesund, Svalbard, in July 2002. Gulls were hand-fed known quantities of Arctic cod (Boreogadus saida) or given water on the basis of one of four experimental treatments: (A) fasting, (B) fish only, (C) water only, or (D) fish and water. Water and energy content of Arctic cod was also determined. WIR of gulls (after subtracting metabolic water production) in treatments A, B, C, and D were 0, , , and 101 ‫ע‬ 5 ‫ע26‬ 19 SD g d Ϫ1 , respectively. Measured water intake in each 122 ‫ע‬ 21 group was 0, , , and SD g d Ϫ1 , respec-111 ‫ע‬ 2 64 ‫ע‬ 3 ‫ע431‬ 15 tively. On average, WIR underestimated measured water intake in each group. Errors were lowest but most variable for gulls fed water only ( ) compared with gulls fed fish Ϫ2.2% ‫ע‬ 32.8% only ( ) or fish and water ( ). Ϫ9.0% ‫ע‬ 5.4%

Research paper thumbnail of Changes in prolactin in a highly organohalogen contaminated Arctic top predator seabird, the glaucous gull

General and Comparative Endocrinology, 2008

The factors influencing prolactin (PRL) variation in birds and in wildlife in general have rarely... more The factors influencing prolactin (PRL) variation in birds and in wildlife in general have rarely been investigated with respect to the physiological impacts of exposure to environmental contaminants. We investigated the associations between circulating baseline PRL levels and concentrations of eight persistent organohalogen contaminant (OHC) classes (i.e., major organochlorines and brominated flame retardants, and associated metabolic products) in blood (plasma) of free-ranging glaucous gulls (Larus hyperboreus), a top predator in the Norwegian Arctic, engaged in the process of incubation. We further examined whether plasma OHC concentrations were associated with the variation of PRL in glaucous gulls exposed to a standardized capture/restraint protocol. Plasma OHC concentrations in male glaucous gulls were 2to 3-fold higher relative to females. Baseline PRL levels tended to be higher in females compared to males, although not significantly (p = 0.20). In both males and females, the 30-min capture/restraint protocol led on average to a 26% decrease in PRL levels, which resulted in a rate of PRL decrease of 0.76 ng/mL/min. The baseline PRL levels and the rate of decrease in PRL levels tended to vary negatively with plasma OHC concentrations in males, but not in females, although several of these associations did not adhere with the criterion of significance (a = 0.05). Present results suggest that in highly OHC-exposed male glaucous gulls, the control of PRL release may be affected by the direct or indirect modulating actions of OHCs and/or their metabolically derived products. We conclude that potentially OHC-mediated impact on PRL secretion in glaucous gulls (males) may be a contributing factor to the adverse effects observed on the reproductive behavior, development and population size of glaucous gulls breeding in the Norwegian Arctic.

Research paper thumbnail of ORGANOHALOGEN CONTAMINANTS AND REPRODUCTIVE HORMONES IN INCUBATING GLAUCOUS GULLS (LARUS HYPERBOREUS) FROM THE NORWEGIAN ARCTIC

Environmental Toxicology and Chemistry, 2006

Research paper thumbnail of NEW ORGANOCHLORINE CONTAMINANTS AND METABOLITES IN PLASMA AND EGGS OF GLAUCOUS GULLS (LARUS HYPERBOREUS) FROM THE NORWEGIAN ARCTIC

Environmental Toxicology and Chemistry, 2005

Research paper thumbnail of COMPARATIVE HEPATIC ACTIVITY OF XENOBIOTIC-METABOLIZING ENZYMES AND CONCENTRATIONS OF ORGANOHALOGENS AND THEIR HYDROXYLATED ANALOGUES IN CAPTIVE GREENLAND SLEDGE DOGS (CANIS FAMILIARIS)

Environmental Toxicology and Chemistry, 2009

A captive study was performed with Greenland sledge dogs (Canis familiaris) fed a naturally organ... more A captive study was performed with Greenland sledge dogs (Canis familiaris) fed a naturally organohalogen-contaminated diet (Greenland minke whale [Balaenoptera acutorostrata] blubber; exposed group) or a control diet (pork fat; control group). The catalytic activity of major xenobiotic-metabolizing phase I and II hepatic microsomal enzymes was assessed. Relative to control dogs, ethoxyresorufin-O-deethylase (EROD) activity in exposed dogs was twofold higher ( p ϭ 0.001). Testosterone hydroxylation yielded 6␤-and 16␤-hydroxy (OH) testosterone and androstenedione, with higher rates of production (23-27%; p Յ 0.03) in the exposed individuals. In the exposed dogs, epoxide hydrolase (EH) activity was 31% higher ( p ϭ 0.02) relative to the control dogs, whereas uridine diphosphoglucuronosyl transferase (UDPGT) activity was not different ( p ϭ 0.62). When the exposed and control dogs were combined, the summed (⌺) plasma concentrations of OH-polychlorinated biphenyl (PCB) congeners were predicted by plasma ⌺PCB concentrations and EROD activity ( p Յ 0.04), whereas testosterone hydroxylase, EH, and UDPGT activities were not significant predictors of these concentrations. Consistent results were found for individual OH-PCB congeners and their theoretical precursor PCBs (e.g., 4-OH-CB-187 and CB-183, and 4-OH-CB-146 and CB-146) and for EROD activity. No association was found between ⌺OH-polybrominated diphenyl ether (PBDE) and ⌺PBDE plasma concentrations, or between potential precursor-metabolite pairs, and the enzyme activities. The present results suggest that liver microsomal EROD activity and plasma PCB concentrations have a greater (e.g., relative to EH activity) predictive power for the occurrence of plasma OH-PCB residues in sledge dogs. These results also suggest that plasma OH-PBDEs likely are not products of cytochrome P450mediated transformation but, rather, are accumulated via the diet.

Research paper thumbnail of Trends of Perfluorinated Alkyl Substances in Herring Gull Eggs from Two Coastal Colonies in Northern Norway:  1983−2003

Environmental Science & Technology, 2007

Research paper thumbnail of Brominated Flame Retardants in Glaucous Gulls from the Norwegian Arctic:  More Than Just an Issue of Polybrominated Diphenyl Ethers

Environmental Science & Technology, 2007

Several, unregulated, current-use brominated flame retardants (BFRs), including hexabromobenzene ... more Several, unregulated, current-use brominated flame retardants (BFRs), including hexabromobenzene (HBB), 1,2bis(2,4,6-tribromophenoxy)ethane (BTBPE), pentabromoethylbenzene (PBEB), pentabromotoluene (PBT), and hexabromocyclododecane (as total-(R)-HBCD), were examined in egg yolk and plasma of male and female glaucous gulls (Larus hyperboreus) from the Norwegian Arctic. Also examined were BDE209 and 38 tri-to nona-BDE congeners and brominated biphenyl (BB) 101. The HBB, BTBPE, PBEB, and PBT had high detection frequencies and variability in male and female plasma and egg yolk samples, and their concentrations ranged from nondetectable (<0.02-0.27 ng/g wet wt) to 2.64 ng/g wet wt. The detection frequencies and range of concentrations of non-BDE BFRs were generally highest in plasma of males relative to females. Total-(R)-HBCD concentrations were highest among the non-PBDE BFRs (up to 6.12 and 63.9 ng/g wet wt in plasma and egg yolk, respectively). Next highest was HBB with concentrations within a range comparable to the minor PBDEs monitored (e.g., BDE28, 116 and 155). Sum (Σ) 38 PBDE concentrations ranged from 2.49 to 54.5 ng/g wet wt in plasma and 81.2 to 321 ng/g wet wt in egg yolk. The BDE209 was virtually nondetectable, whereas six octa-BDEs (i.e., BDE196, 197, 201, 202, 203, and 205), as well as three nona-BDEs (i.e., BDE206, 207, and 208, and potential BDE209 debromination products) were found sporadically in plasma and egg yolk. The results from this study suggest that in addition to PBDEs, several currentuse, non-BDE BFRs undergo long-range atmospheric transport and bioaccumulate at low levels in and are maternally transferred (to eggs) in glaucous gulls from the Norwegian Arctic.

Research paper thumbnail of Perfluorinated Alkyl Substances in Plasma, Liver, Brain, and Eggs of Glaucous Gulls ( Larus hyperboreus ) from the Norwegian Arctic

Environmental Science & Technology, 2005

1. Jones, P. D.; Hu, W.; de Coen, W.; Newsted, J. L.; Giesy, J. P. Environ. Toxicol. Chem. 2003, ... more 1. Jones, P. D.; Hu, W.; de Coen, W.; Newsted, J. L.; Giesy, J. P. Environ. Toxicol. Chem. 2003, 22, 2639-2649. 2. Newsted, J. L.; Coady, K. K.; Beach, S. A.; Butenhoff, J. L.; Gallagher, S.; Giesy, J. P. Environ. Toxicol. Pharmacol., submitted. 3. Hansen, K. J.; Clemen, L. A.; Ellefson, M. E.; Johnson, H. O. Environ. Sci. Technol. 2001, 35, 766-770. 4. Berger, U.; Haukås, M. J. Chrom. A., in press.

Research paper thumbnail of Flame Retardants and Methoxylated and Hydroxylated Polybrominated Diphenyl Ethers in Two Norwegian Arctic Top Predators:  Glaucous Gulls and Polar Bears

Environmental Science & Technology, 2005

Research paper thumbnail of Maternal transfer of organohalogen contaminants and metabolites to eggs of Arctic-breeding glaucous gulls

Environmental Pollution, 2006

with the laying order in a three-egg clutch.

Research paper thumbnail of Organohalogen contamination in breeding glaucous gulls from the Norwegian Arctic: Associations with basal metabolism and circulating thyroid hormones

Environmental Pollution, 2007

Basal metabolic rate in glaucous gulls was negatively associated with plasma organochlorine conce... more Basal metabolic rate in glaucous gulls was negatively associated with plasma organochlorine concentrations, but not with circulating thyroid hormone levels.

Research paper thumbnail of Halogenated organic contaminants and mercury in northern fulmars (Fulmarus glacialis): levels, relationships to dietary descriptors and blood to liver comparison

Environmental Pollution, 2007

Halogenated organic contaminants and mercury in northern fulmars (Fulmarus glacialis): levels, re... more Halogenated organic contaminants and mercury in northern fulmars (Fulmarus glacialis): levels, relationships to dietary descriptors and blood to liver comparison Partial dioxin-like toxicity in northern fulmars based on toxic equivalents (TEQs) was well above thresholds for reproductive effects in seabirds.

Research paper thumbnail of Effects of Organochlorine Contaminants on Thyroid Hormone Levels in Arctic Breeding Glaucous Gulls, Larus hyperboreus

Environmental Health Perspectives, 2003

Studies on glaucous gulls (Larus hyperboreus) breeding in the Barents Sea have reported that high... more Studies on glaucous gulls (Larus hyperboreus) breeding in the Barents Sea have reported that high blood levels of halogenated organic contaminants in this species might cause reproductive, behavioral, and developmental stress. However, potential endocrine system modulation caused by contaminant exposure has yet not been reported in this Arctic apical predator. In this present study we aimed to investigate whether the current levels of a selection of organochlorines (OCs) were associated with altered circulating levels of thyroid hormones (THs) in free-ranging adult glaucous gulls breeding at Bear Island in the Barents Sea. Blood concentrations of 14 polychlorinated biphenyls, hexachlorobenzene (HCB), oxychlordane, and p,p´-dichlorodiphenyldichloroethylene (p,p´-DDE) were quantified, in addition to free and total thyroxine (T 4 ) and triiodothyronine (T 3 ), in plasma of 66 glaucous gulls in the spring of 2001. Negative correlations were found between plasma levels of T 4 and T 4 :T 3 ratio, and blood levels of OCs in male glaucous gulls. Despite their relatively low contribution to the total OC fraction, HCB and oxychlordane were the most prominent compounds in terms of their negative effect on the variation of the T 4 :T 3 ratio. Moreover, lower T 4 levels and T 4 :T 3 ratios were measured in glaucous gulls breeding in a colony exposed to high levels of OCs, compared with a less exposed colony. Levels of T 3 were elevated in the high-OC-exposed colony. This may indicate that the glaucous gull is susceptible to changes to TH homeostasis mediated by exposure to halogenated organic contaminants.

Research paper thumbnail of Comparative fate of organohalogen contaminants in two top carnivores in Greenland: Captive sledge dogs and wild polar bears

Comparative Biochemistry and Physiology Part C: Toxicology & Pharmacology, 2008

The limited knowledge and/or the inability to control physiological condition parameters that inf... more The limited knowledge and/or the inability to control physiological condition parameters that influence the fate of organohalogen contaminants (OHCs) has been the foremost confounding aspect in monitoring programs and health risk assessments of wild top predators in the Arctic such as the polar bear (Ursus maritimus). In the present comparative study, we used a potential surrogate Canoidea species for the East Greenland polar bear, the captive sledge dog (Canis familiaris), to investigate some factors that may influence the bioaccumulation and biotransformation of major chlorinated and brominated OHCs in adipose tissue and blood (plasma) of control (fed commercial pork fat) and exposed (fed West Greenland minke whale (Balaenoptera acutorostrata) blubber) adult female sledge dogs. Furthermore, we compared the patterns and concentrations of OHCs and their known or suggested hydroxylated (OH) metabolites (e.g., OH-PCBs) in sledge dogs with those in adipose tissue and blood (plasma) of East Greenland adult female polar bears, and blubber of their main prey species, the ringed seal (Pusa hispida). The two-year feeding regime conducted with sledge dogs led to marked differences in overall adipose tissue (and plasma) OHC residue accumulation between the control and exposed groups. Characteristic prey-to-predator OHC bioaccumulation dynamics for major PCB and PBDE congeners (patterns and concentrations) and biotransformation capacity with respect to PCB metabolite formation and OH-PCB retention distinguished, to some extent, captive sledge dogs and wild polar bears. Based on the present findings, we conclude that the use of surrogate species in toxicological investigations for species in the Canoidea family should be done with great caution, although they remain essential in the context of contaminants research with sensitive arctic top carnivore species such as the polar bear.