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Properties of blood, porphyrins, and exposure to legacy and emerging persistent organic pollutants in surf scoters (Melanitta perspicillata) overwintering on the south coast of British Columbia, Canada.

Wilson LK, Harris ML, Trudeau S, Ikonomou MG, Elliott JE - Arch. Environ. Contam. Toxicol. (2010)

Bottom Line: In addition, a low proportion of lymphocytes in individuals across locations in early spring samples was associated with poor body condition.The apparent loss of fitness just prior to the onset of northerly migrations to breeding grounds is of particular concern.Compromised health of mature birds at this point in the season might impact negatively on the productivity and survival of some individuals, particularly those overwintering in Howe Sound.

View Article: PubMed Central - PubMed

Affiliation: Canadian Wildlife Service, Pacific Wildlife Research Centre, Environment Canada, 5421 Robertson Rd., RR1, Delta, BC, V4K 3N2, Canada.

ABSTRACT
The surf scoter (Melanitta perspicillata) is a little-studied species of North American sea duck. Estimates suggest it has experienced a precipitous decline in breeding numbers over the latter half of the past century. To investigate the potential role of contaminant uptake and toxicity in the population decline, this study undertook to measure blood chemistry, porphyrin concentrations, EROD, and organic contaminants in mature surf scoters wintering in the Strait of Georgia, BC, Canada. Hepatic organochlorine pesticide, polychlorinated dibenzo-p-dioxin, polychlorinated dibenzofuran, polychlorinated biphenyl (PCB), polybrominated diphenyl ether, and nonylphenol concentrations were relatively low; for example, SigmaTEQs (toxic equivalents) for PCBs, dioxins, and furans combined ranged from 4.7 ng/kg wet weight in reference-site (Baynes Sound) birds to 11.4 ng/kg wet weight in birds from Vancouver Harbour. Nonetheless, elevated EROD activity indicated that birds in Howe Sound were responding to an Ah-receptor-mediated stressor, which was also affecting hematocrit values and possibly vitamin A status. In addition, a low proportion of lymphocytes in individuals across locations in early spring samples was associated with poor body condition. The apparent loss of fitness just prior to the onset of northerly migrations to breeding grounds is of particular concern. Compromised health of mature birds at this point in the season might impact negatively on the productivity and survival of some individuals, particularly those overwintering in Howe Sound.

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Related in: MedlinePlus

The geographic differences in hepatic EROD activity and hematocrit values of adult male surf scoters collected from three locations in the Strait of Georgia, BC, 1998–2001. The significant association between EROD and hematocrit values is expressed in the bottom graph (see results text for r and p-values). Bars with different letters above them represent significantly different least squares mean values. Error bars represent upper and lower confidence intervals. ** p < 0.01; *** p < 0.001
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Fig2: The geographic differences in hepatic EROD activity and hematocrit values of adult male surf scoters collected from three locations in the Strait of Georgia, BC, 1998–2001. The significant association between EROD and hematocrit values is expressed in the bottom graph (see results text for r and p-values). Bars with different letters above them represent significantly different least squares mean values. Error bars represent upper and lower confidence intervals. ** p < 0.01; *** p < 0.001

Mentions: Hepatic EROD activity and blood hematocrit values showed no significant seasonal or yearly variability within each location sample population; however, there were significant differences in both variables among locations (Fig. 2, Table 3). EROD was significantly elevated (p = 0.001, n = 40) and hematocrit significantly depressed (p = 0.002, n = 40) in adult male birds collected from Howe Sound, compared to the reference birds at Baynes Sound or the neighboring population in Vancouver Harbour. Moreover, there was a significant negative correlation between EROD and hematocrit (Pearson r = –0.479, p = 0.005), most apparent in the Howe Sound individuals (Fig. 2). Although low sample sizes precluded similar assessments with female birds, it is worth noting that juvenile females from Howe Sound exhibited the most elevated EROD activity; three individuals showed values above 250 pmol/mg protein/min (Table 3).Fig. 2


Properties of blood, porphyrins, and exposure to legacy and emerging persistent organic pollutants in surf scoters (Melanitta perspicillata) overwintering on the south coast of British Columbia, Canada.

Wilson LK, Harris ML, Trudeau S, Ikonomou MG, Elliott JE - Arch. Environ. Contam. Toxicol. (2010)

The geographic differences in hepatic EROD activity and hematocrit values of adult male surf scoters collected from three locations in the Strait of Georgia, BC, 1998–2001. The significant association between EROD and hematocrit values is expressed in the bottom graph (see results text for r and p-values). Bars with different letters above them represent significantly different least squares mean values. Error bars represent upper and lower confidence intervals. ** p < 0.01; *** p < 0.001
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC2908456&req=5

Fig2: The geographic differences in hepatic EROD activity and hematocrit values of adult male surf scoters collected from three locations in the Strait of Georgia, BC, 1998–2001. The significant association between EROD and hematocrit values is expressed in the bottom graph (see results text for r and p-values). Bars with different letters above them represent significantly different least squares mean values. Error bars represent upper and lower confidence intervals. ** p < 0.01; *** p < 0.001
Mentions: Hepatic EROD activity and blood hematocrit values showed no significant seasonal or yearly variability within each location sample population; however, there were significant differences in both variables among locations (Fig. 2, Table 3). EROD was significantly elevated (p = 0.001, n = 40) and hematocrit significantly depressed (p = 0.002, n = 40) in adult male birds collected from Howe Sound, compared to the reference birds at Baynes Sound or the neighboring population in Vancouver Harbour. Moreover, there was a significant negative correlation between EROD and hematocrit (Pearson r = –0.479, p = 0.005), most apparent in the Howe Sound individuals (Fig. 2). Although low sample sizes precluded similar assessments with female birds, it is worth noting that juvenile females from Howe Sound exhibited the most elevated EROD activity; three individuals showed values above 250 pmol/mg protein/min (Table 3).Fig. 2

Bottom Line: In addition, a low proportion of lymphocytes in individuals across locations in early spring samples was associated with poor body condition.The apparent loss of fitness just prior to the onset of northerly migrations to breeding grounds is of particular concern.Compromised health of mature birds at this point in the season might impact negatively on the productivity and survival of some individuals, particularly those overwintering in Howe Sound.

View Article: PubMed Central - PubMed

Affiliation: Canadian Wildlife Service, Pacific Wildlife Research Centre, Environment Canada, 5421 Robertson Rd., RR1, Delta, BC, V4K 3N2, Canada.

ABSTRACT
The surf scoter (Melanitta perspicillata) is a little-studied species of North American sea duck. Estimates suggest it has experienced a precipitous decline in breeding numbers over the latter half of the past century. To investigate the potential role of contaminant uptake and toxicity in the population decline, this study undertook to measure blood chemistry, porphyrin concentrations, EROD, and organic contaminants in mature surf scoters wintering in the Strait of Georgia, BC, Canada. Hepatic organochlorine pesticide, polychlorinated dibenzo-p-dioxin, polychlorinated dibenzofuran, polychlorinated biphenyl (PCB), polybrominated diphenyl ether, and nonylphenol concentrations were relatively low; for example, SigmaTEQs (toxic equivalents) for PCBs, dioxins, and furans combined ranged from 4.7 ng/kg wet weight in reference-site (Baynes Sound) birds to 11.4 ng/kg wet weight in birds from Vancouver Harbour. Nonetheless, elevated EROD activity indicated that birds in Howe Sound were responding to an Ah-receptor-mediated stressor, which was also affecting hematocrit values and possibly vitamin A status. In addition, a low proportion of lymphocytes in individuals across locations in early spring samples was associated with poor body condition. The apparent loss of fitness just prior to the onset of northerly migrations to breeding grounds is of particular concern. Compromised health of mature birds at this point in the season might impact negatively on the productivity and survival of some individuals, particularly those overwintering in Howe Sound.

Show MeSH
Related in: MedlinePlus