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

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, ΣTEQs (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.

Toxicity Assessment of Octachlorostyrene in Human Liver Carcinoma (HepG2) Cells

“…According to a report by the United States Environmental Protection Agency (USEPA), OCS has the typical characteristics of a persistent organic pollutant: high lipophilicity, persistency in the environment, and potential for accumulation in organisms. This belief is corroborated by a series of reports showing that OCS has been detected in fish, seafood, birds, mammals, and other organisms [ 1 , 2 , 3 , 4 ]. OCS has been shown to bioaccumulate at levels comparable to those of flame retardants in wildlife of the same species collected at the same location [ 2 ].…”

PCB residues in the tissues of sea ducks wintering on the south coast of the Baltic Sea, Poland

“…The main factor affecting the relatively high TEQ value was the fact that of all dl-PCBs, the dominant congener was PCB 126, which had the highest TEF value. Similarly, PCB 126 was found to be the dominant dl-PCB in the livers in a study of surf scoters from the southern coast of British Columbia (Wilson et al 2010 ). However, the EWI value calculated for the three proposed consumption scenarios was low, and in no case did it exceed the TWI value, set at 14 pg-TEQ/kg/bw.…”

“…Research conducted in various regions of the world indicates that PCBs are still present in the marine environment (Falkowska et al 2016 ; Huber et al 2015 ; Robinson et al 2015 ; Roscales et al 2016 ; Wolschke et al 2015 ; Zheng et al 2018 ) (Table 5 ). Wilson et al ( 2010 ) and Rajaei et al ( 2010 ) reported that the liver of birds from South coast of British Columbia, Canada and Caspian Sea contained 10–30 ng PCBs/g ww. For comparison, the concentration of PCBs in eggs of Common eider from Røst, Norway was 2-fold higher: 76.9 ng/g ww (Huber et al 2015 ).…”

Hepatic ethoxyresorufin-O-deethylase induction in the common kingfisher from an electronic waste recycling site

“…Strong correlations between EROD activity and circulating plasma levels of BDEs 208, 206, and 197 and the hepatic concentration of BDE 208 also were observed in American kestrel ( F. sparverius ) dosed with BDE 209 . However, no EROD–PBDE correlation has been found in young American kestrels ( F. sparverius ) dosed with lower brominated PBDEs in the laboratory or in breeding ring‐billed gulls ( Larus delawarensis ) , Forster's terns ( Sterna forsteri ) , Caspian terns ( Hydroprogne caspia ) , and surf scoters ( Melanitta perspicillata ) that were exposed to several organohalogen compounds, including PBDEs, in the field. The results indicate that the EROD–PBDE correlation in birds appears to be species‐specific, possibly resulting from the differences in the sequence of the AhR .…”