Mercury and persistent organic pollutants in native and invading forage species of the Canadian Arctic: Consequences for food web dynamics. (October 2017)

• Record Type: Journal Article
• Authors: Pedro, Sara; Fisk, Aaron T.; Tomy, Gregg T.; Ferguson, Steven H.; Hussey, Nigel E.; Kessel, Steven T.; McKinney, Melissa A.
• Is Part Of: Environmental pollution. Volume 229(2017)
• Page Start: 229
• Page End: 240
• Publication Date: 2017-10
• Subjects: Arctic -- Climate change -- Organic contaminants -- Invasion -- Mercury; Pollution -- Periodicals; Pollution -- Environmental aspects -- Periodicals; Environmental Pollution -- Periodicals; Pollution -- Périodiques; Pollution -- Aspect de l'environnement -- Périodiques; Pollution -- Effets physiologiques -- Périodiques; Pollution; Pollution -- Environmental aspects; Periodicals; Electronic journals; 363.73
• DOI: 10.1016/j.envpol.2017.05.085
• Languages: English
• ISSNs: 0269-7491

Abstract

Abstract: Contaminant dynamics within Arctic marine food webs may be altered through the climate-driven northward invasions of temperate/boreal species. Here, we compare tissue concentrations of total mercury (THg) and legacy and emerging persistent organic pollutants (POPs) in native versus invading forage species sampled from 2012 to 2014 near Arviat, Clyde River, and Resolute Bay, NU, representing, low, mid- and high eastern Canadian Arctic regions, respectively. Concentrations of THg, legacy Σ-polychlorinated biphenyls (ΣPCB) and Σ-organochlorine (ΣOC) pesticides were detected in all forage species, whereas emerging halogenated flame retardants were detected in only a few individuals. Concentrations of major contaminant groups among regions did not vary for Arctic cod ( Boreogadus saida ), while for sculpin (Cottoidea) there was no clear latitudinal trend. Thus, considering interspecific variation, native sculpin and northern shrimp ( Pandalus borealis ) had the highest overall concentrations of THg (0.17 ± 0.02 and 0.21 ± 0.01 μg g −1 wet weight, respectively), ΣPCB (322 ± 35 and 245 ± 25 ng g −1 lipid weight (lw), respectively), and ΣOC (413 ± 38 and 734 ± 64 ng g −1 lw, respectively). Comparing the keystone native species, Arctic cod, to its 'replacement' species, capelin ( Mallotus villosus ) and sandlance ( Ammodytes spp.), THg concentrations were higher in Arctic cod compared to capelin ( p < 0.001), which was partly explained by differences in fish length. Conversely, capelin and sandlance had higher concentrations of most POPs than Arctic cod ( p < 0.02). Neither feeding habitat (based on δ 13 C), trophic position (based on δ 15 N), nor fish length significantly explained these differences in POPs between Arctic cod, capelin and sandlance. Higher POPs concentrations, as well as variation in congener/compound patterns, in capelin and sandlance relative to Arctic cod seem, therefore, more likely related to a more "temperate"-type contaminant signature in the invaders. Nevertheless, the relatively small (up to two-fold) magnitude of these differences suggested limited effects of these ecological changes on contaminant uptake by Arctic piscivores. Graphical abstract: Highlights: THg and POP levels evaluated in Arctic non-native versus native marine forage fish. Highest levels of THg and POPs found in Arctic natives, sculpin and Northern shrimp. Higher levels of most POPs found in capelin and sandlance relative to Arctic cod. Biological/Ecological factors did not explain differences among non-natives and cod. Small magnitude of differences in THg and POPs between natives and non-natives. Abstract : Invading capelin and sandlance showed lower mercury concentrations, but up to two times higher legacy organic contaminants concentrations compared to native Arctic cod.