Scavenging amphipods: sentinels for penetration of mercury and persistent organic chemicals into food webs of the deep Arctic Ocean

Environ Sci Technol. 2013 Jun 4;47(11):5553-61. doi: 10.1021/es304398j. Epub 2013 May 22.

Abstract

Archived specimens of the scavenging amphipod Eurythenes gryllus, collected from 2075 to 4250 m below the surface on five expeditions to the western and central Arctic Ocean between 1983 and 1998, were analyzed for total mercury (∑Hg), methyl mercury (MeHg), polychlorinated biphenyls (PCBs) and other industrial or byproduct organochlorines (chlorobenzenes, pentachloroanisole, octachlorostyrene), organochlorine pesticides (OCPs), and polybrominated diphenyl ethers (PBDEs). Median ∑Hg concentrations ranged from 70 to 366 ng g(-1) wet weight (ww). MeHg concentrations (3.55 to 23.5 ng g(-1) ww) accounted for 1.7 to 20.1% (median 3.7%) of ∑Hg. ∑Hg and MeHg were positively and significantly correlated with ww (∑Hg r(2) = 0.18, p = 0.0004, n = 63; MeHg r(2) = 0.42, p = 0.0004, n = 25), but not significantly with δ(13)C nor δ(15)N. Median concentrations of total persistent organic pollutants (POPs) ranged from 9750 to 156,000 ng g(-1) lipid weight, with order of abundance: ∑TOX (chlorobornanes quantified as technical toxaphene) > ∑PCBs > ∑DDTs > ∑chlordanes > ∑mirex compounds > ∑BDEs ∼ ∑chlorobenzenes ∼ octachlorostyrene > α-hexachlorocyclohexane ∼ hexachlorobenzene ∼ pentachloroanisole. Enantioselective accumulation was found for the chiral OCPs o,p'-DDT, cis- and trans-chlordane, nonachlor MC6 and oxychlordane. Lipid-normalized POPs concentrations were elevated in amphipods with lipid percentages ≤10%, suggesting that utilization of lipids resulted in concentration of POPs in the remaining lipid pool. Multidimensional Scaling (MDS) analysis using log-transformed physiological variables and lipid-normalized organochlorine concentrations distinguished amphipods from the central vs western arctic stations. This distinction was also seen for PCB homologues, whereas profiles of other compound classes were more related to specific stations rather than central-west differences.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amphipoda / physiology*
  • Animals
  • Arctic Regions
  • Carbon Isotopes / analysis
  • DDT / analysis
  • Environmental Monitoring / methods
  • Food Chain*
  • Halogenated Diphenyl Ethers / analysis
  • Hydrocarbons, Chlorinated / analysis
  • Lipids / analysis
  • Mercury / analysis*
  • Methylmercury Compounds / analysis
  • Oceans and Seas
  • Organic Chemicals / analysis*
  • Pesticides / analysis
  • Polychlorinated Biphenyls / analysis
  • Toxaphene / analysis
  • Water Pollutants, Chemical / analysis*

Substances

  • Carbon Isotopes
  • Halogenated Diphenyl Ethers
  • Hydrocarbons, Chlorinated
  • Lipids
  • Methylmercury Compounds
  • Organic Chemicals
  • Pesticides
  • Water Pollutants, Chemical
  • nonachlor
  • Toxaphene
  • DDT
  • o,p'-DDT
  • Polychlorinated Biphenyls
  • Mercury