Methylmercury biomagnification in an Arctic pelagic food web.
Mercury (Hg) is a toxic element that enters the biosphere from natural and anthropogenic sources, and emitted gaseous Hg enters the Arctic from lower latitudes by long-range transport. In aquatic systems, anoxic conditions favor the bacterial transformation of inorganic Hg to methylmercury (MeHg), which has a greater potential for bioaccumulation than inorganic Hg and is the most toxic form of Hg. The main objective of the present study was to quantify the biomagnification of MeHg in a marine pelagic food web, comprising species of zooplankton, fish, and seabirds, from the Kongsfjorden system (Svalbard, Norway), by use of trophic magnification factors. As expected, tissue concentrations of MeHg increased with increasing trophic level in the food web, though at greater rates than observed in several earlier studies, especially at lower latitudes. There was strong correlation between MeHg and total Hg concentrations through the food web as a whole. The concentration of MeHg in kittiwake decreased from May to October, contributing to seasonal differences in trophic magnification factors. The ecology and physiology of the species comprising the food web in question may have a large influence on the magnitude of the biomagnification. A significant linear relationship was also observed between concentrations of selenium and total Hg in birds but not in zooplankton, suggesting the importance of selenium in Hg detoxification for individuals with high Hg concentrations.
Norwegian Institute for Water Research, Oslo, Norway.
Anders
A
Ruus
Department of Biology, Norwegian University of Science and Technology, Trondheim, Norway.|SINTEF Materials and Chemistry, Marine Environmental Technology, Trondheim, Norway.
Ida B
IB
Øverjordet
Norwegian Institute for Water Research, Oslo, Norway.
Hans Fredrik V
HF
Braaten
Akvaplan-niva, Fram Centre, Tromsø, Norway.|University of Tromsø, The Arctic University of Norway, Tromsø, Norway.
Anita
A
Evenset
Akvaplan-niva, Fram Centre, Tromsø, Norway.
Guttorm
G
Christensen
Norwegian Institute for Air Research, Fram Centre, Tromsø, Norway.
Eldbjørg S
ES
Heimstad
Norwegian Polar Institute, Fram Centre, Tromsø, Norway.
Geir W
GW
Gabrielsen
Norwegian Institute for Water Research, Oslo, Norway.|Department of Biosciences, University of Oslo, Oslo, Norway.
Katrine
K
Borgå
D000818:Animals; D001110:Arctic Regions; D001717:Birds / Q000378:metabolism; D046091:Charadriiformes; D004784:Environmental Monitoring; D005399:Fishes / Q000378:metabolism; D020387:Food Chain; D007553:Isotope Labeling; D013058:Mass Spectrometry; D008767:Methylmercury Compounds / Q000032:analysis*; D009587:Nitrogen Isotopes / Q000737:chemistry; D009664:Norway; D012643:Selenium / Q000032:analysis; D014874:Water Pollutants, Chemical / Q000032:analysis*; D015048:Zooplankton / Q000737:chemistry / Q000378:metabolism
D008767:Methylmercury Compounds; D009587:Nitrogen Isotopes; D014874:Water Pollutants, Chemical; D012643:Selenium
Arctic; Bioaccumulation; Food web; Methylmercury; Trophic magnification