Geographic trend in mercury measured in common loon feathers and blood
- Univ. of Minnesota, St. Paul, MN (United States). Dept. of Fisheries and Wildlife
- BioDiversity, Inc., Freeport, ME (United States)
- Wisconsin Dept. of Natural Resources, Monona, WI (United States). Bureau of Research
- Michigan State Univ., Lansing, MI (United States). Animal Health Diagnostic Lab.
- Fish and Wildlife Service, Concord, NH (United States)
- Environment Canada, Sackville, New Brunswick (Canada). Canadian Wildlife Service
- Canadian Wildlife Service, Hull, Quebec (Canada). National Wildlife Research Centre
The common loon (Gavia immer) is a high-trophic-level, long-lived, obligate piscivore at risk from elevated levels of Hg through biomagnification and bioaccumulation. From 1991 to 1996 feather and blood samples from adult loons were collected between June and September in five regions of North America: Alaska, northwestern US, Upper Great Lakes, New England, and the Canadian Maritimes. Concentrations of Hg in adults ranged from 2.8 to 36.7 {micro}g/g in feathers and from 0.12 to 7.80 {micro}g/g in whole blood. Blood Hg concentrations in 3 to 6-week-old juveniles ranged from 0.03 to 0.78 {micro}g/g. To better interpret exposure data, relationships between blood and feather Hg concentrations were examined among age and sex classes. Blood and feather Hg correlated strongest in areas with the highest blood Hg levels, indicating a possible carryover of breeding season Hg that is depurated during winter remigial molt. Mean blood and feather Hg concentrations in males were significantly higher than concentrations in females for each region. The mean blood Hg concentration in adults was 10 times higher than that in juveniles, and feather Hg concentrations significantly increased over 1 to 4-year periods in recaptured individuals. Geographic stratification indicates a significant increasing regional trend in adult and juvenile blood Hg concentrations from west to east. This gradient resembles US Environmental Protection Agency-modeled predictions of total anthropogenic Hg deposition across the US. This gradient is clearest across regions. Within-region blood Hg concentrations in adults and juveniles across nine sites of one region, the Upper Great Lakes, were less influenced by variations in geographic Hg deposition than by hydrology and lake chemistry. Loons breeding on low-pH lakes in the Upper Great Lakes and in all lake types of northeastern North America are most at risk from Hg.
- OSTI ID:
- 580748
- Report Number(s):
- CONF-9604239-; ISSN 0730-7268; TRN: IM9807%%2
- Journal Information:
- Environmental Toxicology and Chemistry, Vol. 17, Issue 2; Conference: Wildlife Mercury Conference, Fairfax, VA (United States), 12-13 Apr 1996; Other Information: PBD: Feb 1998
- Country of Publication:
- United States
- Language:
- English
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