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Adverse effects from environmental mercury loads on breeding common loons.
- Source :
-
Ecotoxicology (London, England) [Ecotoxicology] 2008 Feb; Vol. 17 (2), pp. 69-81. Date of Electronic Publication: 2007 Oct 02. - Publication Year :
- 2008
-
Abstract
- Anthropogenic inputs of mercury (Hg) into the environment have significantly increased in the past century. Concurrently, the availability of methylmercury (MeHg) in aquatic systems has increased to levels posing risks to ecological and human health. We use the common loon (Gavia immer) as an upper trophic level bioindicator of aquatic Hg toxicity in freshwater lakes. Multiple endpoints were selected to measure potential negative impacts from MeHg body burdens on behavior, physiology, survival and reproductive success. A robust spatio-temporal dataset was used that included nearly 5,500 loon Hg measurements over an 18-year period. We measured significant changes related to elevated MeHg body burdens, including aberrant incubation behavior, lethargy, and wing area asymmetry. Mercury body burdens in adult loons increased an average of 8.4% per year. Increasing Hg body burdens reduced the number of fledged chicks per territorial pair, with highest risk loons producing 41% fewer fledged young than our reference group. Our multiple endpoints establish adverse effect thresholds for adult loons at 3.0 ug/g (wet weight) in blood and 40.0 ug/g (fresh weight) in feathers. Mercury contamination in parts of Maine and New Hampshire is a driving stressor for creating breeding population sinks. Standardized monitoring programs are needed to determine if population sinks occur elsewhere and to track aquatic ecosystem responses to changes in Hg emissions and deposition.
- Subjects :
- Animals
Body Burden
Environmental Monitoring
Feathers drug effects
Feathers metabolism
Female
Fresh Water
Lethargy chemically induced
Male
Methylmercury Compounds blood
Nesting Behavior drug effects
New England
Population Density
Time Factors
Water Pollutants, Chemical blood
Wings, Animal drug effects
Wings, Animal growth & development
Birds blood
Methylmercury Compounds toxicity
Reproduction drug effects
Water Pollutants, Chemical toxicity
Subjects
Details
- Language :
- English
- ISSN :
- 0963-9292
- Volume :
- 17
- Issue :
- 2
- Database :
- MEDLINE
- Journal :
- Ecotoxicology (London, England)
- Publication Type :
- Academic Journal
- Accession number :
- 17909967
- Full Text :
- https://doi.org/10.1007/s10646-007-0168-7