title: Optimizing fish sampling for fish-mercury bioaccumulation factors.
abstract: Fish Bioaccumulation Factors (BAFs; ratios of mercury (Hg) in fish (Hgfish) and water (Hgwater)) are used to develop total maximum daily load and water quality criteria for Hg-impaired waters. Both applications require representative Hgfish estimates and, thus, are sensitive to sampling and data-treatment methods. Data collected by fixed protocol from 11 streams in 5 states distributed across the US were used to assess the effects of Hgfish normalization/standardization methods and fish-sample numbers on BAF estimates. Fish length, followed by weight, was most correlated to adult top-predator Hgfish. Site-specific BAFs based on length-normalized and standardized Hgfish estimates demonstrated up to 50% less variability than those based on non-normalized Hgfish. Permutation analysis indicated that length-normalized and standardized Hgfish estimates based on at least 8 trout or 5 bass resulted in mean Hgfish coefficients of variation less than 20%. These results are intended to support regulatory mercury monitoring and load-reduction program improvements.
authors.affiliation: U.S. Geological Survey, Middleton, WI 53562, United States.
authors.forename: Barbara C
authors.initials: BC
authors.lastname: Scudder Eikenberry
authors.affiliation: U.S. Geological Survey, Troy, NY 12180, United States.
authors.forename: Karen
authors.initials: K
authors.lastname: Riva-Murray
authors.affiliation: U.S. Environmental Protection Agency, Athens, GA 30605, United States.
authors.forename: Christopher D
authors.initials: CD
authors.lastname: Knightes
authors.affiliation: U.S. Geological Survey, Columbia, SC 29210, United States.
authors.forename: Celeste A
authors.initials: CA
authors.lastname: Journey
authors.affiliation: U.S. Geological Survey, Tallahassee, FL 32303, United States.
authors.forename: Lia C
authors.initials: LC
authors.lastname: Chasar
authors.affiliation: U.S. Geological Survey, Mounds View, MN 55112, United States.
authors.forename: Mark E
authors.initials: ME
authors.lastname: Brigham
authors.affiliation: U.S. Geological Survey, Columbia, SC 29210, United States. Electronic address: pbradley@usgs.gov.
authors.forename: Paul M
authors.initials: PM
authors.lastname: Bradley
mesh_terms: D000818:Animals; D001492:Bass; D004784:Environmental Monitoring / Q000379:methods*; D005399:Fishes / Q000378:metabolism*; D008628:Mercury / Q000032:analysis / Q000378:metabolism*; D045483:Rivers; D014337:Trout; D014874:Water Pollutants, Chemical / Q000032:analysis / Q000378:metabolism*; D060753:Water Quality
chemical_list: D014874:Water Pollutants, Chemical; D008628:Mercury
keywords: BAF; Bioaccumulation; Fish; Hg criteria; Mercury; TMDL