Distribution of total and methylmercury in different ecosystem compartments in the Everglades: implications for mercury bioaccumulation.
We analyzed Hg species distribution patterns among ecosystem compartments in the Everglades at the landscape level in order to explore the implications of Hg distribution for Hg bioaccumulation and to investigate major biogeochemical processes that are pertinent to the observed Hg distribution patterns. At an Everglade-wide scale, THg concentrations were significantly increased in the following order: periphyton<flocculent material (floc)<soil, while relatively high MeHg concentrations were observed in floc and periphyton. Differences in the methylation potential, THg concentration, and MeHg retention capacity could explain the relatively high MeHg concentrations in floc and periphyton. The MeHg/THg ratio was higher for water than for soil, floc, or periphyton probably due to high dissolved organic carbon (DOC) concentrations present in the Everglades. Mosquitofish THg positively correlated with periphyton MeHg and DOC-normalized water MeHg. The relative THg and MeHg distribution patterns among ecosystem compartments favor Hg bioaccumulation in the Everglades.
Liu
Guangliang
G
Department of Chemistry and Biochemistry, Florida International University, Miami, FL 33199, USA.
Cai
Yong
Y
Philippi
Thomas
T
Kalla
Peter
P
Scheidt
Daniel
D
Richards
Jennifer
J
Scinto
Leonard
L
Appleby
Charlie
C
D000818:Animals; D002244:Carbon / Q000032:analysis; D003532:Cyprinodontiformes / Q000378:metabolism; D017753:Ecosystem; D004784:Environmental Monitoring / Q000379:methods; D004785:Environmental Pollutants / Q000032:analysis*; D005431:Florida; D020387:Food Chain; D005618:Fresh Water; D005659:Fungicides, Industrial / Q000032:analysis*; D008628:Mercury / Q000032:analysis*; D008629:Mercury Isotopes; D008767:Methylmercury Compounds / Q000032:analysis*; D010933:Plankton; D012987:Soil / Q000032:analysis; D012989:Soil Pollutants / Q000032:analysis; D014874:Water Pollutants, Chemical / Q000032:analysis
D004785:Environmental Pollutants; D005659:Fungicides, Industrial; D008629:Mercury Isotopes; D008767:Methylmercury Compounds; D012987:Soil; D012989:Soil Pollutants; D014874:Water Pollutants, Chemical; D002244:Carbon; D008628:Mercury