title: The effects of water quality and age on the acute toxicity of copper to the Florida apple snail, Pomacea paludosa.
abstract: Copper (Cu)-containing compounds have been used in Florida as fungicides, herbicides, and soil amendments, resulting in elevated Cu in the aquatic ecosystem. The Florida apple snail (Pomacea paludosa), a key species in south Florida, may be adversely affected by Cu. Water-quality parameters, such as hardness, dissolved organic carbon (DOC), pH, and alkalinity, affect metal bioavailability and toxicity in aquatic organisms; however, it is uncertain to what extent these factors affect Cu toxicity in the Florida apple snail. The research presented here characterized the acute (96-hour) toxicity of Cu in water to the Florida apple snail at various life stages and under different water-quality parameters. Cu was more toxic to juvenile than adult apple snails. There was no difference between the 96-hour LC(50) at pH 5.5 and 6.5; however, the 96-hour LC(50 )values at pH 7.5 and 8.5 were greater than at lower pHs. The decrease in Cu(2+) above pH 7, as predicted by the MINTEQ model, accounted for the pH effect. Cu toxicity decreased as DOC increased from 0.2 to 30 mg/L. Unlike other aquatic organisms, hardness had no effect on Cu toxicity to the Florida apple snail, suggesting another mechanism of toxicity. Whole-body tissue analysis indicated that the lethal body burden of 120-day-old snails exposed to Cu for 4 days was 30 mg/kg Cu dry weight. Multiple regression analysis indicated that Cu toxicity was a function of organism age, DOC, and pH.
authors.affiliation: Ecotoxicology and Risk Assessment Laboratory, Southeast Environmental Research Center, Department of Environmental Studies, Florida International University, 3000 NE 151st Street, North Miami, FL 33181, USA.
authors.forename: E C
authors.initials: EC
authors.lastname: Rogevich
authors.forename: T C
authors.initials: TC
authors.lastname: Hoang
authors.forename: G M
authors.initials: GM
authors.lastname: Rand
mesh_terms: D000367:Age Factors; D000818:Animals; D001682:Biological Availability; D001822:Body Burden; D003300:Copper / Q000378:metabolism / Q000633:toxicity*; D017753:Ecosystem; D006812:Humic Substances / Q000032:analysis; D006863:Hydrogen-Ion Concentration; D007928:Lethal Dose 50; D008018:Life Cycle Stages / Q000187:drug effects; D012908:Snails / Q000187:drug effects* / Q000378:metabolism; D023382:Toxicity Tests, Acute; D014867:Water / Q000737:chemistry*; D014874:Water Pollutants, Chemical / Q000378:metabolism / Q000633:toxicity*
chemical_list: D006812:Humic Substances; D014874:Water Pollutants, Chemical; D014867:Water; D003300:Copper