|SREL Reprint #0538|
of Naturally Occurring Aquatic Organic Fractions on Cadmium Toxicity to Simocephalus
serrulatus (Daphnidae) and Gambusia Affinis (Poeciliidae)
P. Giesy, Jr., G. J. Leversee, and D. R. Williams
Cadmium toxicity to Simocephallus serrulatus
and Gambusia affinis in soft well water, highly organic pond water
and well water containing various sized organic fractions isolated from pond
water was determined and compared to Cd binding capacity of each water type.
Pond organics were separated into three nominal molecular diameter
fractions (>0.0183 pm; 0.0183 <> 0.0032 pm; 0.0032 <> 0.0009 pm)
using ultrafiltration. Cadmium
binding capacity was determined using selective ion electrodes.
Pond water and organic fractions bound Cd, reducing the amount of free
Cd2+ as determined by Cd selective ion electrode.
Whole pond water reduced Cd toxicity to S. serrulatus but
had little effect on Cd toxicity to G. affinis.
The three larger molecular diameter organic fractions reduced Cd toxicity
to S. serrulatus, while the smallest fraction slightly increased
Cd toxicity. Cadmium 96 h LC50 values cannot be predicted from Cd binding
capacities determined by selective ion electrode.
SREL Reprint #0538
Giesy, J.P., Jr., G.J. Leversee, and D.R. Williams. 1977.
Effects of naturally occurring aquatic organic fractions on
cadmium toxicity to Simocephalus serrulatus (Daphnidae) and
Gambusia affinis (Poeciliidae). Water Research 11:1013-1020.