25
Toxic Thresholds
TABLE 2.2. (Continued)
Selenium
Species
Tissue
concentration
Effect
Reference
Aquatic birds
(Anas sp.)
Whole-body
Whole-body
Ovaries
Eggs
Ovaries
Muscle
Liver
Whole-body
Liver
Eggs
5 f!g/g
19 f!g/g
34 f!g/g
42 f!g/g
18 Ilg/g
16 f!g/g
29 f!g/g
18 Ilg/g
10 f!g/g
7 f!g/g
Mortality
Reproductive
failure
Reproductive
failure
Reproductive
failure
Reproductive
failure
Reproductive
failure
Reproductive
failure
Reproductive
failure
Reproductive
failure
Reproductive
failure
USFWS 1990
Coyle et al. 1993
Coyle et al. 1993
Coyle et al. 1993
Hermanutz et al.
1992
Hermanutz et al.
1992
Hermanutz et al.
1992
Hermanutz et al.
1992
Skorupa, Mormon,
and SefchickEdwards 1996
Skorupa, Mormon,
and SefchickEdwards 1996
Green alga
(Selenastrum
capricornutum)
Whole
organism
20 f!g/g
Reduced cell
replication
Foe and Knight
1986
Cyanobacterium Whole
394 f!g/g
Reduced
Kiffney and
(Anabaena
jIos-aquae)
Cladoceran
(Daphnia
magna)
organism
Whole
organism
Whole
organism
15 f!g/g
32 f!g/g
Chlorophyli-a
Reduced
weight
Reproductive
failure
Knight 1990
Ingersoll, Dwyer,
and May 1990
Ingersoll. Dwyer.
and May 1990
, Selenium concentrations in parts per million on a dry weight basis.
The toxic effect thresholds for selenium impacts on food-chain organisms (20 to 700
Se/g) are much higher than the dietary effect levels for
fish and wildlife. Dietary concentrations of 6.5
Se/g or greater (as
selenomethionine) have been shown to cause mortality and reproductive
failure of centrarchids (Woock et al. 1987; United States Fish and Wildlife
Service [USFWS] 1990; Coyle et al. 1993), while dietary levels of greater
than 3
Se/g reduce survival of juvenile salmonids (Goettl and Davies
1978; Hilton et al. 1980; Hilton and Hodson 1983; Hamilton et al. 1986,
1989, 1990) (Table 2.3). The uptake kinetics and effect levels for natural
field-source selenium diets and seleno-L-methionine spiked commercial