Isom 1967; Cope, Wood, and
1970; Adams 1983; Birmingham and Colman
Degradation is far slower in anaerobic sediments than in aerobic
and Salinas 1985).
At the concentrations achieved with the usual dose of 2,4-D, there is
little evidence of toxicity to fish and invertebrates, with some significant
exceptions (Smith and Isom 1967, Vardia and Durve 1981, Couch and Nelson 1982,
Low doses of 2,4-D BEE are toxic to developmental and juvenile
stages of sockeye salmon
chinook salmon, and rainbow
trout, according to McBride, Dye, and Donaldson (1981) and Finlayson and
Verrue (1985). Cope, Wood, and
(1970) found that the propylene
butyl ether ester produced
liver, blood, and central nervous sys-
It apparently does not bioaccumulate to sig-
tem abnormalies in bluegills.
nificant levels in tissues of bluegills, channel catfish, or largemouth bass
Moreover, it can be used only for Eurasian
not be treated with 2,4-D.
milfoil control in Tennessee Valley Authority reservoirs unless specifically
approved by EPA under Section 18 or 24C of FIFRA.
(1981) concluded that there is a wide margin of safety for
humans with respect to the use of 2,4-D.
However, a case study
Hoar et al. 1986) provides evidence for increased risk of non-Hodgkin's
lymphoma among men exposed to 2,4-D for more than 20 days per year.
finding suggests that 2,4-D should not be used in potable water and that
applicators should use every precaution to avoid exposure.
Fluridone is registered under the trade name SONAR and is sold as an
aquatic suspension or as pellets.
A review of its mode of action, effective-
ness, dose, and environmental impacts has been provided by Schmitz (1986).
Fluridone is a slow-acting, rapidly degradable herbicide that is very effec-
tive against a broad spectrum of submersed and emergent aquatic plants
A more complete list of plants controlled by fluridone can be
found in Schmitz (1986) and Westerdahl and Getsinger (1988).
Its action is
inhibit synthesis of plant pigments which protect chlorophyll from
The normal dose for reservoirs with a mean depth greater than
4 m is 2.2 to 4.5 kg (active
and treatments are most effective
when applied prio r to rapid plant growth. T r eatments when plants are visible