Dichlobenil as a Herbicide in Fish Habitats

AN IN SITU COMPARISON OF THE EFFECTIVENESS OF FOUR ALGICIDES1

“…In situ bioassays are considered the most direct and relevant approach to measuring biostimulation or toxicity. Duplication of light and temperature regimes are one of the assets of in sir# bioassays (Goldman, 1967), and large enclosure bioassays such as those used in this experiment have been shown to be a valid experimental approach (e.g., Walker, 1959Walker, , 1963Walker, , 1964Walker, , 1965Gerhard and Likens, 1975). While bioassays of various sorts and differing water quality have been conducted for each of the algicides tested in this study, no comprative study has been reported for this combination of algicides.…”

“…Thirty-nine clear polyethylene bags were suspended from floating triangular frames and fdled with 60 liters of pond water. Similar large enclosures have been used in various in situ bioassay studies (e.g., Walker, 1959Walker, ,1963Walker, , 1964Walker, ,1965Gerkart and Likens, 1975;Whittaker, et aL, 1978).…”

The Control of Water Weeds

“…A recent summary of some recommendations for control from U.S.A. literature includes the use of copper sulphate, sodium arsenite, dichlone and endothal [35]. Other chemicals that have been recommended are simazine [105,284], which has been found to give better results under warmer conditions [319]; diuron [276,313] and urea herbicides generally [320]; diquat [134] and paraquat (against Pithophora) [337]; dichlobenil, but not against filamentous algae [323]; chlorthiamid [319] and acrolein [80]. In an experiment where a range of herbicides was tested, mainly against Cladophora, the best results were from copper sulphate and diuron [173].…”

“…General information on the properties of dichlobenil has been given by industry [297] and results on a number of aquatic weeds have been described from U.S.A. by Walker (1964c) and from the Netherlands by van der Weij (1964) and van Buschbach & Elings (1967).…”

“…The question of whether an aquatic herbicide is safe to use when fish are present is obviously important and reference to the toxicities to fish appear in many papers. The question has been intensively studied in U.S.A. by Lawrence (1962Lawrence ( , 1964, Cope (1965), Hughes (1962), Walker (1963Walker ( , 1964cWalker ( , 1965a, and others [52,57,94]. In Germany Bauer (1961) has reviewed the subject extensively as have Bandt, Nehring & Schtitter (1962).…”