Effects of synergized rotenone on nontarget organisms in ponds

Applications of 2 or 5 microliter/liter concentrations of synergized rotenone (2.5%) in the Pro-Noxfish formulation to two shallow 0.05-ha ponds caused a temporary reduction in both total numbers and diversity of benthic invertebrates and a total mortality of cagesd Asiatic clams in both ponds, and a partial mortality of a resident population of larval leopard frogs in the 5 microliter/liter treatment. At day 7 after treatment, benthic organisms(no./meter squared) were reduced 67% by the 2-microliter/ liter concentration and 96% by the 5 microliter/liter application. The diversity index declined sharply in both days between days 3 and 7 after treatment, the lowest values being recorded on day 7 and day 37 in the 2- or 5 microliter/liter treatments respectively. The equitability index declined from day 3 to day 37 in both ponds. By day 69, however, total numbers of benthic organisms had more than doubled over those originally present in the 2 microliter/liter treatment (121% increase), h