Ultra low volume aerial application of naled (Dibrom 14) at 0.7 and 1.5 oz per acre were made. The effects of the spray on non target aquatic organisms were monitored utilizing caged fish, shoreline sampling, drift traps, drop traps, acetylcholinesterase levels in fish brain and other observations. Acetylcholinesterase activity in fish brains was depressed in the treated areas but no significant mortality of fish was noted. No gross effects on the normal fauna was observed. From this test it is concluded that no extensive monitoring activities are required for routine spray missions using conventional rates of naled, but closely spaced, multiple applications may require monitoring.