Gaikowski, M.P., J.J. Rach, and M. Drobish.  2001b.  Efficacy of hydrogen peroxide to 
control mortality associated with saprolegniasis in walleye eggs (Stizostedion vitreum).  
Study report for a clinical field trial conducted at the U.S. Fish and Wildlife Service, 
Gavins Point National Fish Hatchery.  Submitted to the U.S. Food and Drug 
Administration Center for Veterinary Medicine INAD 10-023.  August 28, 2001.  222 pp.

A clinical field trial was conducted at the Gavins Point National Fish Hatchery (Yankton, 
South Dakota) to evaluate the efficacy of hydrogen peroxide to control mortality 
associated with saprolegniasis in walleye eggs.  Because the trial was initiated with non-
eyed eggs, hatch rate was used to represent mortality.  Twelve test units, each holding 
~254,000 eggs per unit were used during the study.  Five of the test units were treated 10 
times once per day on consecutive days at a nominal concentration of 500 mg H2O2/L 
for 15 minutes using a flow-through system.  A second set of five test units were treated 
10 times once per day on consecutive days at a nominal concentration of 750 mg H2O2/L 
for 15 minutes using a flow-through system. The remaining two test units served as 
untreated controls.  The trial duration, including egg incubation and hatch, was 15 days.  
A sample of eggs from jar 12 (an untreated control) was removed after initiation of the 
treatment and shipped to an independent contract laboratory for identification; fungal 
identification was not completed because bacterial contamination in the sample destroyed 
any viable fungal zoospores during shipment.  The mean hydrogen peroxide 
concentration determined for eggs treated at nominal concentrations of 500 and 750 mg/L 
was 487 (s.d. = 22.9) and 699 (s.d. = 113.9) mg/L, respectively. At the end of the 15-d 
trial, mean percent hatch (based on the number of non-eyed eggs) in the treated units was 
65.5% for those treated at 487 mg/L and 75.5% for those treated at 699 mg/L; control 
percent hatch was 58.3%.  A model with a linear term for treatment as a continuous 
variable adequately fit the data for non-eyed eggs (Scaled deviance=1.00, df=1, P=0.32) 
and indicated an increase in the probability of hatch with increasing hydrogen peroxide 
concentration.