Gaikowski, M.P., J.J. Rach, and L.A. Lee.  2001a.  Efficacy of hydrogen peroxide to 
control mortality associated with saprolegniasis caused by Saprolegnia parasitica in 
walleye eggs (Stizostedion vitreum).  Study report for a clinical field trial conducted at 
the U.S. Geological Survey, Upper Midwest Environmental Sciences Center.  Submitted 
to the U.S. Food and Drug Administration Center for Veterinary Medicine INAD 10-023.  
August 28, 2001.  332 pp.

Fifteen min hydrogen peroxide treatments (0, 500, 1000, and 3000 ?L/L), concentrations 
that were multiples of the Low Regulatory Priority limit of 500 ?L/L, were administered 
every weekday (Monday-Friday) to rainbow trout Onchorynchus mykiss and steelhead 
trout eggs to determine the margin of safety existing for standard egg treatments.  All 
untreated and treated eggs remained free of fungal infection throughout incubation.  
Hydrogen peroxide treatment reduced the mean percent hatch of rainbow trout eggs by 
1.4 to 5.9% among those treated at 500 ?L/L, 6.8 to 15.4% among those treated at 1000 
?L/L, and 13.2 to 25.3% among those treated at 3000 ?L/L.  Mean percent hatch of 
rainbow trout eggs treated at 1000 ?L/L hydrogen peroxide was 7% lower than that for 
eggs treated at 500 ?L/L hydrogen peroxide.  Mean percent hatch of Skamania strain 
steelhead was significantly reduced by hydrogen peroxide treatment, whereas the mean 
percent hatch of Ganaraska strain steelhead was similar to the mean percent hatch of 
rainbow trout eggs.  Daily percent mortality of rainbow trout eggs increased significantly 
between days 6 and 10 (78 to 135 Daily Temperature Units ?C) of incubation.  
Discontinuing hydrogen peroxide treatments to Skamania strain steelhead eggs from day 
7 to day 11 (78 to 105 DTU ?C) of incubation significantly increased the probability of 
eggs reaching the eyed egg stage.  The mean percent hatch of rainbow trout eggs treated 
with hydrogen peroxide at concentrations up to 1000 ?L/L may be increased if no 
treatments are administered between 70 to 140 DTU ?C.  Mortality of sac-fry was not 
observed at hydrogen peroxide concentrations <1000 ?L/L.  Fish culturists should be 
aware that other species or strains may be more sensitive than rainbow trout.  Other 
species and strains should be initially treated with hydrogen peroxide at 500 ?L/L until 
monitoring of egg mortality identifies the presence or absence of a sensitive period.