Cutthroat Eggs Project
Bonneville Cutthroat Trout Egg Project
By Markus Schlegel
The Division of Wildlife Resources (DWR) worked in conjunction with the Society to
milk, develop, and hatch Bonneville Cutthroat Trout (BCT) from two separate streams
Fish were shocked by DWR employees with the aid of Society volunteers. The eggs were
fertilized and then incubated in several streamside incubators. The incubators were
made from modified Coleman coolers.
The DWR gave the Society a total of 30,200 Bonneville Cutthroat Trout eggs to oversee.
The first batch of eggs arrived in March 2003. We were only expecting a couple thousand
eggs total. The plan was to stock several lakes and reservoirs in the area with fish
hatched from these eggs. However, it was believed that due to the drought situation in
Utah that these bodies of water may be too low and result in significant winterkill.
Therefore, the Society was given almost all the eggs.
Little Dell Creek had two incubator sites, with a total of three incubators. The lower
site on Little Dell produced the first fry 23 days after being fertilized. Three individual
fry were wiggling around on top of the eggs. The remaining eyed eggs were extremely active.
The Lambs Creek incubators didnít eye up until a week or two later. The water temperature
there averages 45 degrees, so it took a little longer.
We started with 22,800 eggs in the three incubators at Little Dell. Fungus was a big problem
on the lower site at Little Dell due in part to high water temperatures. The upper incubator
site had lower water temperature and resulted in a higher hatch rate. We lost approximately
5,500 eggs in all at both Little Dell sites. This resulted in approximately a 72% hatch rate
for both sites on Little Dell.
Lamb ís Creek on the other hand did great and had very little fungus. Only one or two eggs
were found with fungus each visit. Almost all the eggs eyed up at the lower site. It was a
pleasure to see the upper site spilling over with fry on each visit. Cooler water
temperatures are to thank for this. Averaging right around 48-50 degrees in the afternoon
and very cold in the morning. We calculated a hatch rate approaching 90% with most of the
mortality coming from unfertilized eggs rather than fungus as seen in Little Dell.
Many thanks go out to all the volunteers. This six-week project was made possible because of
the numerous volunteers and the DWR. Thanks and congratulations on a job well done.