Another major constraint to using
surface water for hatcheries is the
potential for contamination by fish
disease organisms or water-borne
predators. Most surface waters
have a resident fish community.
The fish in the water supply may
serve as a reservoir for fish disease
organisms that could enter the
hatchery and cause major losses.
Natural predators of catfish fry,
such as wild fish, insects, and
other invertebrates, can also enter
a hatchery and cause losses of fry.