8123

• UCREFRP Catalog Number: 8123
• Author: Wydoski, R. S.
• Title: Coordinated Hatchery Facility Plan
• USFW Year: 1994.
• USFW - Doc Type: Need for Captive-Reared Endangered Fish and Propagation Facilities.
• Copyright Material: NO

of razorback sucker, bonYtail, humpback chub, and Colorado squawfish are
illustrated in Figures 5, 6, 7, and 8, respectively.
' B. Space and Water Requirements for Indoor Culture of Fish During the First
Growing Season. Culture of the endangered Colorado River fishes during
the first growing season can be accomplished by rearing the fish indoors
for the entire period (See Sections "1-4" below), a combination of indoor
and outdoor culture (See Section "5" below), cage culture in outdoor ponds
(See Section "6" below), or off-channel growout ponds (See Section "7"
below). However, it should be noted that there are advantages and
disadvantages to intensive and extensive rearing of fish. Either method
may be used in the culture of the endangered Colorado River fishes but
should be thoroughly evaluated to determine the best method for culturing
these species.
1. Indoor Feeding Requirements and Growth of Fish. Many factors enter
into the hatchery requirements (i.e., space and water) in the indoor
culture of fish. Water quality and quantity are key factors for
' selection of a fish propagation site. Water quantity places a limit
on the total production of fish. Production can be increased if the
water quantity allows greater water exchange to remove metabolic
wastes such as unionized ammonia that is highly toxic at warm water
temperatures and at high pH values. Water quality is the most
critical factor in propagation of fish since water temperature,
dissolved gases, pH, suspended solids, acidity, alkalinity, dissolved
minerals, and contaminants affect the well-being of fish. The
experience of the hatchery manager and assistant manager is vital in
operation and management of hatchery facilities. Numerous references
can be obtained from the published literature that explain the
importance of water quantity and quality, culture techniques, loading
densities, feeding rates, etc. to effective operation and management
' of fish hatcheries (E.g., Allen and Kinney 1981; Bell 1986; Colt and
White 1991; Johnson and Jensen 1991; Hamman 1981x, 1981b, 1982, 1985,
1986, 1987, 1989; Haskell 1959; Piper et al. 1982; Parker and Davis
' 1981; Stickney 1993; Toney 1974, 1992; Westers 1985, 1989). Numerous
other references are available on fish health, nutrition, anesthetics
and drugs, stress related to handling and transporting fish, intensive
culture, and extensive culture.
It would not be feasible to attempt to describe these factors in
detail in this plan. However, a brief explanation provides insight
' into how these factors are used to determine loading rates of fish
based on water flow and fish growth. The following recommendations on
density of fish, dissolved gases, flow, food, and growth are provided
for endangered Colorado River fishes reared in indoor troughs through
' the first growing season:
Dissolved gases. Nitrogen and oxygen are the two most abundant gases
' that dissolve in water. Although the atmosphere contains about four
times more nitrogen than oxygen in volume, freshwater normally
contains about twice as much nitrogen as oxygen when in equilibrium
' with the atmosphere because of the difference in solubility between
the two gases.
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