One argument commonly used against fish pass construction is their high cost (Galli et al., 1984; Torloni, 1984; cited by Valderrama Barco, 1986) compared to that of fish hatcheries (Machado and Alzuguir, 1976).
Godoy (1985), using Brazil as an example, tries to show that this is not necessarily so. The cost of materials for the fishway proposed for Ilha Grande (Table 1) would be three times lower than the construction cost of the Furnas hatchery (Table 2).
The fish elevators, recommended for the Cierre Chapetón in the middle Paraná (Poddubnyi, Espinach Ros and Oldani, 1981) are expected to cost US$ 50 million, whilst the hatchery for the same reservoir (Table 2) will cost US$ 10 million to build and annual operating costs will be US$ 400 000 (Poddunyi et al., 1984).
The approximate cost of equipping the two Borland locks on the Salto Grande (Table 1) was US$ 1.2 million (Boiry and Quirós, 1985). The fish pass and elevator originally proposed for Yaciretá (Table 1) was expected to cost some US$ 36 million (Bienatti, pers. comm.). The Borland locks for Garabí (Table 1) are expected to cost US$ 1.4 million to install and the hatchery US$ 1.8 million (Boiry and Quirós, 1985).
A complete floating unit, like the one recommended for the Middle Paraná project, with facilities for holding and transporting the fish, costs a little over US$ 1 million (Gutiérrez, pers. comm.).
Generally speaking, the investment required to provide fish passes or other mechanisms to pass fish upstream and hatcheries for the large dams scheduled for construction was justified following an analysis of the catch potential of the future reservoir and a prediction of catch composition and landed and retail prices (Poddubnyi et al., 1984; Boiry and Quirós, 1985; Godoy, 1985).
