Pelagic fish communities (waters with depths >20 m) of Lakes Powell and Mead were examined quarterly from 1995 to1998 using vertical gill nets and a scientific echosounder. Nets captured a total of 449 fish consisting of striped bass (57%/45% [Lake Powell/Lake Mead]), threadfin shad (24%/50%), common carp (15%/4%), walleye (3%), channel catfish (2%), and rainbow trout (<1%). Each reservoir contained concentrations of pelagic species separated by expanses of habitat with few fish (<10 kg ? ha?1). Reservoirs experienced dramatic seasonal and annual fluctuations in pelagic biomass. Lake Powell?s biomass peaked at the Colorado River at 709.7 (�46.5) kg ? ha?1 and Lake Mead?s reached 291.9 (�58.2) kg ? ha?1 at Las Vegas Wash. These locations [...]
