Undergraduate Abstract

Lance Salisbury
December 1998

Factors Affecting Razorback Sucker Growth in Lake Mohave Backwaters

A Thesis submitted in partial satisfaction
of the requirement for the degree of

BACHELOR OF ARTS

In

Environmental Studies Program
University of Nevada Las Vegas

by

Lance Salisbury

Fall 1998

Thesis Adviser:
Tom Burke
Regional Fishery Biologist
U.S. Bureau of Reclamation

ABSTRACT

The objective of this study was to analyze and discuss the variables that effect the success of razorback suckers in four Lake Mohave backwater ponds, North Chemeheuvie, Arizona Juvenile, South Sidewinder, and Dandy. Razorback suckers were stocked into Lake Mohave backwater ponds at a desired rate of 1000 fish/acre in February 1997. The ponds were monitored between May and August, and were harvested and stocked into Lake Mohave between September and November 1997. A significant difference in the successful repatriation was noted between the four backwater ponds varying between 46.8% and 25.2%. It was determined that predation, poor water quality, and handling mortality significantly contributed to this high fluctuation in pond productivity. Predators were present at all four backwaters and are theorized to have lowered fish populations in all four backwaters, especially North Chemeheuvie. Low oxygen and high temperatures attributed to lowered fish populations in Arizona Juvenile and South Sidewinder. Along with low oxygen and high temperatures, pH was also a key variable in Arizona Juvenile. South Sidewinder had problems with high temperatures, low oxygen, and high handling losses. Dandy had high water temperatures and a large crayfish population. The influence of predators, poor water quality, and high handling mortality each played a significant role in the varying repatriation levels in all four study ponds.