In Arizona, various nonnative trout have been stocked since the early 1900s, and trout angling remains an important component of the sportfishing industry. These nonnative rainbow trout may have contributed to the decline of Little Colorado spinedace. The overall purpose of the research was to define interactions so that impacts to both trout management and spinedace populations can be minimized. Our objectives covered 5 broad areas of potential interaction: habitat use, diet, predation, health, and distribution.

Although not Federally listed as threatened or endangered, the roundtail chub, also a sportfish in Arizona, is nearly extirpated from sections of the Verde and Salt river drainages. The purpose of this investigation, from March 1998 through March 2000, was to describe ecological requirements and population dynamics of roundtail chub. The objectives were to describe species composition, distribution and abundance, quantify habitat selection by different life stages, estimate population size, quantify movement and age and growth, and describe the reproductive capacity of roundtail chub.