This report summarizes monitoring activities conducted by Marsh and Associates, LLC (M&A) during calendar year 2017 for the Gila River Basin Native Fish Monitoring project. The purpose of this project is to monitor the status of wild populations of native fishes to better assess the status of federallisted/candidate fishes within the Gila River Basin. The primary goal of the monitoring program is to detect each native species of interest (focus species) present in each stream and stream reach. Secondarily, to estimate relative abundance (assemblage structure) of the focus species compared to cooccurring species (including non-natives); and lastly to delineate the distributional extent of listed species within occupied streams.
Surveys were conducted on pre-selected streams in major drainages throughout the Gila River Basin (Figure 1) which were identified as requiring ongoing surveys that were not currently being performed by others (agencies, institutions, and private contractors). The focus species in each stream is one or more of four native species currently listed as threatened or endangered; Gila topminnow Poeciliopsis occidentalis, loach minnow Tiaroga cobitis, spikedace Meda fulgida, and Gila chub Gila intermedia, plus roundtail chub Gila robusta.