Repatriation of native fishes to Fossil Creek: An update of efforts from 2007 to 2009

Authors: David E. Jr. Orabutt, Anthony T. Robinson, Codey Carter

Year: 2009 (xli)

Abstract

Fossil Creek is a warm-water perennial tributary stream to the Verde River located in the Gila River Basin of Arizona. For approximately 100 years (early 1900’s to 2004), a majority of the stream water was diverted for hydropower generation. In 2004, a concrete fish barrier was constructed in the lower reaches of Fossil Creek and the nonnative fish removed through chemical renovation. Native fish already present were salvaged and restocked following the treatment. Full flows were restored to Fossil Creek in late 2004. A native fishes repatriation plan was developed by an ad-hoc work group. Six native fish species were proposed for repatriation into Fossil Creek in the near future: loach minnow, Tiaroga cobitis, longfin dace, Agosia chrysogaster, Gila topminnow, Poeciliopsis occidentalis, spikedace, Meda fulgida, razorback sucker, Xyrauchen texanus, and desert pupfish, Cyprinodon macularius. Loach minnow, longfin dace, Gila topminnow, spikedace and razorback sucker were stocked into Fossil Creek from 2007 to 2009 with mixed results. Loach minnow have persisted in apparent low abundance, and longfin dace have persisted though no evidence of reproduction of these species has been detected. Spikedace and razorback sucker were not detected during monitoring one year or two years after the stocking, and likely have not survived or have emigrated from the repatriated reach. Gila topminnow were stocked multiple times and during recent monitoring were detected in the vicinity of four of the seven stocking locations, and had reproduced in at least two locations. We will continue to evaluate, refine, and implement repatriation efforts based on monitoring results.