Aquatic habitat restoration efforts on private lands in the upper Río Yaqui watershed, Arizona and Sonora

Authors: Valer Austin, Josiah Austin

Year: 2008 (xl)

Abstract

The San Bernardino Valley, a Río Yaqui tributary of southeast Arizona, USA, and northeast Sonora, México, was historically the site of a large ciénega (4 kilometers wide by 16 kilometers long) that harbored a unique assemblage of endemic and range-restricted endangered fishes. Fishes of interest here include the endangered Yaqui chub (Gila purpurea), Sonoran topminnow (Poeciliopsis occidentalis sonoriensis) and and Yaqui catfish (Ictalurus pricei), threatened Sonora sucker (Catostomus bernardini), Mexican stoneroller (Campostoma ornatum), an undescribed southern form of Agosia and others. A number of endangered and threatened aquatic invertebrates and plants also occur on the properties. Unfortunately, the ciénega and their biotic communities were severely damaged by a combination of drought, poor range management practices, and intensive farming. As vegetation was lost from the ciénega during the late 19th Century, intense periodic flooding accelerated erosion and formed head-cuts that slowly drained the majority of the wetland. The Cuenca Los Ojos Foundation (www.cuencalosojos.org), working with land owners and managers on both sides of the international border, is using a variety of restoration methods to recover the ciénega. These methods include: the installation of rock-and-wire gabions to slow flood waters, increase soil deposition, and permit establishment of vegetation in barren washes; extensive rehabilitation of existing wetlands and creation of new ones; and the restoration of uplands to help regulate the water cycle. These efforts have resulted in a dramatic increase in the extent of perennial wetlands, the establishment of vegetation that mediates the effects of floods, and the expansion of native fish populations. We further discuss some lessons learned throughout the process.