A TEMPORAL AND SPATIAL MULTI-METHOD HYDROGEOCHEMICAL APPROACH TO UNDERSTANDING CRITICAL ZONE PROCESSES AT AGUA REMORA, NM: HABITAT OF THE ENDANGERED ZUNI BLUEHEAD SUCKER

Monitoring temporal and spatial hydrogeochemical characteristics of groundwater and surface water in a 1^st order stream can help to better understand Critical Zone processes. In the semi-arid landscape of New Mexico, groundwater fed springs serve as important aquatic habitat and are also highly susceptible to negative impacts from climate change and land use practices. We report here on springs of the Zuni Mountains region, NM which is the habitat for the endemic Zuni Bluehead Sucker (ZBS) fish. Once common in the Little Colorado River watershed, today over 90% of its range has been reduced and in 2013, the fish and its habitat have been proposed to gain federal protection. To further understand Critical Zone processes that impact the ZBS habitat, we examined Agua Remora (AR), one of three habitat sites. AR is an intermittent creek with a perennial rheocrene spring. The spring flows into three perennial pools within the creek bed. The ZBS are only found in the section of the creek below the spring, although there is a fourth perennial pool above the spring runoff. Beginning in May 2012, both the spring and stream waters were analyzed for geochemical parameters including dissolved oxygen (DO), pH, turbidity, specific conductance, major and trace element concentrations, and stable isotopes of H and O. In addition, instruments were deployed for the continuous monitoring of some of these parameters as well as temperature and depth. Results from this multi-method approach identified two major flow paths at the AR site: relatively quick-flow paths and slower-flow paths. The quick-flow waters are less evolved with a Ca-bicarbonate hydrochemical facies and specific conductance of 160-205 µS/cm, while the slower-flow is more chemically evolved with a Na-bicarbonate hydrochemical facies and 260-370 µS/cm. The quick-flow also shows elevated δD and δ¹⁸O isotopic values than the slower-flow. Understanding the water quality parameters necessary for the ZBS habitat is imperative for the species survival. Using a multi-method approach informs resource managers to mitigate impacts of drought and groundwater depletion which threatens spring fed habitat and populations. Determining the spatial and temporal differences within the 1^st order stream adds to the body of research regarding the Critical Zone and serves as a model for monitoring.