eNews September 2017

NMSU Student Uses NM WRRI Grant to Monitor Native Fishes in the Gila and Mimbres River Basins (continued)

The viability and distribution of cold-water native fishes are affected strongly by changes in stream temperature and flow rates, including intermittency. These factors are in turn influenced by a changing climate. As Dr. Caldwell has noted in her research, northern New Mexico has experienced an increase in average air temperature of approximately 0.3ºC per decade. In addition, the timing of snowmelt and seasonal flows has also shifted earlier in the year by approximately 11 days, resulting in less discharge during the summer months. Trends like these have brought about some contraction in the historic range of unique native fish populations in the arid Southwest. Thus, there is an ongoing need for the assessment of stream temperature and intermittency monitoring programs in the Gila and Mimbres river basins to effectively manage for the protection and restoration of critical habitat for native cold-water fishes in the future.

Under this grant, Tyler, along with state, federal, and NGO coordinators, established a total of 60 temperature and water intermittency monitors in streams within the Gila and Mimbres drainage system. These sensing devices are also data loggers that record water temperature, air temperature, and relative water conductivity data on an hourly basis. This data can subsequently be accessed and processed to provide useful metrics such as daily average water temperatures, mean weekly maximum temperatures to assist with the assessment of distribution and persistence of a cold-water fish, and monthly averages to gauge easily the likelihood of streams approaching a chronic condition of excessive heat stress for cold-water fishes. The network will help provide state and federal stakeholders and water managers the data needed for model development for assessing the likely effects of regional climate change on the distribution of native fishes, and for water planning in general.

Tyler’s student grant completion report is available on the NM WRRI website and by clicking here.