Daily, seasonal, and annual variability of temperature in streams inhabited by the endemic San Pedro Martir trout (Oncorhynchus mykiss nelsoni), in Baja California, Mexico, and the predicted temperature for the years 2025 and 2050

The present study measured the daily, seasonal, and annual variability of the water temperature of streams in which the endemic rainbow trout, Oncorhynchus mykiss nelsoni, is distributed on the western slope of the Sierra San Pedro Martir, Baja California, Mexico, between 1996 and 2019. The seasonal thermal interval and daily duration of summer temperatures above the thermal threshold for this trout subspecies (>= 28 degrees C) were determined in streams at different elevations (553, 1,220, and 2,080 m asl, or meters above sea level). Temperatures 28 degrees C were recorded at the study site on the stream with the lowest elevation (San Antonio de Murillos Creek) over an accumulated 365 h between June and September 2014, with the maximum temperature recorded there, 30.66 degrees C, making it the site most vulnerable to global warming. At the San Antonio de Murillos Creek site, the average water temperature predicted by three models (GFDL R30, HadCM3, and Mote) for the year 2025 would be a non-lethal temperature,