Summary

Description

Stream temperature was monitored at 18 sites on 14 rivers in Togiak National Wildlife Refuge between 2001 and 2012. Temperature was recorded on an hourly basis using Onset TidbiT dataloggers and the data were successfully recovered from the field 76 of the time. Over 1.4 million hourly temperature records have been collected, qualitygraded, and entered into a relational database. Maximum daily mean temperature readings varied from 11.519.6 C between sites, with the Kukaktlim Lake outlet site being the warmest and the Weary River the coldest. Peak temperature readings were recorded over a 24hour period during July of 2004 at 15 of 18 sites. Trends in temperature decreased among years at one or more sites nine months out of the year, with a statistically significant cooling trend detected at 13 of 18 sites during the month of June. Annual differences in the Pacific Decadal Oscillation PDO index were significantly correlated with monthly mean temperature changes at Kagati Lake outlet, Kukaktlim Lake outlet, Nichols Lake outlet, Osviak River, and Pungokepuk Creek during the month of June.