Intermittency Evaluation
We modified Onset HOBO Pendant temperature and light data loggers (Model
UA-002-64, Onset Computer Corp, Bourne, MA, USA) per the methods
described by Chapin et al. (2014) to allow loggers to detect presence or
absence of water. The modifications repurpose the light intensity
circuitry to record a non-standardized conductivity measurement, which
serves as a proxy for water presence. These modifications retain the
original capacity of the logger to record temperature. One logger was
placed in the deepest pool to capture potential periods of complete
stream drying, while the other was placed a riffle to capture timing and
duration of periods when the stream was at a no-flow state with limited
connectivity among isolated pools.
We additionally measured stream depth in the same riffle as our data
logger. A t-post marked at 0.1 m intervals was installed in the riffle,
and a trail camera was placed nearby and set to take hourly photos of
the t-post. Data loggers and camera data were collected from April 2022
through March 2023 to capture a complete annual cycle of the drying and
rewetting stages of intermittency. We inspected sensors and cameras
approximately every two months over the survey period, downloading data,
replacing batteries, and repairing equipment as necessary.