USING CUSTOMIZABLE OPEN SOURCE TECHNOLOGY TO DEVELOP A NETWORK OF STREAM MONITORING STATIONS

This study aims to assess the impacts of water quality during large runoff events on trout populations in the Whitewater River in southeastern Minnesota. To achieve this, open source technology was developed and implemented to collect continuous water quality data and automate water sample collection. The Mayfly motherboard is an Arduino product that allows the user to create code specific to their application. As open source code, it can be accessed by anyone and manipulated to the specifics of their own project. This allows others to have unique water monitoring stations specific to their needs for a fraction of the price.

The hardware consists of three major components; weather station, in-water sonde with water quality sensors, and an automated sampler. Each weather station contains a tipping bucket for precipitation, a thermometer for air temperature, a hygrometer for relative humidity, and a barometric air pressure sensor. The in-stream sensors consist of a Keller Acculevel pressure sensor to detect the water height and a multisensory sonde. The sonde is a Yosemitech Y4000 multi-sonde, which allows for probes to easily be swapped out. Our sondes are outfitted with turbidity, dissolved oxygen, specific conductivity, and pH probes. The automated sampler is a Teledyne ISCO that is controlled directly from the Mayfly, allowing us to trigger a sampling event based on a threshold of any sensor.

We have deployed six of these monitoring stations throughout the Whitewater River, a 830 km² river in the karst landscape of southeastern Minnesota, with a noted trout fishery and with significant agricultural land use in the headwater regions. Sampling events are being triggered based on turbidity in hopes of sampling pollutants that are bonded to sediments transported by the stream during high-flow events. Once we collect water samples from a turbid event, we use the gauge height to create a hydrograph and determine which water samples warrant further chemical testing. Through the chemical analysis, we will estimate the concentrations of the pollutants moving through the river system, possibly having a negative effect on aquatic organisms. Our water quality study is paired with an ecological study assessing the pollutants' impacts on stream health that these washout events might have.