Efficacy of Automated Sampling Buoys Used in the Great Rivers Observatory Network

We address the deployment and efficacy of automated sampling buoys used by the Great Rivers Observatory Network (GREON).  From May to October 2013, the first GREON buoy was deployed in a backwater of Pool 26 of the Mississippi River.  This deployment included a major flood event during the months of May and June.  The GREON buoy was deployed adjacent to an LTRM fixed WQ site, allowing us to assess the accuracy of data from the buoy compared to the traditional sampling methods used by the LTRM program.  Significant linear regressions were found between GREON and LTRM data for all parameters:  temperature (R²=0.93), conductivity (R²=0.82), pH (R²=0.96), DO (R²=0.84), turbidity (R²=0.58), chl-a (R²=0.52), and nitrate (R²=0.99).  The continuous-hourly readings from the GREON buoy allowed us to see trends that would have been missed, especially during flooding when traditional sampling was not possible.  In the fall of 2014, four sampling buoys were deployed in the same area for a little over a month.  Data from the four sampling units was very consistent.  Although automated samplers likely will never entirely replace a traditional water quality sampling, we believe our results show that they can be a valuable compliment to standard water quality sampling.