Drone-based water sampling and characterization of three freshwater harmful algal blooms in the United States

Freshwater harmful algal blooms (HABs), caused mostly by toxic cyanobacteria, produce a range of cyanotoxins that threaten the health humans and domestic animals. Climate conditions anthropogenic influences such as agricultural run-off can alter onset intensity HABs. Little is known about distribution spread freshwater Current sampling protocols in some lakes involve teams researchers collect samples hand from boat and/or shoreline. Water be collected surface, discrete-depth collections, depth-integrated intervals. These collections are often restricted to certain months year, generally only performed at limited number collection sites. In with active HABs, surface sufficient for HAB water quality assessments. We used unique DrOne Sampling SystEm (DOWSE) three different HABs Ohio (Grand Lake St Marys, GLSM Erie) Virginia (Lake Anna), United States 2019. The DOWSE consisted 3D-printed device tethered drone (uncrewed aerial system, or UAS), was distances (10–100 m) shore an anchored boat. One hundred eighty (40 GLSM, 20 Erie, 120 Anna) were analyzed 18 flights. Our methods included testing cyanotoxins, phycocyanin, nutrients samples. Mean concentrations microcystins (MCs) 15.00, 1.92, 0.02 ppb Anna, respectively. Anna had low levels anatoxin nearly all (111/120) phycocyanin 687, 38, 62 High total phosphorus observed (mean 0.34 mg/L) Erie 0.12 mg/L). highest variability ranged 0.01 mg/L 0.21 mg/L, mean 0.06 mg/L. Nitrate varied greatly across sites, inverse bloom biomass, ranging below detection 3.64 values followed Drones offer rapid, targeted virtually anywhere on lake without need which disturb surrounding water. are, however, their ability operate during inclement weather rain heavy winds. Collectively, our results highlight numerous opportunities drone-based technologies track, predict, respond future.