Priscilla H. C. Crawford

Surveying Oklahoma’s Public Lakes for Aquatic Invasive Plants

Over the course of the four survey years (2016-2018, and 2020), I surveyed 516 public access points at 147 Oklahoma lakes.  Due to the record setting statewide precipitation in the spring of 2019, lake levels across Oklahoma were several feet above normal pool levels.  With lake elevations significantly higher, surveys for aquatic invasive plants on/near shore would not detect the presence of deeply submerged vegetation.  Many public access points were underwater, inaccessible, and closed for safety during 2019.  The fourth year of data collection was postponed until 2020.  

All lakes listed in the Lakes of Oklahoma (Oklahoma Water Resources Board, 2021, https://www.owrb.ok.gov/news/publications/lok/lok.php).  Access points included fishing piers, boat ramps and docks, marinas, and swim beaches.  We made visual surveys and sampled by boat and rake when we observed any emergent or submerged aquatic vegetation within 50 m of each side of the sample area.  Positive occurrences were reported iNaturalist. We found aquatic invasive species at 45 access points at 25 lakes.  The most commonly found invasive species was Eurasian Milfoil (Myriophyllum spicatum) at 14 lakes across the state.  Additionally significant infestations were found of Alligator Weed (Alternanthera philoxeroides) along Kerr Lake and Webbers Falls Lake, both on the McClellan-Kerr Navigation channel.

Check out the Oklahoma Invasive Plant Council’s webinar on Aquatic Invasive Plants to learn more about this project! This project starts at approximately 23:30.