A survey of 2015 Alaska seaplane operations with predictions of transmission risk for aquatic invasive plants.

The main purpose of the survey was to establish the risk domain for introducing Elodea, a genus of aquatic invasive species (AIS), by identifying unique seaplane destinations, flight origin, and annual flight frequency. We designed an electronic mapping tool programmed in JavaScript and using Mapbox Outdoors general-purpose maps (see Figure). The mapping tool enabled precise identification of flying destinations while avoiding spatial ambiguity. We first asked pilots to tell us their home base and then mark their 2015 first-leg freshwater destinations using the mapping tool. Once respondents placed the electronic marker, a pop-up menu asked the pilot to state the 2015 annual flights to the marked destination from their home base using the following intervals: less than 10, 10–25, 25–50, 50–75, 75–100, and more than 100 (Schwoerer et al., 2019). Our targeted population included pilots who flew seaplanes in Alaska in 2015, excluding Southeast Alaska. The sampling considered three pilot groups consisting of pilots who fly seaplanes for personal reasons, commercially, and for the government. We use a hierarchical Bayesian probability model to estimate transmission risk and associated uncertainty for each of 727 seaplane destinations that survey respondents identified.