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.

本次调查的核心目标是通过识别独特的水上飞机（seaplane）目的地、飞行起点及年度飞行频次，明确水蕴草属（Elodea）——一种水生入侵物种（aquatic invasive species, AIS）——的传入风险域。我们设计了一款基于JavaScript编程、采用Mapbox Outdoors通用地图的电子绘图工具（见图）。该绘图工具可精准识别飞行目的地，同时规避空间歧义问题。我们首先要求飞行员告知其基地，并使用该绘图工具标记其2015年首段航程的淡水水域目的地。当受访者放置电子标记后，弹出菜单会要求飞行员说明其2015年从基地飞往该标记目的地的年度飞行频次，可选区间为：少于10次、10~25次、25~50次、50~75次、75~100次以及100次以上（Schwoerer等人，2019）。本次调查的目标群体为2015年在阿拉斯加州（不含阿拉斯加东南部）运营水上飞机的飞行员。本次抽样涵盖三类飞行员群体：因私人用途、商业用途及政府公务运营水上飞机的飞行员。我们采用分层贝叶斯概率模型，对受访者识别出的727个水上飞机目的地分别估算其入侵物种传入风险及相关不确定性。