Remote sensing of invasive floating plant dynamics

Water hyacinth (Pontederia crassipes) is an invasive floating plant that is considered the world’s most damaging aquatic plant. Originally from South America, it was introduced to many countries as an ornamental plant and has now spread to over 50 countries. P. crassipes grows rapidly, doubling in area every 2 weeks, forming dense free-floating mats that block light, deplete oxygen, impede fishing and transportation, and harm native biodiversity. P. crassipes is known to favour tropical climates and eutrophic conditions, however, our understanding of the drivers of floating plant invasions is still limited. Due to their free-floating nature and fast growth rates, the plants’ spatial distribution across large waterbodies can change rapidly. Frequently updated distribution maps are vital to understand plant dynamics but traditional monitoring using boat surveys is time consuming and expensive. This project will utilise and improve on recently developed methods to generate frequent (monthly or better) floating plant maps globally using satellite imagery. Using Google Earth Engine and global datasets this PhD will quantify temporal dynamics of floating plants and determine how climate and other anthropogenic pressures are driving these changes. The research will be conducted in collaboration with stakeholders in Kenya and the USA, with opportunities for fieldwork for ground truthing. The results will provide vital information to inform the management of these invasive species.