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(a) The location of Bonaire, study site Lac Bay (inset), and the geographical distribution of Halophila stipulacea along 16 Eastern Caribbean islands where H. stipulacea has been recently reported (modified from Willette et al., 2014 and Vera et al., 2014). (b) Aerial picture of the north‐east section of Lac Bay with drawn lines showing the shifting border between grazed (darker) and ungrazed (lighter) Thalassia testudinum (Tt) over multiple years; before H. stipulacea invasion (January 1970, 2010), and after H. stipulacea invasion (February 2012, 2014 and 2016). The border moves towards the shallower area bordering the mangroves (top left). The area between outer lines represents the same “new grazed patches” as in figure panel (c) and is presented as a filled blue polygon. Aerial picture: Google earth 2016. (d) Native T. testudinum with the typical sharp border between ungrazed (top) and grazed (bottom) patches and (e) invasive seagrass H. stipulacea. (c) Foraging hotspots (50% kernel utilization distribution (KUD) home range, line polygons) of five green turtles tracked in 2015 and 2017 concentrate in the area where new cropping (or “grazing”) patches have been initiated in previously ungrazed T. testudinum area (filled blue polygon). Points present the filtered turtle locations for five colour‐marked individuals (with unique PTT ID nr’s): orange 151,225, red 151,221, green 151,222, blue 162,896, purple 162,897. The inset shows the outline of figure panel (b). Photo (d) and (e) by MJAC

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