An underwater Serengeti: Seagrass‐mediated effects on intake and cultivation grazing behavior of a marine megaherbivore

• DOI: 10.1002/ecs2.4259
• Publication Date: 2022-11-09T09:16:52Z
• Authors: Alexandra G. Gulick; Robert A. Johnson; Laura A. Palma; Ashley M. Kusel; Clayton G. Pollock; Zandy Hillis‐Starr; Alan B. Bolten; Karen A. Bjorndal
• Keywords: Thalassia testudinum; Grazing pressure

Abstract Populations of green turtles ( Chelonia mydas ), a megaherbivore that consumes seagrasses via cultivation grazing, are recovering worldwide. Information on plant‐mediated effects herbivore foraging behavior is critical to understanding plant–herbivore interactions and sustainability grazing as ecosystems continue change. In Caribbean seagrass ecosystem, we use stationary cameras benthic surveys evaluate the morphology leaf nitrogen content turtle behavior. Thalassia testudinum has significant forage intake (in milligrams dry mass [DM] per minute) for turtles, whereas no effect. Intake increases in grazed areas with shorter leaves higher biomass concentration DM cubic centimeter), indicating more efficient under these conditions. Bite rate bites short leaves, result reduced search time. size bite) but dense canopies, because crops shoots each bite. Increased efficiency time high concentrations collectively maximize intake. Ingested than mean height all available areas, selection leaves. Our estimate daily 86.1 g day −1 33‐kg . study provides novel contribution plant‐level cues marine megaherbivore, how optimizes strategy by maximizing