Nocturnal fish utilization of a subtropical mangrove-seagrass ecotone

Several studies indicate that, during daylight hours, mangrove-lined shorelines can harbor high fish densities, with individuals presumably benefitting from reduced predation risk among the prop roots (e.g. Parrish 1989; Robertson & Blaber 1992; Laegdsgaard & Johnson 1995). Within mangrove shorelines, fish densities tend to be lower at night, as components of the assemblage disperse into adjacent habitats to forage, returning back to the prop roots before, or soon after, daybreak (Rooker & Dennis 1991; Nagelkerken et al. 2001; Ley & Halliday 2007). Based on evidence from gut contents (Randall 1967), stable isotope (Kieckbusch et al. 2004; Nagelkerken & van der Velde 2004a,b) and tagging investigations (Verweij & Nagelkerken 2007; Luo et al. 2009), seagrass beds are the prime nocturnal feeding destinations, especially for immature stages of snappers, grunts and other species that ultimately occupy coral reefs as adults.