Marine predator super-habitats: Channels used for foraging, resting, mating, and parturition in sharks

Conservation measures for marine animals include protecting habitats that are important for foraging, reproduction, and refuging. This can be particularly challenging for mobile marine animals such as sharks that may use a wide range of habitats across life stages and for important ecological events. Channels connecting coastal ocean habitats with lagoons or estuaries are well known for their high abundance of predators and other fishes. Using a combination of biologging and diving observations, we show that a single channel in Fakarava, French Polynesia, is used for foraging, refuging, mating, and parturition by the grey reef shark, Carcharhinus amblyrhinchos. Despite over 500 sharks using and being residential to this channel, grey reef sharks can complete most of their life stages in a single restricted habitat. We classify this channel as a ‘super-habitat’ and propose that channels may be even more important to marine predators than previously thought and should be incorporated into conservation planning.