Mobile marine predators: an understudied source of nutrients to coral reefs in an unfished atoll.

TitleMobile marine predators: an understudied source of nutrients to coral reefs in an unfished atoll.
Publication TypeJournal Article
Year of Publication2018
AuthorsWilliams JJ, Papastamatiou YP, Caselle JE, Bradley D, Jacoby DMP
JournalProc Biol Sci
Date Published2018 03 28
KeywordsAcoustics, Animal Migration, Animals, Coral Reefs, Ecosystem, Female, Male, Nitrogen Cycle, Nutrients, Population Density, Predatory Behavior, Seawater, Sex Factors, Sharks, telemetry, Time Factors

Animal movements can facilitate important ecological processes, and wide-ranging marine predators, such as sharks, potentially contribute significantly towards nutrient transfer between habitats. We applied network theory to 4 years of acoustic telemetry data for grey reef sharks () at Palmyra, an unfished atoll, to assess their potential role in nutrient dynamics throughout this remote ecosystem. We evaluated the dynamics of habitat connectivity and used network metrics to quantify shark-mediated nutrient distribution. Predator movements were consistent within year, but differed between years and by sex. Females used higher numbers of routes throughout the system, distributing nutrients over a larger proportion of the atoll. Extrapolations of tagged sharks to the population level suggest that prey consumption and subsequent egestion leads to the heterogeneous deposition of 94.5 kg d of nitrogen around the atoll, with approximately 86% of this probably derived from pelagic resources. These results suggest that sharks may contribute substantially to nutrient transfer from offshore waters to near-shore reefs, subsidies that are important for coral reef health.

Alternate JournalProc. Biol. Sci.
PubMed ID29563260
PubMed Central IDPMC5897630
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