Mortality rates of small juvenile crown-of-thorns starfish Acanthaster planci on the Great Barrier Reef: implications for population size and larval settlement thresholds for outbreaks

MEPS Marine Ecology Progress Series Contact the journal Facebook Twitter RSS Mailing List Subscribe to our mailing list via Mailchimp HomeLatest VolumeAbout the JournalEditorsTheme Sections MEPS 597:179-190 (2018) - DOI: https://doi.org/10.3354/meps12606 Mortality rates of small juvenile crown-of-thorns starfish Acanthaster planci on the Great Barrier Reef: implications for population size and larval settlement thresholds for outbreaks John K. Keesing1,2,*, Andrew R. Halford1,3, Karina C. Hall1,4 1Australian Institute of Marine Science, PMB 3, Townsville MC, Townsville 4810, QLD, Australia 2Present address: CSIRO Oceans and Atmosphere and University of Western Australia Oceans Institute, Indian Ocean Marine Research Centre, M097, 35 Stirling Highway, Crawley, WA 6009, Australia 3Present address: Pacific Community, BP D5, Noumea, 98848, New Caledonia 4Present address: New South Wales Department of Primary Industries and Southern Cross University, National Marine Science Centre, PO Box 4321, Coffs Harbour, NSW 2450, Australia *Corresponding author: john.keesing@csiro.au ABSTRACT: Crown-of-thorns starfish Acanthaster planci are a significant predator of scleractinian corals, with outbreak populations continuing to impose large-scale mortality on coral reef communities. We measured mortality rates of small post-settlement juvenile A. planci in a caging experiment on the Great Barrier Reef. Starfish 3 mm in diameter suffered mortality rates of 2.6% d-1, of which 73.0% was attributed to mobile predators. Starfish 13 mm in diameter had a lower rate of mortality of 0.82% d-1. There were no differences in mortality rates between sites, and localised effects, such as the presence of specific predators like the shrimp Hymenocera sp., affected within-site variability in mortality rates. The coral rubble habitat where the experiments were conducted had a large suite of generalist putative predators including both fish and invertebrates. The results from this and previously published studies were used to develop a model of size- and age-dependent mortality, which, when applied with the commonly accepted destructive outbreak threshold for adult A. planci of 10 ha-1 at age 2.5 yr, would require larval settlement rates of 5 m-2. Parameterising the magnitude of likely settlement rates and rates of post-settlement mortality provides a significant advance in understanding and modelling the population dynamics of this important coral predator. KEY WORDS: Acanthaster · Predation · Mortality · Recruitment · Thresholds · Larval settlement · Coral reefs Full text in pdf format PreviousNextCite this article as: Keesing JK, Halford AR, Hall KC (2018) Mortality rates of small juvenile crown-of-thorns starfish Acanthaster planci on the Great Barrier Reef: implications for population size and larval settlement thresholds for outbreaks. Mar Ecol Prog Ser 597:179-190. https://doi.org/10.3354/meps12606 Export citation RSS - Facebook - Tweet - linkedIn Cited by Published in MEPS Vol. 597. Online publication date: June 11, 2018 Print ISSN: 0171-8630; Online ISSN: 1616-1599 Copyright © 2018 Inter-Research.