title: Joint estimation of crown of thorns (Acanthaster planci) densities on the Great Barrier Reef.
abstract: Crown-of-thorns starfish (CoTS; Acanthaster spp.) are an outbreaking pest among many Indo-Pacific coral reefs that cause substantial ecological and economic damage. Despite ongoing CoTS research, there remain critical gaps in observing CoTS populations and accurately estimating their numbers, greatly limiting understanding of the causes and sources of CoTS outbreaks. Here we address two of these gaps by (1) estimating the detectability of adult CoTS on typical underwater visual count (UVC) surveys using covariates and (2) inter-calibrating multiple data sources to estimate CoTS densities within the Cairns sector of the Great Barrier Reef (GBR). We find that, on average, CoTS detectability is high at 0.82 [0.77, 0.87] (median highest posterior density (HPD) and [95% uncertainty intervals]), with CoTS disc width having the greatest influence on detection. Integrating this information with coincident surveys from alternative sampling programs, we estimate CoTS densities in the Cairns sector of the GBR averaged 44 [41, 48] adults per hectare in 2014.
authors.affiliation: Australian Institute of Marine Science, Townsville, Queensland, Australia; ARC Centre of Excellence for Coral Reef Studies, James Cook University, Townsville, Queensland, Australia; Department of Mathematics and Statistics, Dalhousie University, Halifax, Nova Scotia, Canada.
authors.forename: M Aaron
authors.initials: MA
authors.lastname: MacNeil
authors.affiliation: Australian Institute of Marine Science, Townsville, Queensland, Australia; The Environment Institute and School of Biological Sciences, University of Adelaide, Adelaide, South Australia, Australia.
authors.forename: Camille
authors.initials: C
authors.lastname: Mellin
authors.affiliation: ARC Centre of Excellence for Coral Reef Studies, James Cook University , Townsville , Queensland , Australia.
authors.forename: Morgan S
authors.initials: MS
authors.lastname: Pratchett
authors.affiliation: Great Barrier Reef Marine Park Authority , Townsville , Queensland , Australia.
authors.forename: Jessica
authors.initials: J
authors.lastname: Hoey
authors.affiliation: Australian Institute of Marine Science , Townsville , Queensland , Australia.
authors.forename: Kenneth R N
authors.initials: KR
authors.lastname: Anthony
authors.affiliation: Australian Institute of Marine Science , Townsville , Queensland , Australia.
authors.forename: Alistair J
authors.initials: AJ
authors.lastname: Cheal
authors.affiliation: Australian Institute of Marine Science , Townsville , Queensland , Australia.
authors.forename: Ian
authors.initials: I
authors.lastname: Miller
authors.affiliation: Australian Institute of Marine Science , Townsville , Queensland , Australia.
authors.forename: Hugh
authors.initials: H
authors.lastname: Sweatman
authors.affiliation: ARC Centre of Excellence for Coral Reef Studies, James Cook University , Townsville , Queensland , Australia.
authors.forename: Zara L
authors.initials: ZL
authors.lastname: Cowan
authors.affiliation: Queensland Parks and Wildlife Service (Marine Parks), Queensland Deptartment of National Parks, Sport and Racing , Brisbane , Queensland , Australia.
authors.forename: Sascha
authors.initials: S
authors.lastname: Taylor
authors.affiliation: Association of Marine Park Tourism Operators , Cairns , Australia.
authors.forename: Steven
authors.initials: S
authors.lastname: Moon
authors.affiliation: Department of Biostatistics, Vanderbilt University Medical Center , Nashville , TN , United States of America.
authors.forename: Chris J
authors.initials: CJ
authors.lastname: Fonnesbeck
keywords: Bayesian analysis; CoTS; Data integration; Mark-recapture; Monitoring