MEPS 574:181-191 (2017)  -  DOI: https://doi.org/10.3354/meps12173

First citizen-science population abundance and growth rate estimates for green sea turtles Chelonia mydas foraging in the northern Great Barrier Reef, Australia

Christine A. M. Hof1, Eddie Smallwood2, Justin Meager3, Ian P. Bell4,*

1WWF-Australia, Level 1, 17 Burnett Lane, Brisbane, Queensland 4000, Australia
2Gudjuda Reference Group Aboriginal Corporation, 134 Young St, Ayr, Queensland 4807, Australia
32 Gympie Street, Landsborough, Queensland 4551, Australia
4Department of Environment and Heritage Protection, Townsville, Queensland 4812, Australia
*Corresponding author:

ABSTRACT: Embayments and coastal reefs of Queensland, Australia have supported some of the highest densities of green sea turtle Chelonia mydas foraging aggregations in the western Pacific Ocean. Since industrialization, many cumulative threats have negatively impacted these turtles with some Aboriginal communities concerned about notable reductions in local abundance and possible end to their customary hunting practice. Guided by collaborators, population trends, survivorship and somatic growth were monitored at a broadly representative inshore site in Edgecumbe Bay, Queensland, using a local citizen-science approach. The 12 yr time series of 1316 tagged turtles from 2003 to 2014 was analysed using Capture Mark Recapture (CMR) and Bayesian growth models. Models indicated the population comprised of 4392 individuals in 2014 and is rebuilding at 8.3% yr–1. The data did not support more complex models with age or time-varied survivorship or recruitment. Overall survival (0.90 apparent survival yr–1) and growth rate (1.20 cm yr-1) were high compared to other green turtle populations globally. This study represents the first population modelling of green turtles foraging in inshore waters of the Great Barrier Reef and north-east Australia and will be an important proxy indicator for how other sites may be functioning. Although methodology and resource capacity should be carefully considered, this study demonstrates that citizen-science CMR studies can generate valid data to support replicable, robust statistical modelling and allow indigenous communities to sustainably manage and protect turtles on indigenous traditional Sea Country within Australia and worldwide.


KEY WORDS: Green sea turtles · Population abundance · Growth rate · Northern Great Barrier Reef · Citizen science · Indigenous and community groups


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Cite this article as: Hof CAM, Smallwood E, Meager J, Bell IP (2017) First citizen-science population abundance and growth rate estimates for green sea turtles Chelonia mydas foraging in the northern Great Barrier Reef, Australia. Mar Ecol Prog Ser 574:181-191. https://doi.org/10.3354/meps12173

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