Spatio-temporal persistence of scleractinian coral species at Lizard Island, Great Barrier Reef

The Great Barrier Reef is a diverse ecosystem of outstanding universal value that is under an increasing level of cumulative threat. The status of biodiversity, particularly that of habitat-forming taxa is not known, and more data are needed to evaluate this. Here, we summarize scleractinian coral distribution records in the Lizard Island reef system from 1976 to 2020 to explore the persistence of the local species pool across 44 years. By undertaking replicated spatio-temporal biodiversity surveys (2011, 2015, 2017, 2020) at 14 sites and compiling published species records from this location (1976-2020), we determine that 368 species of hermatypic scleractinian coral have been recorded from Lizard Island and/or nearby reefs over the last 44 years. Two hundred and eighty-four of those species (77.2%) have ongoing records across this time period indicating temporal persistence at the local scale. However, 28 species (7.6%) that were reliably recorded prior to 2011 have not been recorded in subsequent years and may be at risk of local extinction. A further 31 species (8.4%) may be at risk of local range reduction as they have not been recorded at Lizard Island and/or at nearby reefs since 2015. The remaining 25 species (6.8%) were deemed taxonomically unreliable records. Fifty-three species are recorded from Lizard Island for the first time in the 2011-2020 surveys, however, further integrated taxonomic research is required to verify some of these records. At a site level, species diversity has been in a state of flux over the 2011-2020 period with significant declines in species richness notable from 2011 to 2017, and significant recovery from 2017 to 2020. Overall, this dataset indicates local extinction or local range reduction is a tangible risk for 59 species (16% of the species pool) in the Lizard Island region. Additional targeted searching for these species along with temporal monitoring of species abundance and size structure is warranted to better understand the status of coral biodiversity at this globally significant location.