Project Phoenix has just submitted a final report for funding received from the Lizard Island Reef Research Foundation. Preliminary results of the research into the taxonomy of the reef-building corals of Lizard Island indicate that species richness in many groups of stony coral is 4-5 times higher than previously recognised, largely due to an extraordinary number of undescribed species that are coming to light with the use of modern integrated approaches. For example, of the 64 primary species hypotheses we have developed from the preliminary analysis of our collection of Acropora from Lizard Island, we suggest that 32 are undescribed and a further 16 are species currently in synonym. That means only 16 of these species are included on previous species lists. Therefore, 75 % of the Acropora diversity on Lizard Island is what we call “dark diversity”. 

Another important finding is that many of the species commonly used in experiments at the Lizard Island Research Station do not actually occur on Lizard Island, indeed, many are highly unlikely to be found in Australia. These include the lab rats; A. digitifera, A. millepora, A. nasuta, A. valida and A. tenuis. Furthermore, the species previously identified as A. hyacinthus in an important series of papers on coral population biology based on Trimodal Reef, Lizard Island (Alvarez-Noriega et al. 2016; McWilliam et al. 2023) is a species complex of at least four species (Figure 1). In addition, three of six Acropora species recently listed as at risk of local extinction on Lizard Island (Richards et al. 2021) are highly unlikely to have ever been found on the Great Barrier Reef. It is quite extraordinary that this dark diversity has been hiding in plain sight on one of the best studied reefs in the world and a profound demonstration of the need for a new coral taxonomic framework.

Our preliminary species hypotheses suggest that there are somewhere between 190 and 220 scleractinian species on Lizard Island. This is substantially less than the 368 species listed in Richards et al (2021). While this difference is certainly affected by sampling intensity, as we only spent 10 days on the island in total, we suggest that the true number of species is likely to be around 250 and that the historical list is inflated by differences in taxonomic opinion among observers. The low habitat diversity in the waters surrounding Lizard Island is unlikely to support such a high number of species.

Significant implications arising from this work include the fact that species boundaries, distributions and abundances and the biogeographical affinities of the coral fauna of the Great Barrier Reef all need to be revaluated. Previous species lists are not reliable indicators of historical distributions and the conclusions of research based on the Veron (2000) taxonomic framework (Bellwood and Hughes 2001; Connolly et al. 2005; Dornelas et al. 2006) need to be reevaluated. Given the inadequacies of the current hard coral taxonomic framework, the IUCN Red List is not suitable as a management guide. In the meantime, management strategies that are independent of species level taxonomy need to be developed.

Project Phoenix acknowledges the Lizard Island Reef Research Foundation for funding this project, along with the Queensland Museum Network, James Cook University and the Australian Research Council. We also thank the directors of Lizard Island, Anne Hoggett and Lyle Vail for their continuing support. 

References

Alvarez-Noriega M, Baird AH, Dornelas M, et al. (2016) Fecundity and the demographic strategies of coral morphologies. Ecology 97:3485-3493

Bellwood DR, Hughes TP (2001) Regional-scale assembly rules and biodiversity of coral reefs. Science 292:1532-1534

Connolly SR, Hughes TP, Bellwood DR, et al. (2005) Community structure of corals and reef fishes at multiple scales. Science 309:1363-1365

Dornelas M, Connolly SR, Hughes TP (2006) Coral reef diversity refutes the neutral theory of biodiversity. Nature 440:80-82

McWilliam M, Dornelas M, Alvarez-Noriega M, et al. (2023) Net effects of life-history traits explain persistent differences in abundance among similar species. Ecology 104

Richards ZT, Juszkiewicz DJ, Hoggett A (2021) Spatio-temporal persistence of scleractinian coral species at Lizard Island, Great Barrier Reef. Coral Reefs 

Veron JEN (2000) Corals of the world. AIMS, Townsville