March 2021 Lord Howe Island

Andrew Baird and Tom Bridge have just returned from a week sampling the corals of the Lord Howe Island Marine Park (LHIMP), the world’s southernmost coral reef. Andrew, along with many colleagues from Project Phoenix, has been working to quantify the biodiversity of the corals of the island for over 10 years. On his first trip to the island in 2010, Andrew was assisting Morgan Pratchett who was interested in estimating the growth rates of corals in Lord Howe’s cool subtropical waters. Andrew’s job was to identify the coral species and within minutes of being in the water he realized that despite 20 years of travel throughout the Indo-Pacific he had never seen most of the species. This was quite a surprise because all previous researchers had interpreted the coral fauna of LHIMP as a subset of species from the Great Barrier Reef (Veron & Done 1979; Harriott et al 1995). In particular, not a single endemic species was recognized. This was in stark contrast to the rest of the marine fauna that includes 9 endemic coral reef fish and 47 endemic marine algae.

Photo: A gorgeous shot of Lord Howe Island above and a field of Acropora below surface. Photo credit: Matt Curnock

Now, after 10 years of taxonomic research using multiple lines of evidence, in particular novel molecular tools that promise species level resolution in some of the more challenging taxa such as the Acropora and Montipora, Project Phoenix is ready to put together a preliminary species list for the coral fauna in LHIMP. Highlights include up to 15 Acropora species that are likely to be endemic to south-eastern Australia out of a total of approximately 30 Acropora species that occur on Lord Howe Island; in other words, around 50% of the Acropora species are endemic to LHIMP region. Only 11 of these species occur on the Great Barrier Reef, and most of those only in the southern GBR. Such levels of endemism are much higher than current estimates in any other part of the world (Hughes et al 2002), although our results clearly highlight the need for similar studies in other peripheral subtropical regions such as South Africa and Japan. Similar levels of endemism are likely in most of the other genera that have been examined in detail, including the Montipora, Porites, Favites and Cyphastrea. This work confirms the conservation significance of the LHIMP – clearly one of the most unique and important marine refuges on earth.

Andrew and Tom thank the Lord Howe Island Board, Pro Dive and in particular, Justin Gilligan and Caitlin Woods of the Department of Primary Industry NSW for their time and the use of resources to help collect the corals. They also thank Matt Curnock and Duan Biggs for their assistance in the field and great company, and Matt for his wonderful photos.

Photo: Andrew and Tom upon return from a collection dive. Photo credit: Matt Curnock

Literature cited

Harriot  V. J., P. L. Harrison, and S. A. Banks. 1995. The coral communities of Lord Howe Island. Marine and Freshwater Research 46:457-465.

Hughes, T. P., D. R. Bellwood, and S. R. Connolly. 2002. Biodiversity hotspots, centres of endemicity, and the conservation of coral reefs. Ecology Letters 5:775-784.

Veron, J. E. N., and T. J. Done. 1979. Corals and coral communities of Lord Howe Island. Australian Journal of Marine and Freshwater Research 30:203-236.

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