November 2021 Norfolk Island

Project Phoenix has just returned from a collecting trip to Norfolk Island.

Norfolk Island (29.03° S; 167.95° E) is one of the most isolated reefs in the Pacific Ocean according to an index developed by the United Nations Environment Programme (UNEP). The size of the reef surrounding the island is likely to have fluctuated widely since the island was formed by volcanic eruptions between 3.1 and 2.3 million years ago (Jones and McDougall 1973). These features are likely to encourage speciation and endemism. Despite the obvious interest for biogeography, and the Islands proximity to Australia (a two hour flight from Brisbane), there has been remarkable little research on the corals of Norfolk Island. The Museum of Tropical Queensland holds about 20 specimens collected by Neville Coleman in the 1990s and Charlie Veron produced a species list following a short visit in 1997. Veron includes Norfolk Island as a separate ecoregion at the Corals of The World website and lists 31 species occurring there, all but one of which, Pocilliopora aliciae, are also found on the Great Barrier Reef.

Our interest in the corals of Norfolk Island was also stimulated by the magnificent website maintained by Susan Prior which contains numerous images of the corals. Most of the corals imaged by Susan are very similar to those we find on Lord Howe Island, very few of which are found on the Great Barrier Reef.

A potentially endemic lobophyllid in Emily Bay. Photo credit: Andrew Baird

In the course of our four days on Norfolk, we managed to find candidates for all but two of the species on Veron’s list plus we were able to add at least 10 additional species. The coral fauna, like that on Lord Howe and in the Solitary Islands, has been completely misinterpreted in the literature. While it will take us a few years to work out exactly how many species are here and give them good names, it is clear that there is very little overlap with tropical reefs. We suspect that many of the species on Norfolk Island are Tasman Sea endemics.

Collection drying on the deck of at Panorama Apartments. Photo credit: Andrew Baird

While there are problems with the reef in some areas, in particular pollution from ageing septic systems has resulted in recent coral disease and mortality (Ainsworth et al. 2021), most of the underwater scenery is magnificent. Mitch, of Norfolk Island Diving, showed us some of the best dive sites on the island but we really missed a trick by not getting out to Phillip Island, 6 km to the south of the Norfolk, where the reefs sounds majestic. Next time.

Reef-scape around the island. Photo credit: Tom Bridge

We thank Jim Castles, the Norfolk Marine Park Project Officer, Brett of Panorama Apartments, Mitch of Norfolk Island Diving and Susan Prior for their help and advice while on Norfolk.

Literature cited

Jones, J. G., and I. McDougall. 1973. Geological history of Norfolk and Philip Islands, southwest Pacific Ocean. Journal of the Geological Society of Australia 20:239-254.

Ainsworth, T., Heron, S., Lantz, C., and Leggat, W. 2021. Norfolk Island Lagoonal Reef, Ecosystem Health Assessment 2020-2021. Parks Australia.

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