The coral communities of Lord Howe Island

Abstract

Lord Howe Island (31�33′S, 159�05′E) is surrounded by the southern-most coral reefs in the Pacific Ocean. The status of the benthic communities at Lord Howe Island was quantified in 1992-93 using replicated video-transects at 20 sites in the shallow reefal area (<20 m depth). The cover of hard coral was comparable with coral cover on some tropical reefs, ranging from less than 10% at some reef flat sites to greater than 40% cover at two seaward beach sites. The process of reef formation is apparently slow, and accretion of limestone is localized. A total of 59 scleractinian coral species were recorded during this study (including 19 new records), bringing the total number recorded at Lord Howe Island to 83. The coral communities contain a unique association of tropical species at their southern limits of distribution, and subtropical species which are rare or absent from the Great Barrier Reef. Many of the species that have been recorded from Lord Howe Island are rare, and may have resulted from chance recruitment of only a few larvae. There have been few major changes in the coral communities at Lord Howe Island in the past 16 years. At two inshore sites there was an apparent reduction in hard coral cover in the 1980s.

Genetic diversity and connectivity in a brooding reef coral at the limit of its distribution

“…(c) Larval dispersal to subtropical reefs Dispersal from tropical to subtropical reefs along EA over an evolutionary timeframe is supported by the occurrence of approximately 155 coral species in 42 genera shared between the GBR and the high-latitute offshore EA reefs (Veron & Done 1979;Hutchings et al 1992;Veron 1993;Harriott et al 1995;Oxley et al 2004, P. Harrison & A. Noreen 2007. Although approximately a dozen coral genera have been found rafting (e.g.…”

“…A large proportion of coral species sampled at these locations were sexually reproductive (Hutchings et al 1992;Harrison 2008). These reefs lie in the path of the warm, south and east flowing EAC, which not only acts as a conduit for larval transport from further north, but provides the climate needed for these warm-water reefs to exist (Veron & Done 1979;Hutchings et al 1992;Harriott et al 1995;Harrison & Booth 2007).…”

“…These reefs have a unique mix of temperate, subtropical and tropical biota and represent the highest latitude species records for many tropical taxa (Hutchings et al 1992;Veron 1993;Harriott et al 1995;Oxley et al 2004;P. Harrison & A. Noreen 2007, unpublished data).…”

Development of a Seamless, High-Resolution Bathymetric Model to Compare Reef Morphology around the Subtropical Island Shelves of Lord Howe Island and Balls Pyramid, Southwest Pacific Ocean

“…While geomorphology appears to be a useful surrogate for benthic assemblages for the mid-to outer-shelf features, benthic communities around the inner shelf appear to be strongly structured by the hydrodynamic regime [23,58,59]. Geomorphology is considered to be less useful as a surrogate in this zone, however terrain variables derived from the DEM, such as seafloor ruggedness, may provide useful proxies for explaining distribution of benthic assemblages.…”

The influence of irradiance on tolerance to high and low temperature stress exhibited by Symbiodinium in the coral, Pocillopora damicornis, from the high‐latitude reef of Lord Howe Island

“…1000 km from the southern GBR, and is home to the southernmost coral reef in the world. Despite the high-latitude conditions and geographic isolation of the Island, both symbiont and coral diversity are high (Table 1; Harriott et al 1995). Of particular note, Pocillopora damicornis hosts three novel C types (C100, C103, C118) at LHI (Table 1), but is known only to associate with types closely related to C1 (such as C1c, which differs by one base-pair), and D1 elsewhere in the Indo-Pacific (LaJeunesse et al 2003Sampayo et al 2007).…”