Corals and coral communities of Lord Howe Island, Australia

Ecological and taxonomic surveys of hermatypic scleractinian corals were carried out at approximately 100 sites around Lord Howe Island. Sixty-six of these sites were located on reefs in the lagoon, which extends for two-thirds of the length of the island on the western side. Each survey site consisted of a section of reef surface, which appeared to be topographically and faunistically homogeneous. The dimensions of the sites surveyed were generally of the order of 20m by 20m. Where possible, sites were arranged contiguously along a band up the reef slope and across the flat. The cover of each species was graded on a five-point scale of percentage relative cover. Other site attributes recorded were depth (minimum and maximum corrected to datum), slope (estimated), substrate type, total estimated cover of soft coral and algae (macroscopic and encrusting coralline). Coral data from the lagoon and its reef (66 sites) were used to define a small number of site groups which characterize most of this area.Throughout the survey, corals of taxonomic interest or difficulty were collected, and an extensive photographic record was made to augment survey data. A collection of the full range of form of all coral species was made during the survey and an identified reference series was deposited in the Australian Museum.In addition, less detailed descriptive data pertaining to coral communities and topography were recorded on 12 reconnaissance transects, the authors recording changes seen while being towed behind a boat. The purpose of this study was to describe the corals of Lord Howe Island (the southernmost Indo-Pacific reef) at species and community level using methods that would allow differentiation of community types and allow comparisons with coral communities in other geographic locations.本研究在豪勋爵岛周边约100个点位开展了造礁石珊瑚（hermatypic scleractinian corals）的生态与分类学调查。其中66个点位位于岛屿西侧、占总长三分之二的泻湖礁体之上。每个调查点位均为一块在地形与动物区系上均一的礁面区域，尺寸通常为20米×20米左右。若条件允许，点位沿礁坡向上并跨越平坦区域布设为连续带状。各珊瑚物种的盖度采用五分制相对盖度百分比进行分级记录。本次调查还记录了其他点位属性：包括校正至基准面的水深极值、估算的坡度、底质类型，以及软珊瑚与大型、钙化结壳藻类的总估算盖度。研究人员利用泻湖及其礁体的66个点位的珊瑚数据，定义了可表征该区域绝大多数生境的少量点位类群。在整个调查过程中，研究人员采集了具有分类学研究价值或鉴定难度较高的珊瑚样本，并拍摄了大量影像资料以补充调查数据。本次调查还收集了所有珊瑚物种的完整形态系列标本，并将已鉴定的参考标本馆藏于澳大利亚博物馆（Australian Museum）。此外，研究人员还通过被船只拖曳的方式，在12条勘察样带上记录了精度稍低的珊瑚群落与地形描述数据。本研究的目的为：在物种与群落层面描述豪勋爵岛——印度-太平洋最南端的礁体区域——的珊瑚类群，所用方法可实现群落类型的区分，并可与其他地理区域的珊瑚群落进行对比。