Observations of seabirds in Macquarie Island waters (1999)

This survey is a first attempt at determining the distribution and relative abundance of all seabird species occurring in Macquarie Island waters, especially in relation to the main bathymetric and oceanographic features of the study area, namely the Macquarie Ridge and Subantarctic Front, respectively. To this end, observations of seabirds were made from aboard the CSIRO Research Vessel Southern Surveyor while it conducted acoustic, trawling and benthic surveys in the waters immediately round Macquarie Island and northwards along the Macquarie Ridge during 14-31 January 1999. The nine main sites within the study area and the distribution of seabird counts at each site are shown in Figure 1 (see Appendix 4 of https://www.frdc.com.au/project?id=1942). Most observations were made over the relatively shallow waters of the main part of the Macquarie Ridge i.e. close inshore off the east and west coasts of the island and northward along the ridge to the southern edge of the Subantartic Front Gap (sites 2-5). Additional observations were made in shallow waters well south of the island at the southernmost part of the ridge (site 7), and at two other ridge sites north of the Subantarctic Front Gap (sites 8 and 9). Observations were also carried out at two deep-water (pelagic) sites: at site 6 in waters c.25 miles west of Aurora Trough, and at the Subantarctic Front Gap (site 1) immediately north of the main north-south ridge through the island.

本调查系首次针对分布于麦夸里岛周边海域的全部海鸟物种的分布格局与相对丰度展开系统性梳理，重点解析其与研究区核心水深地形及海洋水文特征——分别对应麦夸里海岭（Macquarie Ridge）与亚南极锋（Subantarctic Front）——的关联。为此，研究团队于1999年1月14日至31日期间，搭乘联邦科学与工业研究组织（CSIRO）旗下科考船‘南部勘测号’（Southern Surveyor），在该船于麦夸里岛周边及沿麦夸里海岭向北延伸海域开展声学、拖网与底栖勘测的同时，完成了海鸟观测数据的采集。研究区内共设置9处主要观测站点，各站点的海鸟数量统计分布详见图1（具体信息可参见https://www.frdc.com.au/project?id=1942的附录4）。绝大多数观测工作开展于麦夸里海岭主体区域的相对浅水区，即紧邻该岛东西海岸的近岸海域，以及沿海岭向北延伸至亚南极锋缺口南缘的区域（站点2至5）。另有部分观测工作在该岛以南极远处的海岭最南端海域（站点7），以及亚南极锋缺口以北的另外两处海岭海域（站点8、9）完成。本研究还在两处深水（远洋（pelagic））站点开展了观测：其一为奥罗拉海槽（Aurora Trough）以西约25英里的海域（站点6），其二为横穿该岛的南北走向主海岭正北方的亚南极锋缺口区域（站点1）。