Point Shapefile of Bottom Photographs Acquired on Cruise SUN03002

Pulley Ridge is a series of drowned barrier islands that extends almost 200 km in 60-100 m water depths. This drowned ridge is located on the Florida Platform in the southeastern Gulf of Mexico about 250 km west of Cape Sable, Florida. This barrier island chain formed during the initial stage of the Holocene marine transgression. These islands were then submerged and left abandoned near the outer edge of the Florida Platform. The southern portion of Pulley Ridge hosts zooxanthellate scleractinian corals, green, red and brown macro algae, and a mix of deep and typically shallow-water tropical fishes. This reef community is in unusually deep water, and its extent and the controls on its distribution were unknown. To address these questions scientists from the U.S. Geological Survey Coastal and Marine Geology Program in cooperation with scientists from the University of South Florida Department of Marine Sciences have completed a detailed mapping of the southernmost 35 km of Pulley Ridge. The area was mapped using multibeam bathymetry, sidescan-sonar imagery, and high-resolution seismic-reflection profiling to define the geologic framework on which the reef is established. Submersible dives, remotely operated vehicle (ROV) transects, and transects of bottom photographs and video were collected to identify the corals and to map their distribution. This extensive suite of data has been compiled and preliminary analysis of the data suggests that the reefs are not tied to the ridge system, but instead are more broadly distributed. Whether reef distribution is controlled by oceanographic conditions or by subtle differences in the substrate that overlies the barrier island system is unclear, and are topics of continued research.普利岭（Pulley Ridge）是一系列沉没障壁岛，在60至100米的水深范围内延伸近200公里。该沉没海岭坐落于墨西哥湾东南部的佛罗里达陆架之上，距佛罗里达州萨布尔角以西约250公里。这套障壁岛链形成于全新世海侵初期，随后遭海水淹没并被遗弃在佛罗里达陆架外缘附近。普利岭南部区域栖息着含虫黄藻的石珊瑚（zooxanthellate scleractinian corals）、绿藻、红藻与褐藻等大型海藻（macro algae），以及深浅水热带鱼类的混合类群。该礁体群落所处水深异乎寻常，其分布范围与管控其分布的核心机制此前尚不明确。为解答上述科学问题，美国地质调查局（U.S. Geological Survey）海岸与海洋地质项目组与南佛罗里达大学海洋科学系的科研人员展开合作，完成了普利岭最南端35公里区段的详细测绘工作。研究团队采用多波束测深（multibeam bathymetry）、侧扫声呐影像（sidescan-sonar imagery）与高分辨率地震反射剖面（high-resolution seismic-reflection profiling）技术，明确了礁体赖以形成的地质基底框架；同时通过载人深潜作业、遥控水下机器人（remotely operated vehicle, ROV）断面调查、海底照片与视频采样，完成珊瑚类群识别与分布图谱绘制。该套海量观测数据已完成整合，初步分析结果显示，礁体并非局限于该海岭系统范围内，而是呈现更为广泛的分布特征。目前尚不清楚礁体分布是受海洋水文条件管控，还是受覆于障壁岛系统之上的海底基质细微差异影响，相关问题仍为后续研究的核心议题。