Long-term underwater images from around a single mooring site in McMurdo Sound, Antarctica (2017-2019)

Abstract: Long-term images taken by the camera from the McMurdo Oceanographic Observatory mooring in McMurdo Sound, Antarctica during its 2-year deployment (2017-2019). The mooring was situated at the seawater terminus of the McMurdo Station seawater intake jetty at 21 m deep, typically under thick sea ice cover. The automated 360° pan-tilt-zoom (ptz) camera, inside of an air-filled self-cleaning dome, was programmed to move to 42 ptz "waypoints" every hour and take a still 1920x1080 JPG image for archiving. Lights, oriented in one direction only, illuminated a rock/rubble slope for much of each winter, when there was no natural illumination. The camera was situated on a concrete block, which elevated the camera about 1m off of the seabed. Motile and sessile benthic biota, including notothenioid fishes, anemones, pycnogonids, asteroids, soft-corals, sponges, and nudibranchs are commonly seen in the images. Some ptz waypoints survey the water column and underside of the sea ice, capturing also the presence of larval/juvenile fishes and other plankton/nekton in the water column. Maximum intervals between subsequent images from the same ptz waypoint were about 1 hour, though many waypoints were captured at somewhat higher frequency. Interval images, taken at 5-min intervals irrespective of camera orientation, were also captured. Images are occasionally obscured/impacted by the camera dome's wiper, darkness, low visibility, minor fouling of the camera dome, and out-of-focus lens elements.

摘要：本数据集收录了南极麦克默多湾（McMurdo Sound）麦克默多海洋观测站锚系设备在2017至2019年为期两年的部署期间所拍摄的长期影像。该锚系布设于麦克默多站海水取水栈桥的海水终端位置，水深21米，通常处于厚海冰覆盖之下。安装于充气自清洁穹顶内的自动化360°云台变焦（pan-tilt-zoom, PTZ）相机，被预设为每小时遍历42个PTZ航点，并拍摄分辨率为1920×1080的JPG静态图像用于归档。单向定向灯光会在每个冬季的大部分时段照亮一处岩石/碎石斜坡——此时该海域无自然光照。相机固定于混凝土基座上，较海底抬高约1米。影像中常可观测到移动及固着底栖生物，包括南极鱼科（notothenioid）鱼类、海葵、海蜘蛛（pycnogonids）、海星（asteroids）、软珊瑚、海绵以及裸鳃类软体动物。部分PTZ航点会对水柱及海冰底面进行勘察，同时也能捕捉到水柱内幼鱼及其他浮游/自游生物（plankton/nekton）的踪迹。同一PTZ航点的后续影像最大间隔约为1小时，不过多数航点的拍摄频率相对更高。此外还会采集固定间隔为5分钟的连续影像，无需考虑相机当前朝向。影像偶尔会因相机穹顶雨刮器干扰、黑暗环境、低能见度、相机穹顶轻微附着污垢以及镜头元件失焦而被遮挡或画质受损。