Camera Surveys of the Subtidal Flora of Nova Scotia and Southwest New Brunswick 2022-2023

To assess the current distribution of kelp beds and other macroalgae in Nova Scotia and Southwest New Brunswick, subtidal drop camera surveys were performed from 2022-2023 at 140 sites. For each site, a GoPro HERO 10 camera was towed along a deep (7-12m) and shallow (3-5m) depth contour until 20 images were acquired per depth. Where possible, species were identified from photos, with particular care given to kelps (defined here as orders Laminariales and Tilopteridales) and fucoids (order Fucales). Crust-forming algae was not counted. Percent cover was calculated using a 10x10 point grid overlaid on each image and recording the dominant cover type at each point. The depth (in meters) of each photo after correcting for tide height ranged from ~0.5m to ~12m. Depths were corrected to chart datum (lowest astronomical tide) using tide predictions from the nearest tide station, taken from tides.gc.ca. Sampling was performed between July and October.为评估新斯科舍省与新不伦瑞克省西南部的海带床及其他大型藻类的当前分布状况，研究团队于2022至2023年间在140个采样点开展了拖曳式潮下带相机调查。每个采样点均沿7-12米深的深水等高线与3-5米深的浅水等高线拖曳GoPro HERO 10相机进行拍摄，直至每个深度层级均采集到20张图像。在条件允许的情况下，研究人员将依据照片对物种进行鉴定，重点关注海带类（本研究定义为海带目（Laminariales）与翅藻藻目（Tilopteridales））以及墨角藻类（墨角藻目（Fucales）），且未将结壳藻类纳入统计范畴。通过在每张图像上叠加10×10的点网格，记录每个网格点的优势覆盖类型，以此计算藻类的百分盖度。每张照片对应的水深（单位：米）经潮高校正后介于约0.5米至约12米之间。校正过程以最近验潮站的潮汐预报数据为依据（数据取自tides.gc.ca网站），将实测水深统一修正至海图基准面（最低天文潮位）。本次采样工作于7月至10月间开展。