The broadnose sevengill shark (Notorynchus cepedianus) is a common high trophic level predator around coastal New Zealand. Data on the ecology of the species in New Zealand are severely lacking and anthropogenic impacts are unquantified. To partially address this, we undertook a study of the demographics of a population at Stewart Island. Sampling trips were carried out seasonally from winter 2016 to spring 2017. A baited underwater video system (BUV) was deployed on 133 occasions (mean = 22.2 deployments per season) in a shallow coastal embayment to capture underwater video of N. cepedianus for photo-ID of individuals. N. cepedianus was detected on all but one deployment. Images extracted from video recorded the presence of 149 different individuals. Capture-recapture analysis of these data using robust design methods indicated a seasonal trend in abundance of the population using the study area, ranging from 34 (95% CI = 21 - 55) during winter 2016, to 94 (95% CI = 44 - 199) during spring 2017. This study presents the first data on demographic parameters of N. cepedianus in New Zealand.

中文翻译：

---

使用照片 ID 捕获-重新捕获估计阔鼻七鳃鲨 (Notorynchus cepedianus) 的种群参数

宽鼻七鳃鲨（Notorynchus cepedianus）是新西兰沿海常见的高营养级捕食者。关于新西兰物种生态的数据严重缺乏，人为影响也未量化。为了部分解决这个问题，我们对斯图尔特岛的人口统计数据进行了研究。从 2016 年冬季到 2017 年春季季节性地进行了采样旅行。在浅海岸海湾部署了 133 次（平均每季部署 22.2 次）的带诱饵水下视频系统 (BUV) 以捕获 N. cepedianus 的水下视频以供拍照。个人身份证。N. cepedianus 在除一次部署外的所有部署中都被检测到。从视频中提取的图像记录了 149 个不同个体的存在。