Nephrops Underwater TV Survey FU16 Porcupine Bank

<i>Nephrops norvegicus</i> are common around the Irish coast, occurring in geographically distinct sandy or muddy areas where the sediment is suitable for construction of their burrow dwellings. This dataset provides quality assured estimates of <i>Nephrops</i> burrow densities from a randomised isometric grid of underwater television (UWTV) stations at six nautical mile spacing over the known spatial and bathymetric distribution of the FU (functional unit) 16: Porcupine Bank (illustrative shapefile provided with data). This dataset covers the period of 2012 and is ongoing. One hundred percent of the survey grid was covered in all years but 2012, where sixty-nine percent of the grid was covered (47 stations), and 2015, where no survey data are available due to research vessel breakdown. Dataset fields are Nephrops Functional Unit Number; Nephrops Ground Name; Survey Code; Year; UWTV Station number; Decimalised longitude and latitude midpoint of the UWTV station track; Adjusted density (Nephrops burrows/m²) ;Length in metres of the UWTV station track; Source of length data (USBL sled GPS, SHIP GPS, estimated GPS);Field of View in metres of camera system; Data Extraction source (SQL, MSAccess); Research Vessel Name; Correction Factor (Density / Correction Factor = Adjusted Density) and Depth (metres). Underwater TV Survey reports for this Nephrops stock are available at:http://hdl.handle.net/10793/1431 Also available is the ICES Cooperative Research Reports which details use of UWTV surveys to assess Nephrops stocks. Further details of stock assessment can found by accessing the following report: https://tinyurl.com/ices-nephrops

挪威龙虾（*Nephrops norvegicus*）常见于爱尔兰周边海域，栖息于地理分隔明确的沙质或泥质海底生境，此类沉积物环境适宜其挖掘洞穴居所。本数据集提供了经质量管控的挪威龙虾（Nephrops）洞穴密度估算值，数据源自以6海里为间距布设的随机等距水下电视（Underwater Television, UWTV）监测站位网格，覆盖了功能单元（FU）16号：波旁海台（Porcupine Bank）已知的空间与水深分布范围（数据附带该区域的示意性形状文件）。本数据集的调研始于2012年，目前仍在持续推进。除2012年仅完成69%的网格覆盖（共47个监测站位）以及2015年因研究船故障未获取任何调查数据外，其余年份均完成了100%的调研网格覆盖。数据集包含以下字段：挪威龙虾功能单元编号、挪威龙虾作业海域名称、调查代码、调查年份、水下电视监测站位编号、水下电视监测站位航迹中点的十进制度格式经纬度、校正后密度（单位：挪威龙虾洞穴/平方米）、水下电视监测站位航迹长度（单位：米）、航迹长度数据来源（USBL拖曳式GPS、船载GPS、估算GPS）、摄像系统视场范围（单位：米）、数据提取来源（SQL、Microsoft Access）、研究船名称、校正因子（密度/校正因子=校正后密度）以及水深（单位：米）。本挪威龙虾种群的水下电视调查报告可通过以下链接获取：http://hdl.handle.net/10793/1431。另有《ICES合作研究报告》详细阐述了利用水下电视调查评估挪威龙虾种群的方法。如需了解更多种群评估相关细节，可访问以下报告链接：https://tinyurl.com/ices-nephrops