North Marine Region demersal fish and invertebrate collection records (DEW collation)

The dataset comprises catch records of demersal fish and invertebrates from demersal fish trawls, demersal prawn trawls and epibenthic sled samples from the Northern Planning Region. It is a compilation of data from 9 research voyages (SO 05/80, SO 07/80, SO 02/81, SS 03/90, SS 05/91, SS 01/93, SS 02/97, SS 08/97and SS 03/98). The catch of each species in a sample is recorded as raw weight and count, gross weight and count (raw values divided by the subsampling fraction) and per area weight and count. Species are recorded as CAAB codes. Sample attributes include the voyage, location, time, sampling gear and sampled area. The dataset was created for the Department of the Environment and Water Resources (DEW) for use in profiling of the North Marine Region during the development of a marine bioregional plan for the region. Data from all voyages are in a single set of tables and in the same structure and measurement units. The aim of the dataset is to provide convenient access to the data from the source datasets, which were stored in various data structures in various locations. Although the data are presented in uniform measurement units of counts and weights per unit area, data from different samples cannot be assumed to be comparable. In particular, the catchability of a species varies among types of sampling gears. Even samples from a given gear type on a given voyage may not all be comparable to one another. For example, gear may be altered during a voyage (e.g. multiple codend mesh sizes may be tried) and fish trawls are occasionally aimed at fish visible on the echo sounder. The data should therefore be analysed no more than semi-quantitatively. Assumptions on the comparability of samples -- even from a single voyage and gear type -- should be based on reference to the voyage reports.

本数据集涵盖北部规划区域的底栖鱼类（demersal fish）与无脊椎动物（invertebrates）渔获记录，数据来源于底栖鱼类拖网、底栖虾类拖网及近底拖网采样器（epibenthic sled）采集的样本。数据集整合了9个科考航次的相关数据，分别为SO 05/80、SO 07/80、SO 02/81、SS 03/90、SS 05/91、SS 01/93、SS 02/97、SS 08/97及SS 03/98。样本中各物种的渔获量以原始重量与个体数量、总重量与个体数量（原始值除以分样比例所得）以及单位面积重量与个体数量三种形式记录。物种信息以澳大利亚鱼类与海洋无脊椎动物物种编码（CAAB codes）标注。采样属性包含航次、采样站位、时间、采样渔具及采样区域。本数据集由环境与水资源部（Department of the Environment and Water Resources, DEW）委托构建，用于该区域海洋生物区域规划编制过程中北部海洋海区的特征梳理工作。所有航次的数据均整合至统一的表格集合中，采用一致的数据结构与度量单位。本数据集的构建目标是为用户提供便捷获取源数据的途径——此前源数据集以不同的数据结构存储于不同位置。尽管本数据集采用统一的单位面积个体数量与重量作为度量标准，但不同采样点的数据不可直接视为可比较。具体而言，不同采样渔具对同一物种的可捕性存在差异；即便是同一航次中使用同一类型渔具获取的采样数据，也未必完全具备可比性。例如，航次期间可能会对渔具进行调整（如尝试不同的网囊网目尺寸），且鱼类拖网作业有时会针对回声测深仪探测到的鱼群开展。因此，本数据集仅可进行半定量分析。若要假设采样数据具备可比性（即便来自同一航次与同一渔具类型），均需参考对应航次的调查报告予以佐证。