North Marine Region demersal fish and invertebrate collection records (DEW collation), Australia (1980 - 1997)

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.

本数据集收录了来自北部规划区的底栖鱼类拖网、底栖虾类拖网以及底栖生物滑橇采样器（epibenthic sled）所获取的底栖鱼类与无脊椎动物的渔获记录。
该数据集汇编了9次科研航次（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）的相关数据。
样本中各物种的渔获量分别以原始重量与计数、总重量与计数（原始值经子采样比例换算所得）以及单位面积重量与计数三种形式记录。物种以CAAB代码进行标识。样本属性包含航次、采样地点、采样时间、采样渔具以及采样区域。
本数据集由环境与水资源部（Department of the Environment and Water Resources, DEW）委托制作，用于在制定该区域海洋生物区域规划期间，对北部海洋区域进行特征剖析。所有航次的数据均整合至统一的表格集合中，采用一致的结构与计量单位。
本数据集的构建目标是为原始数据集提供便捷的访问途径——原始数据集此前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计数与重量计量单位进行呈现，但不同样本的数据不可直接视为具有可比性。具体而言，不同采样渔具对同一物种的可捕性存在差异。即便同一航次中使用相同类型渔具获取的样本，也未必具备相互可比性。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，对本数据集的分析仅可达到半定量级别。即便针对同一航次、同一渔具类型的样本，若要假设其具备可比性，也需参考航次报告进行验证。