Survey : SLAN/6/1956 (part of CEFAS Historic surveys)

This survey was undertaken by Cefas as part of the CEFAS Historic surveys;

Station and biological data collected during research surveys carried out by
Cefas (formerly Directorate of Fisheries) in seas around the UK, mostly in the
North Sea, since 1902. The survey hauls are not laid out systematically as a
grid, as in current International Bottom Trawl Surveys (IBTS) and are widely
distributed over (especially) southern and central North Sea areas. Gears and
protocols were not standardised throughout, due to the long term nature of the
series. Surveys took place in each season. Data are lacking for the periods of
both World Wars. In some periods (e.g. the early 1900s), all species caught
were recorded, whereas in other periods (e.g. 1920s-30s), only the key
commercial species (e.g., Plaice, Sole and Cod) were recorded systematically.
Note that some surveys targeted particular species (notably Plaice).

Survey took place between 21/03/1956 and 29/03/1956 on Sir Lancelot

Equipment used during this survey :

- Otter trawl Codend catch

Survey operations were undertaken on 42 stations

36 different species were caught on this survey

本调查由英国食品标准局（Cefas，原渔业局）发起，作为其历史调查项目的一部分；该局自1902年以来在包括北海在内的英国周边海域进行了多项研究调查，其中大部分在北海区域。调查的渔获物并非以网格系统有序排列，如现行国际底拖网调查（IBTS）所示，而是广泛分布在北海的南部和中部区域。由于系列数据的长期性质，工具和协议并未在整个调查过程中实现标准化。调查在各个季节均有所开展。两次世界大战期间的数据缺失。在某些时期（例如20世纪初），记录了捕获的所有物种，而在其他时期（例如1920年代至1930年代），仅系统地记录了主要商业物种（例如比目鱼、鳎鱼和鳕鱼）。值得注意的是，某些调查专门针对特定物种（尤其是比目鱼）。1956年3月21日至3月29日，在“兰斯洛特爵士”号上进行了此次调查。此次调查使用的设备包括：

- 雪茄形拖网及网囊渔获物

调查在42个站点进行，共捕获了36种不同的物种。