Survey : SLAN/16/1956 (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 04/10/1956 and 12/10/1956 on Sir Lancelot

Equipment used during this survey :

- Otter trawl Codend catch

Survey operations were undertaken on 20 stations

15 different species were caught on this survey

此次调查由Cefas（原渔业局）负责实施，作为其历史调查计划的一部分。自1902年起，Cefas在英国周边海域（尤其是北海）进行了多次研究调查，收集了站点和生物数据。与现行的国际底拖网调查（IBTS）不同，这些调查的渔获物并非按网格系统排列，而是广泛分布在北海南部和中部地区。由于该数据系列具有长期性，因此装备和协议并未在整个过程中实现标准化。调查在各个季节进行，两次世界大战期间的数据缺失。在某些时期（例如20世纪初），所有捕获的物种均被记录，而在其他时期（例如1920年代至1930年代），仅系统地记录了关键的商业物种（例如鳎鱼、鳎鱼和鳕鱼）。值得注意的是，某些调查专门针对特定物种（尤其是鳎鱼）。1956年10月4日至12月10日，在Sir Lancelot号上进行的调查中，使用了如下设备：- 海獭拖网渔获物网。此次调查在20个站点进行，共捕获了15种不同的物种。