Survey : GEBL/D/1939 (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 15/02/1939 and 20/02/1939 on GBligh

Equipment used during this survey :

- Otter trawl Codend catch

Survey operations were undertaken on 6 stations

0 different species were caught on this survey

本调研由Cefas（原渔业局）发起，作为其历史调研计划的一部分。自1902年起，Cefas在英国周边海域（尤其是北海）开展了多次研究性调查，收集了站点和生物数据。这些调查捕获物并非按网格系统有序排列，如当前国际底拖网调查（IBTS）所示，而是广泛分布于北海南部和中部地区。由于该数据系列具有长期性质，因此在整个过程中，设备和协议并未标准化。调研在每个季节进行，两次世界大战期间的数据缺失。在某些时期（例如20世纪初），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），仅系统地记录了关键商业物种（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）。1939年2月15日至20日，在GBligh号上进行的调研中，使用了如下设备：

- 水獭拖网、网囊捕获物

此次调研在6个站点进行，共捕获0种不同物种。