44 
Teil C - Annex 
2 Fish 
See table 2.1: Beam trawl/otter trawl surveys. 
Standard nets 
Equipment standard North Sea: Beam trawl 
According to StUK, a beam trawl with a beam length of 7 metres is specified as the standard 
net for fish fauna studies. Deviations from the standard are possible but have to be docu 
mented in a gear specification. 
The beam trawl consists of an iron beam with trawlheads and the net (fig. 4). The length of the 
net is 21.4 m, its circumference 19 m. It consists of an upper belly, wings, and lower belly. In 
formation about the net material cut and assembly is provided in fig. 5. The footrope of the net 
is a rope-wrapped chain. To catch also smaller fish, the codend is lined with an inside web 
bing (inner codend) with 18 mm mesh size (10 mm mesh bar). 
The iron trawl beam has a total length of 7.45 m; the clearance between the trawlheads is 
7.15 m. The height of the trawlheads on either side of the beam is 70 cm, exceeding the height 
of the beam by 15 cm, so that the beam is 55 cm above ground. Each trawlhead is 21 cm 
wide. 
5 tickler chains of different lengths are mounted in front of the mouth of the trawl. The chain 
length increases by 80 cm each from fore to aft (length of the first chain = 13.3 m). 
4 of Sin 
Figure 4: Beam trawl (sketch).