36 FISHERIES OF THE NORTH SEA 



there is a continental shelf of high land 

 under the Atlantic. With the abysmal 

 depths of the ocean on either side, this 

 ridge runs from the North of Scotland to 

 the Faroe Islands, intercepted by only one 

 narrow passage of deep water the Faroe 

 Channel. The high land continues to the 

 north-west, where the shelf again broadens 

 and sustains Iceland and the Iceland 

 banks. This submerged mountain chain is 

 called the Wyville-Thomson ridge, after 

 the discoverer who found it during the 

 famous Challenger expedition. On the 

 higher regions of these banks the British 

 trawler has developed a prolific fishery 

 during the past thirty years. Originally 

 the trawler could fish only in a depth of 

 about 40 or 50 fathoms the North Sea. 

 With the introduction of steam it was 

 possible to increase the size of the trawl 

 and the depth at which it could be. used, 

 and when the Dogger Banks showed signs 

 of being over-fished the ships went farther 

 north. Going through the Pentland Firth 

 in a north-westerly direction they followed 

 the bed of the Wyville-Thomson ridge and 

 found on the sandy banks, in the shallow 



