MIGRATION OF FISH 99 



travels over the deeper seabeds where 

 there are few eggs except those of the 

 herring, and where the sea-meadows soon 

 recover from the onslaught of the trawl, 

 since, like the plough, it fertilizes the sea- 

 bed by stirring up the soil or sand, although 

 the trawler does not plough the seabed as 

 much as some people would imagine. 



Often we are told that when the war is 

 over the debris of wrecks at the bottom of 

 the North Sea will be so great that the 

 trawls will be continually destroyed. 

 Considering the area of the North Sea and 

 the 600 trawlers sailing out of Grimsby 

 by far the largest centre it will be found 

 that, allowing a width of 70 feet for the 

 trawl, and a continual trawling period of 

 say 300 days per annum, the vessels will 

 cover the full area of the North Sea only 

 once a year, although those fishing banks, 

 of course, receive greater attention which 

 by the greater quantities of fish attract 

 the fishermen most. Thus unless a wreck 

 is in the midst of a heavily fished 

 bank, it will seldom be touched by the 

 trawl. 



It is a mistake to imagine that the 



