134 MARVELS OF FISH LIFE 
the trawl. The net itself is cone-shaped, and the end 
of the cone, known as the “cod end” is open, in order 
to let the fish out. When being fished the cod end of 
the trawl is tied up with rope. 
In the otter trawl, the beam is dispensed with, and 
the mouth of the net is kept open by means of two 
“otter boards.” These boards may be six to seven feet 
high and three feet wide. To the top of each board is 
attached the head line, and to the bottom the ground 
line. In large trawls the head line may be one hundred 
feet in length, while the ground line is half as long 
again. The trawl is hauled by two steel wire ropes, 
often a mile in length. Each rope is attached to 
an otter board in such a manner that as the vessel 
advances, the boards incline outwards from the 
mouth of the trawl. Thus the rush of water forces 
these two boards apart, and the mouth of the net is 
kept open. 
The “ harvest of the sea ”’ is a term with which most 
of us are familiar. But the term isa misnomer. Harvest 
implies that man sows and reaps the result of his labours. 
In the sea Nature sows, and man in gathering the crop 
does immense harm to the supply in the future by the 
destruction of immature fish. 
Round fishes, in consequence of their habits, have 
not suffered to the same extent as the fishes that live 
on the bottom, nevertheless, the North Sea is gradually 
being emptied of its fish life, and in consequence the 
fisherman has to go farther afield. It is smail matter for 
