PUBLIC FISHERIES FOR SHELLFISH 197 



really anxious to preserve as many of these little ones as possible. 

 As a rule the contents of the net are very rapidly sorted. But 

 when the catch is large the process is more tedious, and as space 

 in a shrimper is limited, part of the catch may be put into fish 

 baskets unsorted while the remainder is being dealt with. Under 

 such circumstances the young fish have practically no chance of 

 surviving. With long hauls, large catches and in warm weather 

 the mortality among the undersized fish is greatest. It is to be 

 feared that a large proportion of the immature fish taken in the 

 course of shrimp trawling is necessarily destroyed. 



Wherever shrimping is carried on there are regulations which 

 have for their object the minimising of this destruction. 



In the first place a fishing ground may be closed entirely or 

 during a part ot the year to shrimping, as, for example, the fishing 

 grounds off Blackpool. This method is quite effective, but if carried 

 too far may result in the extinction of the shrimping community. 

 Other regulations deal with the construction of the net. The 

 beam must not exceed 14 (Port of Southampton) or 25 ft. (Lancashire 

 and Western district). The shape of the net may be regulated. 

 In the Lancashire and Western district it is not permissible to use 

 a shrimp trawl if the length of the net measured from the centre of 

 the beam to the tail end exceeds one and a half times the length of 

 the beam. It is found that a greater length than this merely 

 faciUtates the capture of young fish and gives no increased yield 

 of shrimps. 



The size of the mesh is also regulated, for instance, in the Suffolk 

 and Essex district, a shrimp net may not have more than sixteen 

 meshes or thirty knots to the linear foot ; in the neighbouring 

 Kent and Essex district the regulation prescribes not more than 

 108 rows of knots to the linear yard. There does not seem much 

 object in a regulation of this kind since the largest mesh which will 

 capture a shrimp will also take a very small fish. Other regulations, 

 e.g. the Eastern district, prescribe that the net must be raised and 

 cleared not less than once in every half-hour, and the contents 

 forthwith sorted and sifted in the sea at a place where the water is 

 at the time not less than 6 in. in depth. This regulation is for 

 fishing otherwise than from a boat. In some cases shrimpers fishing 

 from a boat or cart must raise and clear the net once every hour. 

 The objection to a by-law of this kind is that a constant supervision 

 of every fisherman is necessary. 



The female shrimp, like the crab and lobster, carries its eggs under 

 the tail, but although the percentage of berried females to total 

 females may be as high as 74-9 per cent in May on the Lancashire 

 shrimping grounds, there seems no reason to anticipate a permanent 



