H 



The level of the deep winter pond is now at a higher 

 level than that of the summer pond, so when the doors 

 separating these are raised a sufficient head of water is 

 obtained to induce an appreciable current from the deep 

 winter pond into the shallow summer one. The most 

 experienced hand superintends the operation and he has 

 need of all his skill for the volume of water available 

 used to produce the current is very limited and does not 

 permit of a long-continued How. The flow must not be 

 permitted to be too great or the winter pond will empty 

 so rapidly that an equilibrium of level between it and 

 the summer pond will be established long before a 

 proper proportion of the fish have all passed upwards. 

 Neither must the current be too weak for then the 

 fish will fail to be attracted towards it. The operation 

 is repeated until all the fish have passed into the deep 

 wintering ponds. By the time this transfer is completed 

 the shallow summer ponds, now denuded of fish, contain 

 little or no water except in the deep ditches along their 

 margins and in this dry condition they remain the whole 

 winter. This annual draining and exposure of the bed of 

 the summer ponds to atmospheric influence is an opera- 

 tion of prime importance to the continued prosperity of 

 these fish -farms. An instance of the fatal result attendent 

 upon the long-continued non-observance of this axiom of 

 pond-culture is detailed on page 46. A severe winter is 

 an anxious season for Arcachon fish farmers in spite of 

 all the precautions that can be taken. They fear parti- 

 cularly the cold dry wind from the north-east for a tempest 

 from that direction may so reduce the temperature of the 

 ponds that the stock of mullet and bass may be deci- 

 mated and even destroyed in a single night. During 

 ordinary frosty weather when ice forms over the ponds 

 care is taken to break holes in it at numerous intervals 

 to allow some facilities for aeration. 



Methods of capturing the Fish. 



When they have attained marketable size the fish 

 are caught as demand requires by one of two methods 

 according to the species that may be ordered. 

 Mullet, bass and eels are the only kinds which mature in 

 considerable numbers in the ponds and while the two 



