OYSTEE AND MUSSEL EEPOET. Ill 



Great numbers of the oysters bred and reared through 

 their early stages at Arcachon are sent to Marennes and 

 La Tremblade, when from one to two years old, to be 

 fattened in a " pare d'elevage " and " greened " by feeding 

 upon the diatom Navicula fusiformis, var. ostrearia. 

 (See further on in this report under Marennes, p. 112 ; 

 and also under General Conclusions, p. 129). 



Koyan. 



This place is situated at the mouth of the Gironde, and 

 is a centre of the sardine fishing. I found there a fleet of 

 between 60 and 70 fishing boats carrying a trawl with a 

 beam of about 20 feet. Shrimping also is carried on by 

 means of fixed or suspended nets worked both from the 

 long breakwater and also from the boats. The net is 

 shaped as a shallow bag and is about 6 feet in diameter. 

 It has either a hoop round the mouth or is attached to 

 four light spars set in the form of a square. This frame- 

 work is then suspended by a rope which passes over a 

 pulley at the end of a long pole, on the breakwater, or a 

 light boom, on the boat, set at such an angle that the net 

 can be conveniently lowered into the water. Some bait 

 is put in the centre of the net and after it has been down 

 a short time it is hauled up rapidly and the shrimps are 

 thus caught in the concavity of the net. 



On the rocks to the north of Eoyan I found many small 

 natural oysters which the people go out at low tide to 

 collect, and to eat largely on the spot. The rocks here 

 are a richly fossiliferous limestone (cretaceous), and the 

 oysters seem to have rather thick, irregular, sometimes 

 distorted shells. Most of them adhere completely by one 

 valve, and are attached to the rocks in fair abundance 

 from low water mark up to at least half tide. They seem 

 to be mostly 2 or 3 years old, and are not really good to eat, 



