310 THE SEAS 



they form a complete food in themselves, and an oyster 

 has been compared in food value to a glass of milk. More- 

 over, under the right conditions, great numbers can be 

 cultivated in comparatively small areas. Although not 

 yet applicable to the true fisheries, aquiculture or farming 

 of the products of the sea, has been shown to be a perfectly 

 practicable proposition when applied to shellfish, the 

 collection and sowing of the " seed " followed by care and 

 attention during growth, resulting in a rich harvest, some 

 idea of which will be gained from the following extract 

 from an official report of the Ministry of Agriculture and 

 Fisheries. 



" It has been calculated that an acre of the best mussel 

 ground will produce annually 40,000 lbs. of mussels, 

 equivalent to 10,000 lbs. of mussel meat with a " fuel " 

 value of 3,000,000 calories and a money value of about 

 ^250, and this at the cost of practically no capital ex- 

 penditure and only such labour as is involved in trans- 

 plantation to prevent over-crowding, and to secure the best 

 conditions for growth and fattening. No known system 

 of cultivation of agricultural land can produce correspond- 

 ing values in the form of animal food. The average 

 yield in beef of an acre of average pasture land is reckoned 

 to be 100 lbs., equivalent to 120,000 calories and valued 

 at, say, £y 10s. The yield of rich fattening pasture may 

 be as high as 190 lbs., equivalent to 480,000 calories, and 

 valued at, say, ^14. " 



Purification 



Unfortunately, there is one great drawback to the con- 

 sumption of shellfish ; the risk of bacterial infection. 

 Oysters and mussel beds are often situated in estuaries 

 many of which are badly contaminated by sewage brought 

 down from towns further up stream. Any bacteria there 



