224 BULLETIN OF THE BUREAU OF FISHERIES. 



Lankester, in his article on the Mollusca, published in the Encyclopedia Britan- 

 nica, states that in 1873 the mussels exported from Antwerp alone to Paris to be used 

 as a human food were valued at $1,400,000. If this production still continues, the 

 total yearly value of the mussel fishery for Belgium and France alone equals nearly 

 $2,000,000. 



Owing to the food shortage in Europe caused by the war, the boiling and salting 

 of mussels in Holland for German consumption has developed into a large and valuable 

 industry. According to the Seafood Journal for February 12, 191 7: 



Up to a month or two ago these humble shellfish which abound in the shallow waters of the Scheldt 

 delta were retailed for local consumption and constituted a cheap popular food. They have now sud- 

 denly disappeared from the market, and instead of being eaten are salted down in great quantities and 

 bought up for Germany. Some of the workmen's families that have taken up the new occupation are 

 earning about $6 a day, for them a princely wage. 



Consul Frank W. Mahin, of Amsterdam, also states in Commerce Reports No. 61, 

 Washington, D. C, Thursday, March 14, 191 8, page 963, that — 



Mussels abound in the vicinity of Texel, an island at the mouth of the Zuider Zee. They have been 

 eaten more or less, but now it is probable they will become very popular. Samples of smoked mussels 

 have been received from Texel, which are pronounced "uitstekend" (substantially, "delicious"). 

 Smoked and salted, the mussel is said to resemble smoked meat (similar to American dried beef), but 

 tenderer and fatter. 



These facts serve to show how important and valuable the mussel fishery is to 

 Europe and suggest the possibilities of developing an equally great food-producing 

 industry in this country from the abundance of natural mussel resources at our disposal 

 and the vast unutilized areas along our shores that are especially adapted for the culti- 

 vation of this particular shellfish. 



CHEMICAL COMPOSITION AND NUTRITIVE VALUE. 



Chemical analyses made by Atwater (1892), Atwater and Bryant (1906), and 

 Alsberg, whose account is published in Field (191 1), show that the sea mussel not only 

 contains the same kinds of nutrients as other shellfish but contains them in greater 

 abundance. These nutrients are: (1) Protein, which forms the nitrogenous basis of 

 blood, muscle, connective tissue, etc., and supplies energy to the body ; (2) carbohydrates; 

 (3) fats, which may be stored up as fat or consumed for fuel; and (4) mineral matters 

 or ash, which are used chiefly in the formation of bone. The energy-yielding power of 

 a nutritive substance is measured in terms of its fuel value, which refers to the number 

 of calories of heat equivalent to the energy that the body is supposed to obtain from 1 

 pound of the thoroughly digested food. A calorie as here used equals approximately 

 the amount of heat required to raise the temperature of 1 pound of water 4° F. Accord- 

 ing to the factors of Rubner, the fuel value of each pound of protein or carbohydrate is 

 equivalent to i,S6o calories of energy, while that of fat is equal to 4,220. 



Table 6 shows the comparative composition and fuel value of the mussel and several 

 shellfish most commonly found on the market. Of the five species the mussel ranks 

 first, second, and third, respectively, in the yield of carbohydrate, fat, and protein, 

 while in the total production of nutrients it surpasses all the others. Its superiority 

 over the oyster in this respect amounts to 365 per cent, and over the round and long 

 clams to 220 per cent and 1 1 per cent, respectively. The lobster most nearly approaches 



