Table 39. — Yield of market orjsiers 1960, pounds of meat 



in U.S. standard bushel 



[From Power, 1962] 



Maine -- 7.50 



Massachusetts 6.50 



Rhode Island __ 7.00 



Connecticut.. 7. 70 



New York 7.50 



New Jersey 7.01 



Delaware 6.60 



Maryland 4.58 



Virginia 4. 19 



North Carolina 4.21 



South CaroUna 2.93 



Georgia 3. 15 



Florida, east coast 4. 20 



Florida, west coast 4.22 



Alabama 4. 17 



Mississippi... 3.86 



Louisiana 4.54 



Tc.tas. 5.07 



oysters were taken, but the problem requires 

 further study. 



Variations in the chemical composition of the 

 meat of 0. eduiis are similar to those which take 

 place in C. virginica. Gaarder and Alvasker 

 (1941) give a detailed account of these changes in 

 the oysters of Norwegian waters. The e.xtent of 

 annual fluctuations that took place in 1936 are 

 given in table 40. 



Table 40. — Extent of changes in the chemical composition 



of Ostrea eduiis in A^orway in percentage of ivet weight 



[According to Gaarder and Alvasker, 1941] 



In a comparison with the analysis of C. virginica, 

 the 0. eduiis has a relatively higher carbohydrate- 

 protein ratio and higher fat content. This may 

 be due primarily to the fact that European oysters 

 are grown on oyster farms while the sample of 

 southern American oysters was taken from wild 

 populations. Like\vise, the higher yields of ('. 

 virginica in the waters of northern latitudes is 

 primarily the result of skill in cultivation by 

 private oyster growers of New England and the 

 North Atlantic states rather than geography. 



INORGANIC CONSTITUENTS 



The mineral content of the edible portion of the 

 oyster consists primarily of sodium chloride (fig. 

 356), but it also contains almost every chemical 

 element present in sea water. Spectrographic 

 analysis of 22 samples of oyster ash (exclusive of 

 shell) made by the U.S. Bureau of Mines in 1940 

 at the request of the Bm-eau of Fisheries (data 

 on file in the library of the Bureau of Commercial 

 Fisheries Biological Laboratory, Woods Hole, 

 Massachusetts) showed that the samples consisted 

 mainly of sodium, potassium, calcium, magnesium, 

 and phosphorus; and low concentrations of the 



following elements: copper, iron, sihcone, alumi- 

 num, strontium, lithium, rubidium, nickel, silver, 

 titanium, zinc, vanadium, platinum, manganese, 

 gold, and zirconium. The results are predictable 

 since sea water which contains these elements 

 enters the composition of the oyster's body fluids. 



IODINE 



The presence of iodine in various sea food 

 animals has been generally knowm for a long 

 time and has been studied primarily from the 

 point of view of dietitians and nutritionists. 

 Coulson (1934) found that one average serving 

 of (\ virginica (110 g.) would furnish to the diet 

 54 /ig. of iodine, an amount higher than that 

 found in one serving of red salmon, milk, various 

 vegetables, and beef. The iodine content of fresh 

 oysters handled in the usual commercial manner 

 varied from 1,000 to 11,530 parts per billion on 

 the dry basis, or from 194 to 1,652 parts per biUion 

 on tlie original wet weight basis. When the 

 means of individual variation are considered 

 statistically, there appears to be no significant 

 variation in the iodine content of oysters from 

 different Atlantic and Gulf states nor any signif- 

 icant variation with season. There is, however, 

 a significant difference between the Atlantic and 

 Pacific Coast oysters, {C. drginica and 0. lurida): 

 the Pacific species have a lower iodine content 

 than the Atlantic species. The mode of accumu- 

 lation of iodine in the oyster tissue and the role 

 it plays in the physiology of the oyster are not 

 known. 



The iodine content in oyster meat can be arti- 

 ficially increased by placing live oysters in sea 

 water to which free iodine has been added. In 

 e.xperiments with C. angulata at Arcachon, France, 

 Loubatie (1931) showed that the concentration 

 of iodine in the tissues of oysters increased 700 

 times over its normal value after live oysters 

 were kept for 4 days in water containing up to 

 3 mg./l. of free iodine. In 1932 a commercial 

 concern at Bordeaux, France, artificially produced 

 such "super-iodized" oysters and advertised 

 their beneficial effect in cases of anemia and other 

 maladies attributed to iodine deficiency. When 

 I visited Arcachon in 1932 there was apparently 

 a good demand for these oysters, which had a 

 strong iodine flavor. 



HEAVY METALS 



The ability to accumulate various elements 

 present in sea water at very low concentrations 



CHEMICAL COMPOSITION 



383 



