438 U. S. BUREAU OF FISHERIES 



Percentages. — Percentages are usually shown as whole numbers. 

 Fractions of per cents are dropped if less than five-tenths, and the 

 percentage is raised to the next higher integer if the fraction is greater 

 than five-tenths. If the fraction is exactly five-tenths, the integer is 

 raised or lowered to make it an even number. 



Converting. — Many of the figures shown in the statistical tables 

 published herewith have been reduced to thousands of pounds or 

 dollars. In making these conversions the largest number from which 

 a group of items is computed is raised or lowered to the nearest thou- 

 sands place. If the number ends in an even 500, the thousands 

 integer is raised or lowered to make it an even number. The indi- 

 vidual items are changed to conform to the total thus obtained. 



CONVERSION FACTORS 



It is the policy of the bureau to show the detailed catch figures of 

 all products in pounds for the sake of uniformity and for purposes of 

 comparison. Following such a policy presents very definite problems. 

 In the case of fish there is little difficulty since in very rare instances 

 are such products reported in units of measure other than pounds. 

 For shellfish, however, the units of measure may be bushels, sacks^ 

 barrels, or thousands of shellfish, gallons of meats, etc. These many 

 units make standardization difficult, but when coupled with the wide 

 variation in the requirements or definition of some of these units in the 

 various States the problem becomes even more complex. 



All bivalve mollusks are reported in pounds of meats in the detailed 

 catch tables presented in this report. In addition there is presented a 

 supplementary table for each section on the production in bushels. 

 These supplementary tables also give the production of certain other 

 shellfish, such as crabs, in number. 



Oysters. — Probably the greatest problem in presentation of fishery 

 statistics in uniform units of measure is in the case of oysters. 

 Usually the production of oysters on the Atlantic and Gulf coasts is 

 reported to bureau agents in bushels and prior to the data shown in 

 this report conversion from bushels to pounds of meats was effected 

 on the basis of a uniform yield of 7 pounds of meat to the bushel. 

 There follows a table which gives the results of a recent study of the 

 measures used for oysters in the various States and of the average 

 yields per bushel. This table presents the new factors that have been 

 used in the oyster statistics given in this report. These figures apply 

 to the year 1930 and are based on the records of oyster canneries and 

 shucking houses. It is probable that in subsequent years there will 

 be variations from these figures. 



