FISHERY INDUSTRIES OF THE UNITED STATES, 1930 551 



COMPILATION PRACTICES 



Certain practices of importance used in the compilation of fishery 

 statistics are explained below: 



Days absent.- — In computing "days absent" for vessels landing 

 fares at the various ports, the day of departure and the day of arrival 

 are included; thus, a vessel leaving port on the 8th of the month and 

 returning on the 15th of the month will be shown as being absent 

 eight days. 



Operating units. — Operating units as referred to in this document 

 include persons engaged and fishing craft and gear employed. 



Vessels. — The term "vessels" refers to craft having a capacity of 

 5 net tons or greater. 



Incidental catch.- — ^The term "incidental catch" refers to the catch 

 of certain species by a type of gear which ordinarily does take ap- 

 preciable amounts, if any, of such species. 



Percentages. — Percentages are usually shown as whole numbers. 

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

 centage 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 individual items 

 are changed to conform to the total thus obtained. 



Conversion factors. — The principal conversion factors that have 

 been used in this report are as follows: 



Alewives To convert number of fish to weight in pounds 



multiply by 0.4. 

 Clams, hard To convert bushels to pounds of meat multi- 

 ply by 8. 

 Clams, soft To convert bushels to pounds of meat multi- 

 ply by 10. 

 Cod, large, salted To convert to fresh-gutted weight multiply 



by 1.90. 

 Cod, market, salted To convert to fresh-gutted weight multiply 



by 1.94. 

 Cod, scrod, salted To convert to fresh-gutted weight multiply 



by 1.98. 



Cod, all sizes, fresh gutted To convert to round weight multiply by 1.25. 



Crabs, blue (hard and soft) To convert number of crabs to weight in 



pounds multiply by 0.333. 

 Cusk, salted To convert to fresh-gutted weight multiply 



by 1.90. 

 Haddock, large, salted To convert to fresh-gutted weight multiply 



by 2.06. 

 Haddock, scrod, salted To convert to fresh-gutted weight multiply 



by 2.10. 

 Haddock, fresh-gutted, all sizes _ To convert to round weight multiply by 1.25. 

 Hake, large, salted To convert to fresh-gutted weight multiply 



by 1.90. 

 Hake, small, salted To convert to fresh-gutted weight multiply 



by 1.98. 

 Halibut, salted To convert to fresh-gutted weight multiply 



by 2. 



Herring, salted To convert to round weight multiply by 1.50. 



Mackerel, salted To convert to round weight multiply by 1.35. 



