STATISTICS OF NORTH AMEIIICAN HAUDOCK FISHERY 35 



Table 5. — New England otter-trawl fishery for haddock 



1 Including 1 from New York for part of the year. 



2 Including 2 from New York for part of the year. 



3 Averages of figures calculated for each year. 



* Average number of trips divided by average number of trawlers. 

 5 Average total catch divided by average number of trawlers. 



The extent to which the above data indicate changes in the abun- 

 dance of the fish is very doubtful. The increased catch per trip is 

 rather an indication of a change in the nature of the trawlers enabling 

 them to make longer trips. This is borne out by the decreased num- 

 ber of trips made by a trawler each year. The catch per trawler 

 is probably the nearest approach to the catch per unit of fishing 

 effort, which is our only criterion of the relative abundance of the 

 fish. But we have just pointed out one change in the mode of opera- 

 tion, and others are probable both in the fishing ability of the average 

 traAvler and in the average length of time spent in fishing each 

 year. These changes influence the catch per trawler and make it 

 unreliable as an indication of the abundance of the fish. 



CHANGES IN THE DISTRIBUTION OF THE CATCH OF THE BOSTON 

 AND GLOUCESTER VESSEL FISHERIES 



In Table 6 the geographical distribution of the Boston and 

 Gloucester vessel fisheries is summarized for two periods — 1891 to 

 1901 and 1916 to 1925, both inclusive. The grounds east and west 

 of 66° west longitude are totalized separately. 



