the Bureau of Fisheries and of annual 

 pound net catch statistics by the States. 

 The States were often surveyed in dif- 

 ferent years so that the catches in each 

 State are not always available every year. 

 For this reason the changes in total 

 yield of each State will be discussed sep- 

 arately. 



SUMMER FISHERY 



Statistics of the Fishery, New Jersey 



Changes in total yield. — It is evident 

 chat the total yield has undergone major 

 fluctuations (table 1). The data do not, how- 

 ever, reveal reliable information on the 

 changes in gear, either as to amount or type; 

 and since these often are a principal cause 

 of changes in catch, the lack of accurate 

 records of gear injects some doubt and dif- 

 ficulty in interpreting the changes in yield 

 in terms of changes in abundance. In addition, 

 the records of catch are subject to some in- 

 accuracy because many of the data, espe- 

 cially in the earlier years of the Bureau's 

 canvasses, were obtained from operators who 

 lacked written records and based their fig- 

 ures on memory. Nevertheless, it is believed 

 that the Bureau's statistics, though not reveal- 

 ing the absolute values of the changes in the 

 yield, are sufficiently reliable to reveal major 

 changes that have occurred. 



The catch of scup in New Jersey by the 

 three principal types of gear (pound nets, otter 

 trawls, purse seines) was small from 

 1890 to 1892. It increased beginning in 1897, 

 reached a peak in 1929, and remained high 

 to 1933. From 1890 to about 1908, the fishery 

 expanded, mainly by increases in numbers 

 of ocean pound nets, especially in the southern 

 and later in the central seaboard counties of 

 the State. Since 1908, the number of these 

 nets has remained about the same although 

 there have been minor changes from year to 

 year. Other changes in gear resulting in an 

 increase in the catch were the expansion of 

 the purse seine fishery about 1920 and the 

 otter trawl fishery (especially in the winter) 

 beginning in 1929. 



Measurement of fluctuations. 



■In 



the present study, the pound net fishery in New 

 Jersey has been chosen for an analysis of 

 changes in abundance because it produces the 

 most important part of the total yield of scup 

 and provides a convenient unit for measuring 

 the relative abundance and availability of the 

 fish. There were certain factors that made 

 it difficult to obtain from these pound net 

 records a clear understanding of the causes 

 of fluctuations in the yield. These included 

 changes in availability by erratic movements 

 of fish, the lack of accurate and complete 

 records of the quantities of small fish dis- 

 carded at sea in times of unusual abundance 

 and low market, and changes in fishing effort 

 through destruction of gear or curtailment of 

 fishing during storms. Few operators kept 

 written accounts of the storm periods and of 

 the number of nets destroyed or damaged. 

 Changes in the amount of fishing also occurred 

 when fouled nets were changed at different 

 times of the season by being removed com- 

 pletely from the water, or, as in some dis- 

 tricts, by being hung on the pound- poles to 

 dry for a few days. Few records contained 

 notations of the actual number of nets fishing 

 during such periods of drying or changing 

 gear. 



Despite these influencing factors, a unit of 

 measure termed the catch per trap per season 

 was computed. This unit represents the num- 

 ber of pounds of scup caught by an average 

 trap in one season. In the analysis of the 

 causes of changes in the catch of the stationary 

 gear, the term "trap" will be used to refer 

 to both pound nets and floating traps, because 

 both gears are fundamentally the same in 

 construction and operation, and changes in 

 their catches are affected by the same or 

 similar causes. The measure was fairly 

 indicative of changes in abundance or in 

 availability and could be used for showing 

 relative changes in yield of the pound net 

 fishery of New Jersey. This gear produced 

 most of the catch in the State; therefore, its 

 catch reflected the major changes in total 

 yield. 



12 



