NICHOLSON; ATLANTIC MENHADEN PURSE-SEINE FISHERY 



In the Middle Atlantic area vessels ranged 

 from class 2 to 6, but no more than two classes 

 occurred at any port. At Port Monmouth and 

 Tuckerton, class 6 vessels did not show sub- 

 stantially greater catches per week than class 5 

 vessels. Class 5 vessels at Lewes clearly had 

 greater catches per week than class 3 vessels, 

 while class 5 vessels at Wildwood had greater 

 catches per week than class 2 vessels. 



Because the increases in the catch per vessel 

 week that accompanied the increases in vessel 

 carrying capacity were small and inconsistent 

 and the variability between ports was great, no 

 vessel class was designated as a standard for the 

 fishery. Effort was simply left unadjusted at 

 all excejst five ports — Lewes, Wildwood, Point 

 Judith, Gloucester, and Portland. 



Effort at Lewes and Wildwood was adjusted 

 because the differences in the catch per unit of 

 effort between the two classes at each port were 

 large. At these ports the 10-year mean of the 

 ratio of the catch per week of the group of larger 

 vessels to that of the group of smaller vessels 

 was computed for 1950-59. Annual effort of 

 the smaller vessels was adjusted by multiplying 

 the total number of weeks fished each year by 

 the mean ratio, 0.610 for Wildwood and 0.573 

 for Lewes. 



Efl^ort at the other three ports was adjusted 

 because many of the vessels, which were small 

 to medium-size otter trawlers temporarily con- 

 verted to purse seinei's during the summer, fished 

 intermittently, usually only when menhaden were 

 plentiful. Because effoi't could not be measured 

 very precisely under these conditions, it was esti- 

 mated in terms of Amagansett units by dividing 

 the annual catches at these ports by the mean 

 catch per week of Amagansett vessels. 



Most menhaden vessels were class 3, 4, or 5. 

 At most ports the relative proportions of one 

 class to another changed very little each year and 

 the number of vessels remained fairly constant 

 (Table 5). LTnder such conditions the number 

 of vessel weeks, with minor adjustments, was 

 as precise an estimate of total fishing effort as 

 was possible to obtain. Various other adjust- 

 ments might have been made, but with doubtful 

 improvement in the overall estimate of fishing 

 effort. 



Henceforth, vessel weeks will refer to units of 

 fishing eflfort and will include these adjustments. 



NUMBER OF VESSEL WEEKS 



After World War II ended in 1945, the number 

 of vessel weeks rose shar]5ly in the Chesapeake 

 Bay, Middle Atlantic, and North Atlantic areas 

 (Table 6) . The increase resulted from the addi- 

 tion of vessels in all areas and from an increase 

 in the number of weeks that plants in the North 

 and Middle Atlantic operated. 



After 1959 in the North Atlantic and 1962 in 

 the Middle Atlantic, the number of vessel weeks 

 droi)iied sharjjly. Much of the deci'ease in the 

 North Atlantic between 1959 and 1962 can be 

 attributed to a reduced number of converted 

 trawlers at Portland, Gloucester, and Point Ju- 

 dith, where no menhaden were landed after 1962. 

 After 1962 the number of vessels at Amagansett 

 also declined. Reduced effort in the Middle At- 

 lantic after 1962 was due to a decrease in the 

 number of vessels. The Tuckerton plant and one 

 of the Lewes plants closed during the 1964 season 

 and never reopened. The Wildwood plant op- 

 erated only a few weeks each year after 1964, 

 and the boats were transferred to plants in Ches- 

 apeake Bay. The remaining plant at Lewes 

 closed after the 1965 season. 



Effort in the Chesapeake Bay area fluctuated 

 between approximately 300 and 400 vessel weeks 

 from 1944 to 1954; thereafter it generally in- 

 creased (except when fishing was restricted in 

 1960 because of a poor market) until about 800 

 vessel weeks were reached in 1964-66. Addi- 

 tional vessels accounted for most of the increase 

 through 1963. In 1964-68, fishing terminated 

 approximately 7 weeks later (mid-November) 

 than in pi-evious years. 



Ill the South Atlantic area, effort fluctuated 

 between 245 and 530 vessel weeks from 1941 

 to 1968. Although some fluctuation was due to 

 variation in the length of the fishing season, par- 

 ticularly in Florida, most was due to variations 

 in the number of vessels. The annual number of 

 vessels, and vessel weeks, generally was less from 

 1960 to 1968 than in previous years. 



In the North Carolina fall fishery, the number 

 of vessel weeks varied from 97 to 457 and 



771 



