CHANGES IN CATCH AND EFFORT IN THE ATLANTIC MENHADEN 



PURSE-SEINE FISHERY 1940-68 



William R. Nicholson' 



ABSTRACT 



The catch, number of vessel weeks, and catch per vessel week in the Atlantic menhaden fishery increased 

 during the 1950's. During this period fishing methods improved and the efficiency of vessels increased. 

 Improvements included use of airplanes for spotting schools, aluminum purse boats, nylon nets, power 

 blocks, and fish pumps for catching and handling fish, and larger and faster carrier vessels that could 

 range farther from port. The catch and catch per vessel week began declining north of Chesapeake Bay 

 in the early 1960's. By 1966, fish north of Chesapeake Bay had become so scarce that plants either 

 closed or operated far below their capacity. In Chesapeake Bay the number of vessel weeks increased, 

 and the catch and catch per vessel week decreased through the early and mid 1960's. Variations in 

 catch, effort, and catch per unit of effort showed no trends in the South Atlantic. The annual mean 

 number of purse-seine sets per day varied in different areas and ranged from about 2.0 to 4.5. The 

 annual mean catch per set ranged from about 11 to 25 metric tons. 



Catch and effort statistics are important in eval- 

 uating and managing any fishery. They may be 

 used in measuring changes in actual or apparent 

 abundance, estimating population sizes and mor- 

 tality rates, and determining optimum fishing 

 rates. 



When investigations of the Atlantic menhaden 

 (Brevoortia tyrannus) fishery were begun in 

 1955 by the Bureau of Commercial Fisheries, 

 provisions were made for collecting and com- 

 piling catch and effort statistics. The number 

 and locations of daily purse-seine sets were ob- 

 tained from logbooks placed aboard vessels at 

 the beginning of the fishing season, and daily 

 catches of individual vessels were copied from 

 plant records. 



The objectives of the present study were: 

 (1) to analyze logbook data and vessel landing 

 records to determine differences and changes in 

 the number of purse-seine sets, mean number 

 of sets per day, and the mean catch per set, both 

 between and within geographical divisions of the 

 fishery, (2) to develop a method of measuring 

 fishing effort, and (3) to document changes that 

 have occurred in the fishery. 



' National Marine Fisheries Service, Center for Est- 

 uarine and Menhaden Research, Beaufort, N.C. 28516. 



Manuscript accepted April 1971. 



FISHERY BULLETIN: VOL. 69. NO. 4, 1971. 



BRIEF HISTORY OF THE FISHERY 



Atlantic menhaden are found from central 

 Florida to Nova Scotia and at one time or an- 

 other have been exploited over most of this 

 range. Fishing began in the early part of the 

 19th century in waters off Massachusetts and 

 Maine. Following improved methods of fishing, 

 extracting oil, and processing meal, the fishery 

 expanded in this area in the latter part of the 

 19th century. When the scarcity of menhaden 

 in waters north of Cape Cod caused the collapse 

 of the fishery in that area, about 1895, the in- 

 dustry shifted to the Middle and South Atlantic 

 coast. By the 1930's processing plants were lo- 

 cated in approximately the same areas where 

 they occur today (Figure 1). 



Although in some areas pound nets capture 

 menhaden incidentally with other species, purse 

 seines catch nearly all of the fish that are reduced 

 for meal and oil. 



Purse seining began in the late 19th century 

 and by present standards was inefficient and la- 

 borious. Purse boats were rowed and carrier 

 vessels were sailed. Gradually, sailing vessels 

 were replaced by larger, coal burning steam 

 ships, purse boats were equipped with gasoline 



765 



