NICHOLSON: ATLANTIC MENHADEN TURSE-SEINE FISHERY 



in fishing methods after World War II (Robas, 

 1959). Pumping fish directly from the purse 

 seine to the hold replaced the time-consuming 

 method of brailing and left more time for scout- 

 ing and making additional sets. By 1955 nearly 

 all vessels were equipped with fish pumps 

 (Table 2). 



Before fish in the seine can be pumped or 

 brailed aboard the carrier vessel, they must be 

 concentrated, or "hardened-up." This can be 

 done by crewmen in the purse boats pulling in 

 the net by hand, but it is a laborious process that 

 requires approximately 22 men. A mechanical 



Table 2. — Percent of vessels equipped with fish pumps 

 and power blocks in the Atlantic menhaden purse-seine 

 fi.shorv. 



a Includes Amogansett from North Atlantic Area, 



device, or "power block," for "drying-up" the net, 

 used experimentally in 1955, became operational 

 in 1956 (Schmidt, 1959a). Its use reduced the 

 crew by 6 to 10 men and the average time to 

 "harden-up" the fish by about 6 min (Schmidt, 

 1959a, 1959b), and enabled the crew to retrieve 

 the net quickly if the fish were missed. Power- 

 blocks were used extensively for the first time 

 in 1958 and by 1966 were installed on nearly all 

 vessels from Long Island southward (Table 2). 



Large sets are sometimes lost when the net 

 cannot be raised manually or mechanically to 

 concentrate the fish so that they may be pumped. 

 But the pump head, if positively charged with 

 electricity, becomes an electrode that attracts and 

 concentrates menhaden without the necessity of 

 raising the bunt (Kreutzer 1959). Such a de- 

 vice, commonly called a "fish shocker," was first 

 installed on vessels in 1956, but its use did not 

 spread beyond the Middle and North Atlantic 

 areas. By 1966 it had fallen into disuse 

 (Table 3). 



Beginning in 1954, nylon nets gradually re- 

 placed cotton or linen nets (Table 3) . Although 

 moi-e expensive initially, nylon nets last longer 

 and do not split or tear when filled with fish 

 as other nets sometimes do. 



Aluminum purse boats began replacing wood- 

 en purse boats in 1957 (Table 3) . Being lighter, 

 more maneuverable, and more stable than wood- 

 en boats, they can encircle a school of fish easier 



Table 3. — Percent of vessels equipped with fish shockers, nylon nets, and aluminum purse boats in the Atlantic 



menhaden purse-seine fishery. 



a Includes Amogansett from North Atlantic Area. 



767 



