SCIENCE AND THE SEA 



After the liner has set all her gear, she returns to the starting 

 point and commences to work her way back along the rig. The main 

 line is hauled aboard by a power-driven line-hauler. Once aboard, 

 catch is removed, hooks rebaited, and gear reset. 



Subsurface long-lining has proved highly successful for harvesting 

 albacore, yellowfin, bluefin, and bigeye tuna. Identification of this 

 gear is very simple due to the long string of glass floats on the surface, 

 and the flagged markers. 



Bottom long-line operating procedures are quite similar to those 

 of subsurface lining. Instead, however, of suspending the main line, 

 it is anchored to the bottom. Flagged bamboo pole markers are again 

 used to mark the course and also the anchor sites. Glass floats are not 

 required. Line hauling and baiting routines are carried out in the same 

 fashion described for subsurface rigs. Bottom lining is the principal 

 harvesting method used by the large halibut fishery off the United 

 States Pacific coast. Figure 6 depicts a typical subsurface and bottom 

 long-line rig. 





|t^ 







A Subsurface long line ng B Bottom long hne r 



Figure 6 



DRIFTERS 



Drifters, once the very heart of the British, Scandanavian and 

 European pelagic fishing industry, have steadily declined in number 

 over the past 20 years. Norwegian fishermen, for example, are sub- 

 stituting purse seines for drift nets with excellent results. In fact, 

 Norwegian purse seiners harvested 400,000 tons of fish during 1964 in 

 the North Sea alone. This was about one-half the total catch. Many 

 British drifters have been converted to near-water trawlers, and now 

 engage in demersal or pelagic fishing, depending on season and 

 abundance of fish. Regardless, however, of their diminishing strength, 

 drifters still contribute substantially to the total annual catch. 



Drifters usually operate in fleets within 10 to 60 miles of their 

 base port. Throughout the season, base ports must be shifted as fish 

 migrations dictate but are always adjacent to the grounds being 

 worked. Actual fishing operations are conducted only between dusk 

 and dawn. During this period, a concentration of drifters present a 

 formidable navigational hazard to any vessel wishing to transit the 

 area. Radio navigational warnings are occasionally broadcast when 

 concentrations of drifters are unusually large. If possible, the prudent 

 watch officer should alter his course and go around the fleet. Timely 

 action will not only prevent possible loss of an expensive net, but will 

 save incalculable strain on the nervous systems of all concerned. 



North Sea vessels average between 60 and 100 feet in length and 

 are either steam or diesel-powered. Designed to bring in fresh fish, 

 they operate on short trips and have limited accommodations for crew 

 or provisions. Once nets are out, a small triangular or gaff-rigged 

 mizzen sail is set to increase stability and keep vessel's head into the 

 wind. A pivoted derrick boom and large capstan are located well 

 forward for handling the catch. To reduce rolling, this pivoted boom 

 is normally lowered and cradled on the wheelhouse roof when not in 

 service. 



Photo — Hi:rd and Mscken/ie Lim^md 

 Atlantic long liner 



Pacific halibut long liner 



36 



