48 FISHES AND FISHERY METHODS 



In some traps several outer heart-shaped chambers are made. At times 

 the outer hearts are referred to as ''jiggers." 



Hook and Line Techniques 



Hook and line methods are used throughout the world. The objective 

 of modern hook and line fishing is to orient fishing lines in such a man- 

 ner as to obtain maximum geographic coverage by the hooks while at 

 the same time minimizing the amount of effort required to handle the 

 paraphernalia. 



Hook and line fishing can be divided into four categories: (1) hand 

 lines, (2) pole and lines, (3) troll-line fishing, and (4) long lines or set 

 lines. In hand-line fishing the gear consists of a single line, sinker, and 

 perhaps several hooks. In the United States this type of fishing is prac- 

 ticed commerically only in the Gulf of Mexico snapper fishery and in 

 some of the smaller inshore fisheries. 



The use of the pole and line in major commercial fisheries is most 

 prominent in the exploiting of tuna and mackerel-like fishes. Basic gear 

 for pole and line fishing of tuna consists of short bamboo poles ranging 

 from 7 to 17 feet in length and fishing lines composed of several sections. 

 In the California tuna fishery, the ends of the poles are laced with a linen 

 or nylon loop to which a 2)^- to 4-foot length of heavy cotton line is 

 attached. From the cotton line a wire leader made up in two sections is 

 added, with a barbless hook or feathered jig attached to the end of the 

 leader. At times when extremely large fish are encountered two poles 

 are joined to a single leader and one fish hauled from two poles. The 

 length of the poles and leaders is determined by the size and behavior of 

 the fish. In the United States yellowfin, skipjack, and albacore tuna are 

 the principal species harvested by this method. 



Troll fishing adds motion to the bait or lure being used. Simple trolling 

 may be conducted by one line. However, in modern trolling, such as in 

 the Pacific salmon fisheries, as many lines as possible are used. To achieve 

 spatial distribution of the lines, outriggers or spreader poles are used. 

 The fishing lines are attached to tag lines which are tied to the trolling 

 poles. At the end of the trolling line heavy ''cannon ball" weights are 

 placed which may weigh from 18 to 50 pounds. Four or five lures or 

 baited hooks, spaced approximately 6 feet apart, are fished from the end 

 of the main line to which the cannon ball weight is attached. The number 

 of lines which may be fished from a trolling vessel is, in some areas, 

 governed by conservation laws. During fishing, the vessel moves forward 

 slowly (the speed dependent on the fish sought) giving action to the lures. 



In the more advanced line fisheries, long lines are used. The general 

 design of the longline is rather simple, being constructed of a main line 



