FISHERY BULLETIN: VOL. 79, NO. 1 



Ocean, and to analyze these data to provide infor- 

 mation on temporal and spatial changes in rela- 

 tive abundance. 



The program is directed primarily at sailfish, 

 white marlin, and blue marlin, although data on 

 recreational catches of yellowfin and bluefin tunas 

 are also recorded. Swordfish and longbill spearfish 

 are rare in the recreational catch, but some data 

 have been obtained. 



Much preliminary work had already been ac- 

 complished in the Gulf of Mexico by the Southeast 

 Fisheries Center Panama City Laboratory, NMFS, 

 NOA A, in cooperation with various big-game fish- 

 ing clubs and charterboat associations along the 

 coast. Sampling sites were established and cover- 

 age of fishing effort during the fishing season in 

 the gulf was estimated to be as high as 90% 

 (Nakamura and Rivas 1974). 



Initial contact with big-game fishing clubs, 

 tournament managers, and others associated with 

 big-game fishing tournaments produced a list of 

 about 40-50 tournaments scheduled throughout 

 the Bahamas, Caribbean, Gulf of Mexico, and 

 along the eastern coast of the United States. Con- 

 tact with various state marine research agencies 

 provided cooperative sampling agreements for 

 tournaments within their states. In addition to 

 tournament sampling, port samplers were 

 stationed in the Gulf of Mexico to maintain day- 

 to-day coverage of nontournament fishing activity 

 at major fishing areas along the coast. At present, 

 coverage includes Port Aransas, Tex.; Grand Isle 

 and South Pass, La.; Orange Beach, Ala.; and Pen- 

 sacola, Destin, and Panama City, Fla. The fishing 

 season in the Gulf of Mexico usually runs from 

 April through October. 



Data Acquisition 



Sampling procedures at tournaments are 

 reasonably uniform regardless of locality or sea- 

 son. At the end of each fishing day, program 

 samplers interview the angler or a member of the 

 crew of each boat participating in the tournament. 

 Information on environmental conditions, 

 number and species offish hooked, and other ac- 

 tivities are recorded. At most tournaments all of 

 the participating boats aire located at a single 

 marina, and sampling coverage is usually 100%. 

 Tournament sampling is further simplified in that 

 most tournaments have rigidly controlled fishing 

 hours, and all boats in the tournament fish the 



same amount of time. After the statistical infor- 

 mation is collected, the sampler obtains biological 

 data from each billfish landed. 



Daily port sampling is more difficult than tour- 

 nament sampling. Fishing frequently takes place 

 from a variety of locations, the boats return to the 

 dock at different times, and fishing effort is fre- 

 quently not as consistent as during tournaments. 

 Much of the success of daily sampling is attribut- 

 able to the samplers' knowledge of the area and 

 their persistence and resourcefulness in obtaining 

 the data. 



Sampling Problems 



There are numerous sampling problems that 

 appear to be unique to the recreational fishery for 

 billfishes. The first is the determination of what 

 constitutes the catch portion of the CPUE ratio. 

 When trolling for billfishes there are three distinct 

 levels of activity that feasibly could be associated 

 with effort and provide an estimate of relative 

 abundance. The first is commonly knov^Ti as a fish 

 "raised." This term refers to the visual observation 

 of a billfish behind the trolling baits whether it 

 ultimately strikes the baits or not. The inherent 

 problem in using this measure is species identifi- 

 cation. In addition, it is apparently not uncommon 

 for a single billfish to be raised more than once 

 during a given day's fishing, occasionally by the 

 same boat. There is also the possibility that two or 

 more billfishes are raised in rapid succession, but 

 the observer may interpret this as a single fish. 

 The second level of activity, and the one used in 

 this study, is fish "hooked." Disadvantages of this 

 criterion are differences in the skills of anglers in 

 hooking fish, and the fewer data obtained since 

 many fish that are raised are not hooked. Its ad- 

 vantages are that identification reliability is con- 

 siderably increased since billfishes almost always 

 jump when hooked and positive identification is 

 usually possible. The third level of activity is a 

 billfish "boated" (or caught and released). The 

 biggest difficulty with this measure of catch is that 

 different tournaments use different categories of 

 line-test; comparing CPUE on 9 kg test line with 

 CPUE on 36 kg test line is not reasonable. Another 

 drawback is that the number of data points avail- 

 able from "boated" fish decreases significantly. The 

 value of this measure is that species identification 

 is no longer a problem. We decided to use fish 

 hooked as our measure of catch, and all sub- 

 sequent references to CPUE in the recreational 



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