Rybovich (personal communication), upon examin- 

 ing slides of this fish, indicated that Cuban and Ven- 

 ezuelan commercial fishermen have long been famil- 

 iar with this form which they called "hatchet mar- 

 lin'" or "axe marlin," in allusion to the truncated 

 dorsal lobe. This form (or species?) could enter the 

 sport fishery in some locations; its taxonomic rela- 

 tionships are presently under study by the author 

 and Dr. C. Richard Robins. 



DISTRIBUTION OF SPORT 

 FISHING EFFORT FOR BILLFISH 



Billfishes are found throughout the tropical and 

 temperate seas of the world. With the advent of 

 organized commercial fisheries for tuna and bill- 

 fishes, a mass of data has accumulated on the dis- 

 tribution of billfishes throughout the world's oceans 

 based largely on longline catches (see for example 

 Howard and Ueyanagi, 1965, and references 

 therein; Fox. 1971; Howard and Starck. 1974; 

 Nankai Regional Fisheries Research Laboratory, 

 1954; 1959; Ueyanagi et al.. 1970). Longline catches 

 give some indications of the depth where billfish 

 actually occur because baits are distributed, from 

 many miles of floating line, from the surface to a 

 depth of over 150 m. Billfishes are thus caught using 

 dead baits drifted at various deeper levels, where 

 billfishes apparently spend most of their time. Bill- 

 fishes may be taken in the upper levels during set- 

 ting and retrieving of the longline, when the baits 

 are moving through the water (Fox, 1971). In con- 

 trast, the sport fishery techniques used for billfishes 

 (which are described subsequently) generally in- 

 volve a bait which is trolled at the surface, which is 

 not believed to be a normal part of the billfish envi- 

 ronment. Thus, for a trolled bait to be seen by a 

 billfish, water transparency must be good and sea 

 conditions such that the bait is visible to the billfish. 

 Considering the small size of the bait and the depth 

 at which billfish normally swim, it is indeed surpris- 

 ing that anglers catch as many fish as they do. We 

 might say that the angler trolling a mullet at the 

 surface will catch only a fraction of the billfish 

 which swim 100 m beneath his boat. 



Thus, while from the biological standpoint the 

 distributional charts based on longline catches show- 

 ing when and where marlin occur are valuable to the 

 prospective longliners, they are of less value to the 

 angler because he is not fishing at the depths where 

 the marlin may be actually commonest and, theoret- 



ically, he might troll for months without ever raising 

 a marlin from the depths. Nevertheless, the angler 

 will certainly have a much better statistical chance of 

 success if he fishes when and where billfish are 

 known to occur in commercial catches. In the sub- 

 sequent section, therefore, reference is made fre- 

 quently, where appropriate, to geographic areas 

 which are potentially important sport fishing centers 

 for the various species, as well as to those which are 

 already known to be good for billfishing. 



Billfish Species and their 

 Distribution 



Sailfish are found throughout tropical seas, usu- 

 ally close to large land masses. In comparison to 

 other billfishes. sailfish are found less about islands 

 and tend to come closerto shore into "green water." 

 in contrast to the "blue-water" nature of the other 

 billfishes. possibly merely because of their relative 

 abundance. Sailfish are not especially migratory, al- 

 though some tagged individuals have traversed great 

 distances. They reach a weight of over 100 kg, and 

 are highly prized by anglers. The juveniles, espe- 

 cially, make handsome mounted specimens. A popu- 

 lar account on sailfishing is presented by Tinsley 

 (1964). 



White marlin are found only in the Atlantic. Al- 

 though they form dense, seasonal aggregations in 

 coastal waters, whites occur far offshore prior to the 

 spawning season. They tend to migrate consider- 

 ably, and probably consist of two or more popula- 

 tions. White marlin occur frequently in blue water, 

 although one of the largest concentrations available 

 to anglers is in the green, phytoplankton-rich coastal 

 waters of Venezuela. This species, which reaches a 

 weight of about 73 kg, is a spectacularjumper whose 

 acrobatics are perhaps comparable only to those of 

 the related striped marlin. 



Blue marlin are confined to the tropics of the world 

 oceans, and apparently do not migrate widely. In the 

 northern hemisphere of the Atlantic and Pacific 

 Oceans they seem to move in a southeast to north- 

 west direction between May and September and 

 conversely from northwest to southeast from 

 November to March. Blues are common near large 

 islands and in the open sea, preferring clear blue 

 water. The International Game Fish Association 

 (IGFA) presently recognizes, for angling purposes, 

 the Atlantic blue marlin and the Pacific blue marlin, 

 though taxonomic differences may not exist. In the 

 Atlantic, the blue marlin reaches nearly 550 kg. 



15 



