Earle (1940) and de Sylva and Davis (1963) pre- 

 sented data on sizes of white marlin from the Mid- 

 dle Atlantic Bight, from Long Island, New York, to 

 Hatteras. North Carolina, while Erdman (1962, 

 1968) and de Sylva (1963) reported on sizes of blue 

 marlin taken at Puerto Rico and Jamaica, respec- 

 tively. Williams (1970) presented extensive length 

 and weight data on sailfish taken from off Kenya, 

 East Africa. Size distribution of sailfish, as re- 

 flected in taxidermists' records, from the south- 

 eastern United States, were reported by de Sylva 

 (1957). To this writer's knowledge, these represent 

 the sum total of published size data on the sport 

 fishery for billfishes. A detailed analysis of the 

 size-frequency distribution of billfish in the sport 

 catch in the western hemisphere is presently being 

 carried out by the writer, but, except for a few 

 specific areas (Maryland, North Carolina, south 

 Florida, Jamaica, Puerto Rico, the northern Gulf 

 of Mexico), few good data are available. There- 

 fore, a request is made herein to any anglers or 

 angling clubs in the western hemisphere who have 

 records of the size of billfish they have caught, or 

 catch per effort data, to submit them for analysis. 



TIME OF BILLFISH ANGLING 



Swordfish feed more frequently at night, as indi- 

 cated by longline catches, although they are taken 

 by anglers during the day. Possibly the difficulty 

 which anglers experience in getting a swordfish to 

 take a bait is associated with its poor daytime visi- 

 bility, or because it also feeds by smell. 



The istiophorid fishes feed largely by sight. 

 Longline catches, and the condition of the stomach 

 contents of billfishes, indicate that they feed at 

 dawn and dusk, when they probably rise closer to 

 the surface, descending to deeper levels during 

 daylight hours, possibly just above the thermo- 

 cline. 



The angling effort for istiophorids is conducted 

 almost exclusively from 8, 9, or 10 a.m. until 4, 5, 

 or, at the latest, 6 p.m. Hence, most angling for 

 billfish is done not only when they are not actively 

 feeding, but also when they are swimming at sub- 

 surface depths. That small fraction of the billfish 

 population which does rise to the bait trolled dur- 

 ing daylight hours may be hitting the bait out of 

 curiosity, as evidenced by the occasionally very 

 full stomachs of billfish taken by anglers. In short, 

 billfish anglers usually fish at the wrong time. 

 Sport fishing for billfish is often merely a part of 



the overall relaxation pattern for an angler, and he 

 usually fishes during the day and returns relatively 

 early, usually well before dusk, for relaxation back 

 at port. Hence, even though the captain may feel 

 that he should fish later, the angler may suggest 

 that fishing cease earlier. Of course the frequently 

 long runs to and from the fishing grounds and the 

 sometimes tortuous navigation path back home 

 may not permit the captain to fish late. Those cap- 

 tains who make runs to the fishing grounds and 

 overnight on them, so that they can fish earlier or 

 later than usual, frequently make good catches. 



Few data are available from anglers" or captains" 

 logbooks on the best time of fishing. However, 

 data from the Bahamas and Jamaica suggest that 

 from 6 to 9 a.m. and from 3 to 6 p.m. are the best 

 for getting strikes (de Sylva, 1974). It is not known 

 if billfish will take a trolled bait between 6 p.m. 

 and 6 a.m. because little, if any, angling is con- 

 ducted during this period. 



SPECIAL PROBLEMS OF THE 

 BILLFISH SPORT FISHERY 



Sport fishing activities for billfish in the past 

 have not been well documented. There is a press- 

 ing need for qualitative and, especially, quantita- 

 tive information if this valuable fishery is to be 

 managed, and if the potential sociological conflict 

 between sport and commercial fishermen is to be 

 resolved. Now that we are faced with growing en- 

 vironmental problems, such as the deleterious ef- 

 fects of polluted water on sailfish or the high con- 

 centrations of heavy metals in swordfish, we must 

 pay more attention to the dynamics of the marine 

 environment. These much-needed data can only be 

 obtained through the cooperation of the angler, 

 commercial fisherman, boat captain, the sport and 

 commercial fishing industry, and the scientist. Let 

 us consider, therefore, the components of the sport 

 fishery which are so peculiar to billfish. 



The Fishing Grouncis 



Sportfishing grounds for billfish are greatly in 

 need of having their ecological characteristics de- 

 fined. There is a serious lack of information on the 

 physical and chemical characteristics of the angling 

 grounds, including the distribution of temperature, 

 salinity, oxygen, and turbidity, and their interaction 

 with plankton, micronekton, and billfish. How 

 these factors interrelate with one another may af- 



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