• RELEASE 



O RECAPTURE 



LESS THAN 1 YEAR 

 MORE THAN 1 YEAR 



100° 



Figure 4. — Locations of releases and recaptures of white marlin tagged in the western 

 North Atlantic Ocean south of lat. 33°N. The months and years of release and recapture 

 are shown in that order for each return. 



both concluded that the white marlin of the North 

 Atlantic and those of the South Atlantic constituted 

 separate spawning populations. 



The migration from off southeastern Florida in 

 November to north of Jamaica in April likewise 

 bears no apparent relationship to our other results. 

 Much more tagging in southern waters is needed to 

 solve the complex problems of stock identification 

 and migratory patterns of the white marlin which 

 occur there. 



Growth and Life Span 



Reliable growth data cannot be obtained from our 

 tagging results since the sizes of fish when released 

 are estimated, and it is even difficult to assess tne 

 quality of the size data accompanying returned tags. 

 Nevertheless, some general conclusions may be 

 drawn. White marlin usually recruit to the fishery, 

 at least in the Maryland-New Jersey area where 

 most of the tagging was done, at sizes of about 15 kg 

 (de Sylva and Davis, 1963). It can thus be assumed 

 that most of the white marlin tagged were of this 

 size, or larger. Eleven tagged white marlin have 

 been recaptured after periods of 3-6 yr at liberty, 



and none of their reported weights at recapture ex- 

 ceeded 30 kg. The maximum weight recorded for 

 white marlin is 73 kg (International Game Fish As- 

 sociation, 1972). It thus appears that white marlin 

 do not grow very rapidly after recruitment into the 

 sport fishery. 



Despite the increased volume of returns, which 

 perhaps indicates increased fishing pressure, times 

 at liberty have continued to be very long (Table 3). 

 Eleven of the new returns were from fish which had 

 been at liberty for more than 30 mo. The times at 

 liberty for two of these, 55.2 and 58.7 mo, are the 

 longest of which we have positive knowledge for 

 any tagged istiophorid fish. A much greater time at 

 liberty, nowever, may have been enjoyed by a 

 white marlin which was recaptured off Montauk, 

 Long Island, New York, in July 1959. A red plastic 

 ring which was found on the bill of this fish was 

 returned to us. We recently found reference to the 

 use of such rings to mark white marlin at Ocean 

 City, Maryland, in 1939 (Earle, 1940). We checked 

 with various captains who were involved in this 

 program and Captain Louis S. Parsons reported 

 that he had used some of these rings in the seasons 

 of 1947 and 1948. Unfortunately, the ring carried no 



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