FISHERY BULLETIN: VOL. 87, NO. 3, 1989 



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SEA SURFACE SALINITY (PPT) 



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Figure 8. — Plot of sea surface temperature vs. sea surface salinity for stations on the cruise which had observations of both. 

 Stations with bluefin larvae are plotted as open triangles. The three .\'s show the surface temperature and salinity of the stations 

 near Cape Hatteras where bluefin larvae were collected by Berrien et al. (1978). 



Previous Captures of Bluefin Tuna 

 Larvae off Miami 



Bluefin tuna larvae were collected in 1969-71 

 and in 1975 between Miami and the Bahamas by 

 Richards (1976). On a five-station transect be- 

 tween Miami and Bimini Bahamas (Richards 

 1976, table 2), 82% (32/39) of bluefin tuna larvae 

 taken in neuston tows were taken at two sta- 

 tions. These two stations were located on the 

 Miami side of the center of the Florida Straits 

 where the high velocity core of the current is 

 located on average (e.g., Stommel 1965:139). All 

 of the bluefin tuna larvae taken in bongo tows 

 along the transect were taken at the same two 

 stations where most of the neustonic specimens 

 were collected. All of these larvae were longer 

 than 3.0 mm, older than 3 days, so that, if they 

 were advected at the mean current velocity in 

 this location, 100 km d"' (Fuglister 1951), 

 they would have been spawned west of Key 

 West, FL (long. 82°W). 



In 1981, 369 bluefin tuna larvae were collected 



off Fowey Light, south of Miami, at approxi- 

 mately lat. 25.6°N (Brothers et al. 1983). The 

 collections were made on four days, 19-21 May 

 and 2 June, using 1 m diameter or 1 x 2 m 

 neuston nets which were towed many times each 

 day. No oceanographic data were collected 

 because the purpose of the sampling was to cap- 

 ture specimens for otolith ageing, but the collec- 

 tions were made "5-10 miles offshore in blue 

 water at the edge of the Stream" according to E. 

 D. Prince.' Based on satellite observations dur- 

 ing this period (NOAA Gulf Stream System 

 Flow Chart #2450), the edge of the Gulf Stream 

 was offshore of the 183 m isobath (which is 5-10 

 miles offshore near Fowey Light) on 18 May, 

 was at the 183 m isobath 20 May, and was off- 

 shore again 22 May. Nearly half of the total catch 

 (176/369) of bluefin tuna larvae during four days 

 of sampling took place on 20 May (Brothers et al. 



'E. D. Prince, Southeast Fisheries Center Miami Labora- 

 tory, National Marine Fisheries Service, NOAA, 75 Virginia 

 Beach Drive, Miami, FL 33149, pers. commun. 1988. 



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