Catch 



First cruise ~ albacore 116 (20 to 35 po\mds)j 



big-eyed tuna 23, striped marlin 7$ 

 sailfish 2, yellowfin tuna 3o 



Second cruise — albacore 285 (30 to 60 pounds), 



black marlin 7, striped marlin 3j 

 yellowfin tuna 6o 



The vertical temperature differential was much g reater than 

 in the winter fishery, being particularly marked on the second 

 cruise (see the following table )o 



Comparative Table of Summer and Ifenter Water Tenperatures 

 on the Albacore Grounds (35°Ns 17U°E) 



During the winter the difference between the surface 

 ten?)eratures and the temperature at 100 meters does not 

 exceed lol° and the difference between the surface and 200 

 meters is not greater than 2o7 c On the first cruise, 

 however, there was a difference of 3° between the surface 

 temperature and the temperature at 100 meters, and a differ- 

 ence of iio 3° between the surface and 200 meterSo On the 

 second cruise, there was already a difference of 7o2° at 50 

 meters, 8o2° at 100 meters, and 11 at 200 meters. Such a 

 great vertical differential in water temperature is generally 

 regarded as unfavorable for tuna longline fishingo (in the 

 course of this same survey, where good fishing was found on 

 the first cruise the difference between water temperatures 

 at the surface and at 100 meters was 3°, and the difference 

 between the surface and 200 meters was U"U°o IShere no fish 

 at all were caught, there was a difference of k° between the 

 surface and 100 meters, and 6o5° between the surface and 



