the Gulf of Tehuantepec on the Pacific coast of 

 southern Mexico (adjacent to Guatemala). In- 

 terest in this area was aroused as a result 

 of a few observations made on Expedition 

 EASTROPIC in December 1955 (Brandhorst, 

 1958), and a much larger survey was made 

 by STOR investigators in May and June 1958 

 during SCOT Expedition (Holmes and Black- 

 burn, 1960). It was then decided to make three 

 more surveys at different seasons of the year, 

 which was done with the results summarized 

 in this report; analysis of the results of all 

 four surveys is now proceeding. 



The three cruises are known as TO-58-2, 

 TO-59-1, and TO-59-2. Figures 1 to 3 

 show the cruise tracks and observation posi- 

 tions. 



TO-58-2 began at San Diego, California, on 

 October 31, 1958, and ended there on Decem- 

 ber 8, 1958. The ship was the Spencer F. Baird, 

 and the cruise leader was Dr. Gordon W. 

 Groves. 



TO-59-1 began at San Diego on January 15, 

 1959, and ended there on February 25, 1959. 

 The ship was the Stranger, and the cruise 

 leader was Mr. Robert W. Holmes. 



TO-59-2 began at San Diego on August 13, 

 1959, and ended there on September 22, 1959. 

 The ship was the Hugh M. Smith, and the cruise 

 leader was Dr. Maurice Blackburn. 



As figures 1 to 3 show, each cruise was 

 used to make observations in other tuna 



Figure l.--Track chart of cruise TO-58-2. 

 2 



