3 The David Starr Jordan departed San Diego February 7 to participate in the EASTROPAC Project. The primary objective of the trip was to survey the oceanographic environment of physical and biological rela- tionships between the area of 20°N - 112°W and 20°S - 105°W in an attempt to find a better understanding of pelagic tuna resources. The ship traveled from San Diego to 12°N - 111°W and then headed northeast on a direct line for Manzanilla, Mexico. On 18 February the ship departed Manzanillo and traveled along the coast of Acapulco. From Acapulco, stations were resumed on 20 February and the track ran southwest to 12°N - 105°W. The ship then proceeded south along 105°W to 20°S. From this point a northwestern course was taken without stations until 10°S - 112°W was reached. The Jordan continued along 112°W to 20°N, where the study area ended and then returned to San Diego on 24 March. Environmental data were collected at about 20 mile intervals in all areas between 20°N and 20°S except the two areas previously mentioned. As a visiting scientist aboard the David Starr Jordan, I conducted bird, mammal, and fish observations for 43 days while the ship was at sea. Excellent cooperation was received from Dr. Longhurst, the scientific crew, Captain Foster, and the ship's crew, in all phases of observing and collecting birds throughout the trip. This preliminary report summarizes these observations. In 40 days, a total of 308.5 hours was spent observing, while the ship traveled 3,218 miles. An additional 38 hours of nocturnal obser- vations were recorded from various points throughout the trip. Obser- vations were conducted on three additional days but due to the proximity to the coast only species accounts and relative abundance of species were recorded. During diurnal observations 4,020 birds of 41 species were recorded. Nocturnally, 175 birds of 8 species were recorded. Sooty Terns (1117) were the most abundant. Leach Storm Petrels (948) and Red Phalaropes (137) were regularly seen throughout the trip. Townsend Shearwater (687), Wedge-tailed Shearwaters (291) and Red-footed Boobies (253) were present in large numbers in restricted areas. The most abundant bird throughout the trip in terms of birds per square mile was Leach Storm Petrel. METHODS Observations were conducted from sunrise to sunset throughout most of the trip. Watches were not held during the noon station which varied in length from 2 1/2 to 4 hours. Due to the difference in daily steam- ing time the most important figure is birds per linear mile per day and not total birds per day.