Cruise Report S-207 : Scientific data collected aboard SSV Robert C. Seamans, San Diego, California – La Paz, Baja California Sur – Puerto Vallarta, Mexico. 12 October – 20 November, 2006

Abstract

This cruise report provides a record of data collected during S207 aboard the SSV Robert C. Seamans from San Diego, California to Puerto Vallarta, Mexico (Figure 1) with a stop at La Paz on the southeastern shore of Baja California Sur. We collected samples or data with 170 individual deployments from 91 discrete stations (Table 2) along our cruise track. In addition we continuously sampled water depth, sub-bottom profiles and Acoustic Doppler Current Profiles (ADCP) along with flow-through sea surface temperature, salinity and in vivo fluorescence. This report summarizes physical, chemical and biological characteristics along our cruise track and around surveyed seamounts and islands. The S207 cruise track traversed several oceanic regions that can be distinguished by their sea surface temperature, salinity, density and fluorescence values (Figures 2a-b). Sub-surface water masses and their chemical properties were also surveyed using a CTD and 12 bottle carousel (Tables 4 and 5). Large scale hydrography are summarized by contour plots of temperature, salinity and sound velocity along our cruise track (Figure 3) and for specific transects across key oceanic features (Figures 4a-e) and around surveyed seamounts and islands (Figures 5a-c). Large scale current patterns are summarized by contour plots of current direction, magnitude and echo amplitude (Figure 6). The distribution of neuston net, meter net, and Tucker trawl stations and corresponding zooplankton density and numbers of select nekton species are presented (Tables 6-8). Location and relevant station depths for sediment samples are shown in Table 9. Secchi depth at various locations is also provided (Table 10). A complete oceanographic survey of Jasper seamount, Cerralvo seamount and the coastal waters of Isla Guadalupe were completed. Additional CTD, CHIRP, ADCP and biological data not reported here are available on request through Sea Education Association (SEA) and the Chief Scientist. The information in this report is not intended to represent final interpretation of the data and should not be excerpted or cited without written permission from SEA. In addition, vertical and horizontal distribution patterns of myctophids (lantern fish), and the marine insect Halobates were studied in relation to environmental characteristics. Results, not reported here, are available upon request through SEA. As part of SEA’s educational program, undergraduates conducted independent oceanographic research during the cruise. Project explored regionally, relevant topics in the disciplines of physical, chemical, biological and geological oceanography (Table 11). Student research efforts culminated in a written report and public presentation to the ship’s company. These papers are available on request from SEA.