EK60 Water Column Sonar Data Collected During SE1304

Kona Integrated Ecosystem Assessment Survey (SE1304, EK60). This cruise accomplished the following objectives: Oceanographic data were collected from a total of 21 CTD casts and continuous TSG measurements along a predefined grid off the west coast of Hawaii to assess the influence of physical dynamics on the region's biological productivity. CTD-mounted fluorometer measurements were carried out by two fluorometers. Chlorophyll was measured for ten discrete samples per CTD using a bench top Turner 10-AU fluorometer. Water samples were preserved for post-cruise flow cytometry to determine phytoplankton size structure. Biological backscatter was monitored using the EK60 echosounder system, both during trawl operations and along 71 acoustic transects at 38, 70, and 120 kHz frequencies. Twenty two nighttime oblique mid-water trawls were conducted targeting the shallow sound scattering layer. Visual surveys for a total of 70 hours were conducted to collect data on cetaceans. A Seaglider was successfully deployed to collect temperature, salinity, and fluorometry data.