EK60 Water Column Sonar Data Collected During MF0706

Oregon - Washington Sardine Survey. Fourteen primary stations were occupied after dusk and prior to sunrise. Daytime activities included occupying a transect between survey lines using the CUFES and the EK-60 sounder. At each night station the following activities were performed: a. Deployment of a Seabird 9/11+ down to 200 meters, bottom depth permitting. The CTD collected depth, temperature, conductivity and chlorophyll fluorescence data. b. A standard Pairovet cast. The Pairovet net was fished from 70 meters to the surface (depth permitting) using paired 25 cm diameter 150 μm mesh nets. The technical requirements for the Pairovet tow was: descent rate of 70 meters per minute, a terminal depth time of 10 seconds and an ascent rate of 70 meters per minute. c. A CalBOBL (CalCOFI Bongo) standard oblique plankton tow with 300 meters of wire out, depth permitting, used paired 505 :m mesh nets with 71 cm diameter openings. The technical requirements for this tow were: Descent rate of 50 meters per minute, ascent rate of 20 meters per minute. All tows with ascending wire angles lower than 38° or higher than 51° in the final 100 meters of wire were repeated. d. Standard meteorological data including SST, wind speed and direction, wave height and direction, cloud cover, relative humidity, air temperature and barometric pressure. e. During all transit between stations continuous measurements were made of pelagic fish eggs (CUFES) and acoustic targets using the EK-60. f. A Nordic 264 mid-water trawl using 3.0 m² foam core doors was towed at the surface for 30 minutes traveling at approximately 3.5 knots. Every catch was sorted and target species were sampled.