EK60 Water Column Sonar Data Collected During MF0804

California Current Ecosystem Survey. 1. Each coast-wide survey station included the following: a. A CTD/Rosette consisting of four 2.5 liter hydrographic bottles lowered to 500 meters (depth permitting) to measure physical parameters and collect water at discrete depths for analysis of salinity. b. A CalBOBL (CalCOFI Bongo) standard oblique plankton tow with 300 meters of wire out, depth permitting, using a 505 µm mesh net paired with a 333 µm mesh net with 71 cm diameter openings. The technical requirements for this tow were: Descent wire rate of 50 meters per minute, held at terminal depth for 30 seconds and retrieved at a wire rate of 20 meters per minute. . A 45° wire angle was closely maintained during the ascent and descent of the net frame. All tows with ascending wire angles lower than 38° or higher than 51° in the final 100 meters of wire were repeated. c. A Manta net (neuston) tow, using a 505 µm mesh net on a frame with a mouth area of 0.133 m². The frame was towed for 15 minutes at a target speed of 60-70 cm/sec or an angle of stray between 20-25 degrees. d. Weather observations. e. A Pairovet (vertical) plankton tow was taken at all stations. 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 Pairovet tows were: Descent rate of 70 meters per minute, held at depth for 10 second duration then an ascent rate of 70 meters per minute. All tows with wire angles exceeding 15° during the ascent were repeated. f. A surface tow using a Nordic 264 pelagic trawl was conducted during nighttime operations. Each tow was fished for a 30 minute duration at a towing speed of approximately 3.5 knots. The catch of each tow was processed in the following manner: Sardines collected in each trawl were randomly sub-sampled. Standard length and body weight were measured, otoliths were collected, and ovaries preserved in buffered formalin. These fish were assigned a maturity code based on a four stage system developed during a previous Tri-national Sardine Forum. 3 g. During daylight hours marine mammal and seabird observations were conducted enumerating and identifying all seabirds and marine mammals encountered. Mammals were not quantitatively surveyed on Leg II. 2. While underway during the coast-wide sardine survey, the following operations were conducted: a. Directed adaptive sampling of pelagic fish eggs using the following protocol: Water was continuously sampled using the CUFES (Continuous Underway Fish Egg Sampler) from a depth of six meters. Approximately 640 liters/minute was sent through a concentrator which filters all material larger than 505 µm. The sieved sample was collected and identified. All fish eggs were identified to lowest taxa, counted and entered into the data acquisition software. Each sample entry is coupled with sea surface temperature, geographical position, wind speed and direction, date and time, and surface salinity. Sampling intervals varied in length, depending on the number of fish eggs seen, from two to sixty minutes with an average interval of thirty two minutes. When two consecutive samples had a concentration of Pacific sardine eggs equal to or greater than 1 egg per minute, the ship stopped to conduct a Pairovet tow. Pairovet tows continued at four mile intervals until a concentration of less than one egg per minute was observed in two consecutive samples. All Pairovet samples were taken concurrently with a CUFES sample in addition to sampling continuously between Pairovet samples. b. Once underway, the Freeman’s Acoustic Doppler Current Profiler (ADCP, RDI 150 kHz model) was sampling at all times. Data was periodically backed up to a writable DVD. c. Once underway, the scientific sounder (Simrad EK-60, 38, 120, and 200 kHz split beam transducer) was sampling at all times. Data was periodically backed up to a writable DVD. d. Once underway, the Freeman’s thermosalinometer (TSG) was run at all times with the ship’s Scientific Computing System (SCS) serving as the main data collection system.