EK60 Water Column Sonar Data Collected During OS1209

Island Wake Hotspots. Subsurface features were sampled with multi-frequency acoustics, CTD profiles, pairovet and bongo nets sampling different components of the ichthyoplankton and zooplankton assemblages. Juvenile fishes and squid were sampled with an Isaacs-Kidd mid-water trawl (IKMT). Repeat passes of a glider upstream of the area at Point Conception provided detailed sections of temperature, salinity, fluorescence, velocity and acoustic backscatter. Surface plankton will be sampled with manta nets, the Continuous Underway Fish Egg Sampler, thermo-salinograph, and remote sensing. The wakes are expected to be relatively small, with complex sub-mesoscale structure, and strong temporal variability. The primary species focus of this study was small pelagic fish, rockfishes, and squids. However, the full ichthyoplankton community was counted according to usual protocols, and all species from the IKMT were identified, counted and preserved. Calibrated acoustic backscatter data were interpreted using catches from bongo nets and IKMT and predicted frequency-dependent scattering. CUFES data were enumerated and samples preserved according to normal protocols.