EK60 Water Column Sonar Data Collected During SE1703

Leeward Oahu Pelagic Ecosystem Characterization (LOPEC-1) (SE1703, EK60). The first primary component of LOPEC-1 on SE1703 was to perform a midwater trawl and bongo net survey from the Oscar Elton Sette to compare to a series of trawl and bongo net surveys from 1951-1978 off leeward Oahu, henceforth referred to as the baseline surveys. The baseline surveys estimated fish composition and abundance for 4 different components of the pelagic community, notably the mesopelagic fish assemblage, shorefish larvae, tuna larvae, as well as a suite of zooplankton taxa from 2 forage availability studies and an early trawl survey. Comparison of current composition and abundances to the baseline composition and abundances after 39-66 years will be a valuable scientific finding to ascertain how the pelagic ecosystem has changed, or not, over that extended time period. The sampling gears used in the baseline surveys from 1951-1978 are 10’ Isaacs-Kidd midwater trawl (IKMT), Cobb trawl, and 70cm bongo nets, all of which are available and deployable on Oscar Elton Sette. The second primary component of LOPEC on SE17-03 was to establish a time series of micronekton and plankton for the leeward Oahu area for ecosystem monitoring. Some operations from the baseline comparison component will be part of the new time series with additional surveys of plankton using other sampling gear such as ring nets and other configurations (different mesh sizes) of bongo nets during both the daytime and the nighttime.