Penguin Banks Acoustic Bottomfish Survey (SE0902L2, EK60). Narrow-band, split-beam acoustic data were collected using a Simrad EK60 system operating at 38, 70, and 120 kHz frequencies along predetermined transects to collect reverberation data from organisms in the watercolumn to be processed for echoes of economically important bottomfish.

Penguin Banks Acoustic Bottomfish Survey (SE0703L2, EK60). Narrow-band, split-beam acoustic data were collected using a Simrad EK60 system operating at 38 and 120 kHz frequencies along predetermined transects to collect reverberation data from organisms in the watercolumn to be processed for echoes of economically important bottomfish.

Comparison of fishery-independent methods for sampling Main Hawaiian Islands Bottomfish assemblages (SE1102L1, EK60). Optical, active acoustics, and research fishing data on bottomfish abundance and biomass were collected over predetermined grids to compare results of methodologies. Optical data were collected using a baited stationary Botcam. Acoustics data were collected using a narrow-beam EK60 system operating at 38, 70, and 120 kHz frequencies. Research fishing was conducted using hook-and-line on small boats. Botcam drops with simultaneous acoustic recordings were conducted to obtain target strength measurements of fish with known species and sizes. Bottomfishing off the Sette were conducted simultaneously with acoustics data collection to further groundtruth the acoustics data.

Micronekton sampling gear Intercalibration Experiment Survey #1 (MIE-1) (SE0413L2, EK60). The goal of the cruise was to collect micronekton samples using three different type of midwater trawl: Cobb trawl, Isaacs Kidd Midwater Trawl (IKMT), and a Hokkaido University Frame Trawl (HUFT). Trawls were conducted off the lee coast of the Island of Oahu, Hawaii, in approximately 1,000 m deep waters. Acoustic backscatter was simultaneously monitored during trawls using an EK60 system operating at 38 and 120 kHz frequencies. Trawls sampled the nighttime shallow scattering layer and daytime deep and shallow scattering layers. It total, 18 Cobb, 19 IKMT, and 20 HUFT were completed.

TZCF Oceanographic Survey (SE1102L2, EK60). Data were collected along the 158°W and 161°W Meridionals from 22°30′N-36°00′N and from 31°15′N-35°15′N. CTD cats were conducted at predetermined stations. CTDs were equipped with oxygen sensors and fluorometers, and chlorophyll and nutrients were measured at discrete depths. Biological backscatter and currents were monitored using the EK60 echosounder system (38, 70, and 120 kHz) and an RD Instruments ADCP along the transects.

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.

Comparison of fishery-independent methods for sampling Main Hawaiian Islands Bottomfish assemblages (SE1302, EK60). Optical, active acoustics, and research fishing data on bottomfish abundance and biomass were collected over predetermined grids to compare results of methodologies. Optical data were collected using a baited stationary Botcam, a SeaBED AUV, and a BlueView imaging sonar. Acoustics data were collected using a narrow-beam EK60 system operating at 38, 70, 120, and 200 kHz frequencies. Research fishing was conducted using hook-and-line on small boats. Simultaneous AUV and ROV with active acoustics were operated to obtain target strength measurements of fish with known species and sizes. Bottomfishing off the Sette were conducted simultaneously with acoustics data collection to further groundtruth the acoustics data.

Kona Integrated Ecosystem Assessment Survey (SE1401, EK60). This cruise accomplished the following objectives: Oceanographic data were collected from a total of 6 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. Biological backscatter was monitored using the EK60 echosounder system, both during trawl operations and along 7 acoustic transects (including at least one daytime and one nighttime transit of each transect). One nighttime oblique mid-water trawl was conducted prior to the net being damaged beyond repair by contact with the seafloor. Four casts of a DIDSON imaging sonar were conducted to collect high resolution information on the density of high sonic scattering layers. An ROV was deployed 5 times to investigate acoustic scattering layers and adjacent layers. Deep handline jigging was accomplished during day and night to investigate scattering layer macrofauna. Data on cetacean distribution, school size, and school composition were collected via daytime visual surveys on 9 days of transects coupled with several days of small boat survey effort. Two HARP units were deployed for passive autonomous detection of cetaceans and several sonabuoys were also deployed during daytime operations for cetacean detection and identification.

Cetacean Ecology Survey at North Western Hawaiian Islands (SE1303, EK60). The goal of the cruise was to collect data on the abundance, distribution, stock structure, and habitat of cetaceans in the Papahānaumokuākea Marine National Monument (PMNM) using 7 integrated operations. These operations included visual observations, passive acoustic monitoring, photo-identification, biopsy sampling, satellite tagging, small boat surveys, and oceanography (CTD, Chlorophyll, XBT, and surface samples). A High-frequency Acoustic Recording Package (HARP) was recovered during the cruise.

TZCF Oceanographic Survey (SE1505). Oceanographic data were collected along the 159W and Meridional from 26° 30'N-32° 30'N. CTD casts were conducted at predetermined stations. CTDs were equipped with oxygen sensors and fluorometers, and chlorophyll and nutrients were measured at discrete depths. Biological backscatter was monitored using the multifrequency EK60 echosounder system operating at 38, 70, 120, and 200 kHz.