The SE1302 project aboard the NOAA research vessel Oscar Elton Sette was recently completed after 15 days of work off the western coast of Maui (15-29 April, 2013). This project was the latest in the series of deepwater bottomfish calibration (also termed methods comparison) research projects, and had several objectives: 1) orchestrate a multi-vessel, multi-gear intensive survey of deepwater bottomfish using Sette-based active acoustics (Simrad EK60 operating at 4 frequencies), Sette-based AUV (SeaBED with stereo-camera optics and BlueView sonar imaging), partner vessel BotCam deployments (Huki Pono from Sea Engineering chartered by UH Oceanography), and partner vessel bottomfishing (PIFG charter vessels Hokuloa, Imua, and Naomi K); 2) evaluate alternate acoustic calibration methodologies (shallow-water mooring buoy, single-point anchored, and drifting in deep water); 3) evaluate the use of the over-the-side-pole (OTSP) for acoustic surveys to minimize bubble interference as observed using the hull mounted transducers; and 4) ground truth acoustic targets using Sette-based ROV and fishing operations conducted simultaneous with active acoustics. Most of the objectives were accomplished in a small series of 6 pairs of survey grids located off West Maui (6 survey locations denoted A-F below, with pairs 1, 2 for each A-F). These locations were chosen based on feedback from the local fishing community, prior calibration cruise surveys, climatological patterns of weather, and proximity to small vessel port (Maalaea Harbor).
The research project was fully successful on all 4 objectives despite occasional challenges such as AUV mechanical issues and placement of and locating suspended acoustic calibration sphere. Notably, SE1302 was the first calibration cruise to successfully deploy all 4 survey gears (active acoustics, AUV, BotCam, and fishing) on a single trip. The project also made significant breakthroughs in understanding the acoustic calibration process from the Sette and identifications of potential improvements. The OTSP has great promise for improving acoustic surveys in a wider variety of sea conditions. And lastly during the project there were observations of at least 2 species of fish (opelu and opakapaka) with the navigational camera aboard the ROV, and Sette-based fishing operations captured at least 6 species of fish (opelu, opakapaka, kalekale, ehu, taape, reef shark), while at the same time using active acoustics on the Sette. These ground-truthing data points will be extremely valuable towards helping decipher species identification from the sometimes nebulous acoustic data.
The SE1302 project was a very large collaborative effort between multiple research groups at PIFSC (Ecosystems and Oceanography Division, Fisheries Research and Monitoring Division, Coral Reef Ecosystem Division, Directors Office Scientific Operations, and Operations, Management and Information Division), as well as partners from the Northwest Fisheries Science Center, University of Hawaii Department of Oceanography, Hawaii Institute of Marine Biology, University of Hawaii Joint Institute for Marine and Atmospheric Research, Pacific Islands Fisheries Group, Sea Engineering, State of Hawaii Department of Land and Natural Resources, and NOAA Teacher-at-Sea Program. Colleagues from the University of Miami and Woods Hole Oceanographic Institute were also involved in the planning and preparation for SE1302.