Patterns in acoustically derived biological scatter through the water column were collected with multi-frequency scientific echosounders (Simrad EK80) operating at 18kHz, 38kHz, 70kHz, 120kHz, 18WkHz, and 70WkHz following protocols developed during the NOAA NRDA DAP data collection operations. Specifically, during each cruise, transducers were installed on a rigid pole mounted to the side of the ship, and calibrated at sea for operating conditions following protocols developed by Dr. Boswell during the ONSAP/DAP cruises. The dynamics of the mesopelagic scattering community were examined through the depth dependent scattering responses at both frequencies (18 and 38kHz) as well as through the difference between the mean volume backscattering strength (MVBS; in dB) at 18 kHz and 38 kHz (dMVBS(18-38)). In addition, scatterers in the upper water column (~150m) were examined by analyzing all four available frequencies. By integrating both methods, the magnitude of biological scattering at discrete-depth intervals was classified into major taxonomic components (e.g., fluid-like crustaceans, swimbladdered fishes) based on resonant properties and behavior. The biological data and ship data collected during this cruise are available in GRIIDC datasets R4.x257.226:0001 and R4.x257.226:0003, respectively.
Kevin Boswell. 2016. Raw acoustic scattering data of organisms from the water column, R/V Point Sur, cruise DP01, May 1 - 8, 2015. Distributed by: Gulf of Mexico Research Initiative Information and Data Cooperative (GRIIDC), Harte Research Institute, Texas A&M University–Corpus Christi. doi:10.7266/N76T0K11
To examine the spatial and temporal dynamics of deep sea nekton in the Gulf of Mexico through a multidisciplinary approach.
Data Parameters and Units:
Raw acoustic scattering strength of nekton from water column - scattering intensity (Mean Volume Backscattering Strength, dB), time (hh:mm:ss), Latitude (decimal degrees), Longitude (decimal degrees),depth (m)