Abstract:
A Slocum glider was deployed in the eastern Gulf of Mexico off Tampa Bay in July and August 2016. As the glider traversed its transit path, measurements were collected at various depths from ~2 m to near the seafloor or up to 200 m. While the glider was deployed at sea, it surfaced and communicated to an onshore control station at predetermined intervals. A decimated selection of vehicle and science measurement was transmitted during the surface transmissions, and the relevant data became available through a USF web site. After the glider’s recovery at the end of the deployment, the complete measurement suite was downloaded from the vehicle, processed and becomes available through the USF site including a national data archive. The measurements in this data set included water column biomass estimates and the raw echosounder water column backscatter intensity measurements. Other data sets for this deployment included environmental water quality parameters and acoustic tag telemetry detections.
The glider was deployed on 2016-07-29 at the 30 m isobath. It traversed for a week to the northwest before turning around and returning along a similar route to the southeast. It was recovered on 2016-08-12 near the deployment site. The intent was for the glider to follow the progression of the Gulfstream Natural Gas Pipeline, collecting water quality and acoustic data sets.
The suite of related datasets includes results from gliders M66, M69, M70, and M72.
Glider M66: water quality variables (FL.x707.000:0001, https://doi.org/10.7266/N72N50PF), tag telemetry (FL.x707.000:0002, https://doi.org/10.7266/n7-ccc2-s109), and echosounder backscatter intensity (FL.x707.000:0003, https://doi.org/10.7266/n7-9yq5-w169).
Glider M69: water quality variables (FL.x707.000:0004, https://doi.org/10.7266/n7-n30g-bw27); acoustic tag telemetry receiver detections (FL.x707.000:0005, https://doi.org/10.7266/n7-406m-ak69), echo sounder backscatter (FL.x707.000:0007, https://doi.org/10.7266/n7-4skm-bj34), and passive acoustic recordings (FL.x707.000:0006, https://doi.org/10.7266/n7-5y6c-sj73).
Glider M70: water quality variables (FL.x707.000:0010, https://doi.org/10.7266/g51f95wz), and tag telemetry (FL.x707.000:0008, https://doi.org/10.7266/p2ymsrp4).
Glider M72: water quality variables (FL.x707.000:0011, https://doi.org/10.7266/ehj8evgw), and tag telemetry (FL.x707.000:0009, https://doi.org/10.7266/9va17amx).
Suggested Citation:
Lembke, Chad, David Mann, Susan Lowerre-Barbieri, Chris Taylor, and Steven Murawski. 2025. Eastern Gulf of Mexico glider deployment M66 (2016-07-29 – 2016-08-12) – echosounder water column backscatter intensity. Distributed by: GRIIDC, Harte Research Institute, Texas A&M University–Corpus Christi. doi:10.7266/n7-9yq5-w169
Purpose:
Demonstration of fisheries-applicable datasets obtained by underwater gliders, including tag telemetry receivers, passive acoustic recordings, and echosounder derived water column acoustic backscatter.
Data Parameters and Units:
NASC [m^2/nmi^2], depth [m], date [YYYYMMDD], time [HH:MM:SS.SSSS], latitude [decimal degrees N], longitude [decimal degrees E], backscatter.
Methods:
Based on echosounder results, water column biomass was calculated based the Nautical Area Scattering Coefficient (NASC). The NASC calculation is the sum of all backscatter in an ensonified volume (in this case, the water column under the glider, excluding the seabed, along a 100 m length of travel), translated to the surface area sampled (2D). The Nautical Area converts to units of scattering per square nautical mile (instead of per square meter).
Provenance and Historical References:
Lembke, Chad; Lowerre-Barbieri, Susan; Mann, David; Taylor, J. Christopher (2018). Using three acoustic technologies on underwater gliders to survey fish. Marine Technology Society Journal 52(6), 39-52. DOI: https://doi.org/10.4031/MTSJ.52.6.1
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