| Title | Processed underway Thermosalinograph (TSG) observations from the Transkei Shelf Oceanography Cruise on the Algoa Voyage 241, July 2017 |
|---|---|
| Project | African Coelacanth Ecosystem Programme (ACEP) |
| Authors |
Leon Jacobs Franklin Frantz Marcel van den Berg Tarron Lamont |
| Publisher | Department of Forestry, Fisheries and the Environment (2023) |
| Contributors |
Contact Person: Leon Jacobs |
| Abstract | Here we present the 6-second resolution processed Thermosalinograph (TSG) data collected between 12 July 2017 and 14 August 2017 during the Transkei Shelf Oceanography Cruise on the RS Algoa Voyage 241. A SeaBird SBE45 TSG is used to opportunistically collect underway near-surface temperature and conductivity measurements during research and monitoring cruises. Water is continuously pumped to the TSG from an intake located in the hull of the vessel, and the observations are continuously interfaced with navigational information. A temperature sensor close to the intake provides temperature measurements of the incoming water (T1). The temperature of the water inside the conductivity cell (T2) is used to accurately compute salinity (S) from the conductivity measurements (C). The area covered by the Transkei Shelf Oceanography Cruise includes the Transkei shelf and continental slope (20m to 1000m), of the Eastern Cape, between Cape St Francis and Port Shepstone in the South-West Indian Ocean. Our knowledge of the distribution of offshore benthic biodiversity on the Transkei shelf is very limited. The region between Algoa Bay and Port Edward is not only important for understanding the functioning of existing Marine Protected Areas (MPAs) such as Pondoland, Dwesa-Cwebe, and the Amathole, but is of particular relevance to the new Operation Phakisa proposed MPA network that will potentially include additional MPAs such as the Protea Banks, Amathole Expansion, and the proposed Addo MPA. |
| Methods | The SeaBird SBE45 Thermosalinograph (TSG) is used on the RS Algoa for the collection of underway near-surface temperature and conductivity measurements. The underway seawater is obtained from a depth of 5m below the surface and pumped through the TSG. Data is collected using the most recent SeaBird (SBE) SeaSave software and processed using the most recent SBE data processing software. The software was set to record data at 6 second intervals for the duration of the cruise, between 12 July 2017 and 14 August 2017. Data was collected in the southern part of the Agulhas Current Large Marine Ecosystem (ACLME) region on the south east coast of South Africa. Unreliable TSG measurements can result from a variety of problems encountered during the cruises, including insufficient water flow, extreme air bubbling during severely adverse weather conditions, debris trapped in the system, or a variety of electronic failures. Detailed visual inspection of the ship trajectory and TSG measurements, as well as comparisons with other concurrent and historical near-surface measurements, and expert knowledge of local conditions, were used to identify and remove all unreliable data. |
| Data | |
| Temporal extent | 12 Jul 2017 – 14 Aug 2017 |
| Geographic extent |
Benguela Current Large Marine Ecosystem (BLMCE), Agulhas Current Large Marine Ecosystem (ACLME)
North: -30.0 |
| Vertical extent |
Max: -5.0 m Min: -5.0 m |
| Keywords | Algoa, Algoa 241, INDIAN OCEAN, SOUTH ATLANTIC OCEAN, THERMOSALINOGRAPH, TSG |
| Related resources |
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