| Title | Pre-processed SADCP data from the South Coast Moorings and Monitoring Lines Cruise on the Algoa Voyage 213, December 2014 |
|---|---|
| Project | South Coast Moorings and Monitoring Lines Cruise |
| Authors |
Oceans and Coastal Research |
| Publisher | Department of Forestry, Fisheries and the Environment (2017) |
| Contributors |
Contact Person: Marcel van den Berg |
| Abstract | This is pre-processed Shipboard Acoustic Doppler Current Profiler (SADCP) data from the South Coast Moorings and Monitoring Lines Cruise on Algoa Voyage 213 on 1 to 19 December, 2014. Between 1988 and 2011, environmental and plankton sampling was conducted every summer along the South Coast during the annual pelagic spawner biomass surveys. Data collected during these cruises has provided valuable insight into environmental change in this region. There has been significant decline in copepod biomass on both the western and central Agulhas Bank over the past two decades, as well as a decline in the proportion of the large dominant species Calanus agulhensis, resulting in a shift towards a smaller copepod-dominated community. These changes are thought to have been largely driven by predation by planktivorous fish, which have increased in biomass since the mid-1990s, but increasing sea temperatures have also played a role. It is vital that we continue to monitor the environment and plankton community in key areas off the South Coast to extend our time-monitor series of data and to gain further insight into the possible effects of climate change and variability on this important Agulhas Bank shelf system, which straddles both the Benguela Current and Agulhas Current Large Marine Ecosystems. Monitoring lines off Walker Bay, Mossel Bay and Port Alfred have been selected to represent the western, central and eastern Agulhas Bank respectively. Monitoring in these areas will detect variability in important oceanographic features, such as the cold ridge and divergent upwelling, and will also span key spawning areas of pelagic fish. The Algoa Bay and Port St John monitoring line has been added to the south coast mooring cruises during 2013 and these long term lines will be completed to add to the above mentioned lines. This dataset was processed using older standards which may not align with international best practices and the standards currently adhered to by the Department of Forestry, Fisheries and the Environment (DFFE). The Department is re-processing and replacing data to ensure everything has the same format and is of the same quality and datasets will be marked as obsoleted once that is done. As such the user assumes the entire risk related to the use of these data in its current state and format. DFFE disclaims all warranties of the data whether expressed or implied, including without limitation, any warranties of merchantability or fitness for a particular purpose. For any concerns regarding the data, the user may decide to liaise with the listed PIs who will share their insight on the data quality, where possible. It is also strongly recommended that the user liaises with the listed PIs regarding their proposed projects to mitigate against duplication of research efforts. |
| Methods | The vessel mounted 75kHz Teledyne RD Instruments ADCP , mounted in the vessel's scientific blister at a depth of 4m,was set to collect data for the duration of the voyage. Data was recorded using the Teledyne RDI VMDAS (version 1.46) software. A blanking distance of 8m was used, with the bin size of 8m.The Short Term Averaged (STA) data, set to a 3 minute average, was processed and edited using the AquaVision ViSea DAS and ViSea DPS software. Data was then exported to text files. All velocity data is in m/s. |
| Data | |
| Temporal extent | 01 Dec 2014 – 19 Dec 2014 |
| Geographic extent |
Slangkop, Cape Town, Western Cape, Port Edward, KwaZulu-Natal, South Africa
North: -30.0 |
| Keywords | Algoa, Algoa 213, INDIAN OCEAN, SADCP, Shipboard Acoustic Doppler Current Profilers, SOUTH ATLANTIC OCEAN |
| Related resources |
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