| Title | Processed CTD 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 processed Conductivity, Temperature, Depth (CTD) 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 CTD raw data was converted to scientific units using SBEDataProcessing software (ver 7.26.7.114). The following modules (SBEDataProcessing) were then run on the converted data using the recommended default values: Align CTD, Filter, Loop Edit and Cell Thermal Mass. The data was then split into the up cast and the down cast. The down cast data was then bin averaged on pressure, every 1db. This was then imported into MS-Excel together with the casts metadata. Some quality control was then performed using the Ocean Data View software to identify outliers in the data. These outliers were then removed from both the .CNV files created by the SeaBird software and the Excel spreadsheet. |
| 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, Conductivity, CTD, Depth, INDIAN OCEAN, SOUTH ATLANTIC OCEAN, Temperature |
| Related resources |
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