| Title | Processed CTD continuous observations from the Pelagic Fish Biomass Survey on the Africana Voyage 078, November 1989 |
|---|---|
| Project | Pelagic Biomass Survey |
| Authors |
Gavin Tutt Tarron Lamont |
| Publisher | Department of Forestry, Fisheries and the Environment (2023) |
| Contributors |
Contact Person: Gavin Tutt |
| Abstract | Here we present processed downcast Conductivity-Temperature-Depth (CTD) continuous data collected between 07 November and 30 November 1989 during Voyage 078 on the FRS Africana, in the Benguela Current Large Marine Ecosystem (BCLME) region on the west coast and the Agulhas Current Large Marine Ecosystem (ACLME) region on the south coast of Southern Africa. Neil Brown MK3 and MK4 CTD instruments were used to measure pressure, temperature and conductivity through the water column during research and monitoring cruises between 1983 and 2000. The objectives of the Pelagic Fish Biomass Survey were to conduct an estimation of the biomass and population structure of anchovy, pilchard and round herring off South Africa by means of echo-integration and midwater trawling; to conduct an estimation of anchovy biomass by means of the egg production method; to describe the distribution and behaviour patterns of commercially harvested epi-pelagic and meso-pelagic fish, and the influence of oceanographic variables on these; to collect biological data on reproduction, condition and diet of pelagic fish species; to conduct an examination of the distribution, abundance and production of zooplankton in relation to the environment and to pelagic fish distribution, condition, diet and spawning activity; and lastly to conduct a profiling of currents by means of the Acoustic Doppler Current Profiler (ADCP). |
| Methods | Neil Brown MK3 and MK4 Conductivity-Temperature-Depth (CTD) instruments were used to measure pressure, temperature and conductivity through the water column during research and monitoring cruises between 1983 and 2000. Temperature was converted from the IPTS-68 scale to the ITS-90 scale, and salinity was computed from conductivity measurements on the 1978 Practical Salinity Scale, according to UNESCO (1991) algorithms. UNESCO (1993) quality control procedures were applied to the data, and obvious erroneous values resulting from problems including electronic spikes, data collection in air, inadequate flow through the conductivity cell, among others, have been removed. Any additional calibrations or corrections have been specified in each data file, where applicable and available. |
| Data | |
| Temporal extent | 11 Nov 1989 – 26 Nov 1989 |
| Geographic extent |
Benguela Current Large Marine Ecosystem (BCLME), Agulhas Current Large Marine Ecosystem (ACLME)
North: -33.0 |
| Vertical extent |
Max: -1013 m Min: -1 m |
| Keywords | Africana, Africana 078, Conductivity, CTD, Depth, INDIAN OCEAN, Neil Brown CTD, SOUTH ATLANTIC OCEAN, Temperature |
| Related resources |
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