Title Processed CTD discrete observations from the West Coast Hake Biomass Survey on the Africana Voyage 059, February 1988
Project West Coast Hake Biomass
Authors

Gavin Tutt
Oceans and Coastal Research, Department of Forestry, Fisheries and the Environment (DFFE); role: Marine Scientific Technician; contact details: email: Gtutt@environment.gov.za

Tarron Lamont
Oceans and Coastal Research, Department of Forestry, Fisheries and the Environment (DFFE); role: Marine Scientist; contact details: email: tlamont@environment.gov.za

Publisher Department of Forestry, Fisheries and the Environment (2023)
Contributors

Contact Person: Gavin Tutt
Oceans and Coastal Research, Department of Forestry, Fisheries and the Environment (DFFE); role: Marine Scientific Technician; contact details: email: gtsglider@gmail.com

Contact Person: Tarron Lamont
Oceans and Coastal Research, Department of Forestry, Fisheries and the Environment (DFFE); role: Marine Scientist; contact details: email: tarron.lamont@gmail.com

Abstract Here we present processed Conductivity-Temperature-Depth (CTD) discrete data from the upcast collected between 02 February and 25 February 1988, during the West Coast Hake Biomass Cruise on the Africana Voyage 059, in the southern part of the Benguela Current Large Marine Ecosystem (BCLME) region on the west coast of South 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 main objective of the cruise was to survey by means of trawling the abundance of adult and recruiting hake in South African waters; to investigate the diurnal cycle of hake and other demersal species; to make some experimental trawls in deep water to collect deep-water specimens of fish and squid; to collect routine biological material on demersal species from South West African waters; to investigate the occurence, distribution and abundance of squid and squid larvae; to study demersal community interrelationships and to study the biology of sharks and skates. Oceanographic research assistants were also trained.
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
Attribution-ShareAlike 4.0 International (CC BY-SA 4.0)
Temporal extent 02 Feb 1988 – 24 Feb 1988
Geographic extent

Benguela Current Large Marine Ecosystem (BCLME)

North: -26.5
South: -36.0
West: 14.0
East: 20.0

Vertical extent Max: -501.7 m
Min: 0.0 m
Keywords Africana, Africana 059, Conductivity, CTD, Depth, Neil Brown CTD, SOUTH ATLANTIC OCEAN, Temperature
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