Title Processed CTD discrete observations from the West Coast Hake Biomass Survey on the Africana Voyage 015, January 1984
Project West Coast Hake Biomass
Authors

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

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 (2022)
Contributors

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

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 This is processed CTD discrete data from the upcast collected during the West Coast Hake Biomass Survey on the Africana Voyage 015 from 05 - 31 January 1984. The cruise operated in the Benguela Current Large Marine Ecosystem (BCLME) region on the west coast of South Africa. The purpose of this cruise was to survey by means of trawling the abundance of recruiting and adult hake between the Orange River and longitude 20° E. The objectives also included investigating the diurnal cycle of hake and other demersal species, to compare the trawling results of R.S. Africana with those of M.F.V. Chicha Touza, the Spanish trawler used for similar surveys, to investigate the environment of hake and other demersal species and to carry out acoustic target identification of mesopelagic species using RMT 8 nets.
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 05 Jan 1984 – 31 Jan 1984
Geographic extent

Benguela Current Large Marine Ecosystem (BCLME) region on the west coast of South Africa

North: -28.0
South: -36.0
West: 14.0
East: 20.0

Vertical extent Max: -581.2 m
Min: -0.01 m
Keywords Africana, Africana 015, Conductivity, CTD, Depth, Neil Brown CTD, SOUTH ATLANTIC OCEAN, Temperature
Related resources