Title Processed CTD continuous observations from the West Coast Hake Biomass Survey on the Africana Voyage 054, June 1987
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 downcast Conductivity-Temperature-Depth (CTD) continuous data collected between 16 June and 10 July 1987, during the West Coast Hake Biomass Cruise on the Africana Voyage 054, in 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 scientific targets of the trip revolved around the determination of biomass index of both Cape hake species off the South African west coast. The diurnal cycle of Cape hake and their relationship with environmental parameters was also studied. Some hake material were collected in South West African waters. Deep-water trawls were made to delimit the offshore extent of hake distribution and to collect rare specimens of fish for accession to museums. Demersal community interrelationships were studied, as were spatial distribution patterns and spawning fractions of round herring.
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 16 Jun 1987 – 10 Jul 1987
Geographic extent

Benguela Current Large Marine Ecosystem (BLMCE)

North: -29.0
South: -36.5
West: 14.0
East: 20.5

Vertical extent Max: -476.7 m
Min: -1.0 m
Keywords Africana, Africana 054, Conductivity, CTD, Depth, Neil Brown CTD, SOUTH ATLANTIC OCEAN, Temperature
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