Please note that this is a staging site.
168 datasets found Page 5 of 7
DOI: 10.15493/DEA.MIMS.57072024
South Coast Demersal Biomass Survey on the Africana Voyage 102, April 1992

The South Coast Demersal Biomass Survey was conducted on the Africana Voyage 102 from 31 March to 21 April 1992. The objectives of the cruise were to conduct a random stratified bottom trawl survey to assess the biomass, abundance, and distribution of hake, sole, horse mackerel, squid and other trawl species; to investigate the hydrology and current profiles of the South Coast and to relate this to the distribution of the major demersal trawl species. This included five transects extending from specified areas on the South Coast and approximately perpendicular to the coastline outwards toward the main stream of the Agulhas Current; to survey acoustically the major squid spawning grounds to determine the extent of aggregation of squid shoals at the time of the year; to do a selected number of mid-water trawls to test for the abundance of kingklip and hake and other demersal species as close as possible to the bottom and in midwater over grounds normally inaccessible to bottom trawl...

DOI: 10.15493/DEA.MIMS.54072024
Pelagic Pre-Recruit Mesopelagic Biomass Survey on the Africana Voyage 101, March 1992

The Pelagic Pre-Recruit Mesopelagic Biomass Survey was conducted on the Africana Voyage 101 from 11-23 March 1992. The objectives of the cruise were to get an estimation of the biomass and population structure of pelagic pre-recruit fish off the West Coast by means of echo-integration and midwater trawling; to get an estimation of a pelagic pre-recruit biomass index using quantitative Methot trawls; to get an an estimation of the biomass and population structure of mesopelagic fish using echo-integration and midwater trawling; to investigate the behaviour of pelagic pre-recruit fish in relation to oceanographic variables; to collect biological material for age, oil content, diet and condition studies on pelagic pre-recruits; to profile currents by means of the acoustic doppler current profiler; and to test the feasibility of using a towed transducer for the acoustic assessment of pelagic pre-recruits.

DOI: 10.15493/DEA.MIMS.51072024
West Coast Hake Biomass Survey on the Africana Voyage 100, February 1992

The West Coast Hake Biomass Survey was conducted on the Africana Voyage 100 from 06 February to 03 March 1992. The objectives of the cruise were to survey by means of bottom trawling the abundance of hake and other demersal species on the West Coast of South Africa; to investigate the environmental and ecological interrelationships of hake and other demersal species; to study the biology of chondrichthyan species; to investigate zooplankton scattering layers and their influence on the feeding behaviour and distribution of small hake; to investigate the feasibility of using carbon and nitrogen isotopes for tracing hake diet; to obtain coverage of chlorophyll-fluorescence distribution at the sea surface as part of an on going monitoring program; to investigate aspects of the feeding, dynamics and reproduction of zooplankton; to obtain information on the hydrology and currents on the West Coast; and to investigate vertical and horizontal distribution of hake south west of Cape Point...

DOI: 10.15493/DEA.MIMS.48072024
Agulhas Bank Boundary Processes on the Africana Voyage 099, January 1992

The Agulhas Bank Boundary Processes was conducted on the Africana Voyage 099, from 07-28 January 1992. The objectives of the cruise were to study the entrainment/loss of biota (fish eggs, larvae and plankton) along the shelf and shelf-edge by currents. This was undertaken by means of Acoustic Doppler Current Profilers (ADCP; current) measurements, and regular collection of biota with a combined bongo/calVET net with u³; to estimate the flux of the Agulhas Current along two lines by means of Conductivity, Temperature, Depth (CTD) and Expendable Bathythermograph (XBT) sections, and ADCP measurements; identification of pulses in the Agulhas Current by means of remote sensing (on board) and possible additional CTD/XBT lines to those shown in the grid map. Also a similar study of major filaments on the West Coast; to contribute to studies on the Agulhas Current influence on the South East coast shelf regions, in particular a) the Algoa Bay ecosystem, and b) the St Francis Bay ecosystem...

DOI: 10.15493/DEA.MIMS.45072024
Pelagic Fish Biomass Survey on the Africana Voyage 097, November 1991

The Pelagic Fish Biomass Survey was conducted on the Africana Voyage 097 from 07 November to 03 December 1991. The objectives of the cruise were to estimate the biomass and population length structure of anchovy, pilchard, and round herring off South Africa by means of echo-integration and midwater trawling; to estimate anchovy biomass by means of the egg production method, and trial estimate pilchard 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 determine phytoplankton biomass in the nanophytoplankton (<10 µm) and netphytoplankton (>10 µm) size-classes in surface waters; to obtain information on the distribution and abundance of meso-zooplankton; to estimate secondary production rates of adult copepods using the egg...

DOI: 10.15493/DEA.MIMS.42072024
Horse Mackerel Hydroacoustic Pilot Survey on the Africana Voyage 096, October 1991

The Horse Mackerel Hydroacoustic Pilot Survey was conducted on the Africana Voyage 096 from 14-28 October 1991. The objectives of the cruise were to test the feasibility of obtaining an acoustic estimate of adult horse mackerel; to assess the ability to determine target detectability, target identification and target strength; to obtain an estimate of horse mackerel abundance in a sub-region. The size of the sub-region were to be determined by the time available and on the results of the first two objectives; to collect biological data pertaining to horse mackerel; to measure currents by means of the Acoustic Doppler Current Profilers (ADCP) in order to: a) test for relationships between horse mackerel movement and near-surface and mid-water currents, and b) to add to the ADCP data base for the South East coast; to measure thermal and salinity structure of the water column using a Conductivity, Temperature, Depth (CTD), and measurement of basic biotic parameters; oxygen, nutrients...

DOI: 10.15493/DEA.MIMS.21072024
South Coast Demersal Biomass Survey on the Africana Voyage 095, September 1991

The South Coast Demersal Biomass Survey on the Africana Voyage 095 was conducted on 12 September 1991 to 3 October 1991. The main objective of the survey was to conduct a random stratified bottom trawl survey to assess the biomass, abundance and distribution of hake, sole, horse mackerel, squid and other trawl species with emphasis on 'inshore' fishing areas for recruitment estimates; to investigate the hydrology and current profiles of the South Coast and to relate this to the distribution of the major demersal trawl species; this included five transects extending from specified areas on the South Coast and approximately perpendicular to the coastline out towards the mainstream of the Agulhas Current. A CTD grid in the Cape St Francis area was also done; to do a selected number of midwater trawls to test for the abundance of kingklip and hake and other demersal species as close as possible to the bottom and in midwater over grounds normally inaccessible to bottom trawl gear; to do...

DOI: 10.15493/DEA.MIMS.15072024
Anchovy Recruitment Survey on the Africana Voyage 092, May 1991

The Anchovy Pilchard Recruitment Survey on the Africana Voyage 092 was conducted on the 7 to the 24 May 1991. The main objectives of the cruise were to estimate the abundance and size-structure of anchovy; a description of the distribution and behaviour patterns of anchovy and pilchard of recruits and the oceanographic variables on these; a collection of biological data on pelagic fish species; an examination of the distribution, abundance and production of plankton in relation to the environment and to recruit distribution and condition; an examination of feeding ecology and food selection of pilchard recruits; an investigation of the vertical distribution and behaviour of feeding juvenile hake in relation to their food environment; an examination of the feasibility of mackerel collecting live horse with the midwater trawl, and of keeping them alive on board and the retrieval of a current meter mooring off Hondeklip Bay.

DOI: 10.15493/DEA.MIMS.36072024
Pelagic Pre-Recruit Mesopelagic Biomass Survey on the Africana Voyage 090, March 1991

The Pelagic Pre-Recruit Mesopelagic Biomass Survey was conducted on the Africana Voyage 090 from 05-19 March 1991. The objectives of the cruise were to get an estimation of the biomass and population structure of epi-pelagic pre-recruit fish off the West Coast by means of echo-integration and midwater trawling; get an estimation of an epi-pelagic pre-recruit biomass index using quantitative Methot trawls; get an estimation of the biomass and population structure of mesopelagic fish using echo-integration and midwater trawling; to investigate the behaviour of pelagic pre-recruit fish in relation to oceanographic variables; get a collection of biological material for age, oil content, diet and condition studies on pelagic pre-recruits; to determine oxygen concentrations in rock lobster distribution areas; the profiling of currents by means of the acoustic doppler current profiler; and testing the feasibility of the acoustic assessment of juvenile hake.

DOI: 10.15493/DEA.MIMS.33072024
Plankton Dynamics on the Africana Voyage 089, February 1991

The Plankton Dynamics cruise on the Africana Voyage 089 was conducted from 12-23 February 1991. The objectives of the cruise were to complete a summer transect to provide information on zooplankton vertical migration patterns during the period of maximum upwelling; to contrast hydrological and planktological conditions across the shelf just north of the Columbine divergence, at a time when pelagic fish larvae transported in the jet current were crossing the shelf to the nursery area; to measure rates of primary and secondary production in different size classes of planktonic organisms at offshore (shelf-break), mid shelf and inshore locations; to examine the influence of recent feeding history on the condition of pre-recruit pelagic fish; to measure time-dependent fluctuations in the currents using the acoustic doppler current profiler; and to make measurements of nitrogen dynamics within the planktonic community.

DOI: 10.15493/DEA.MIMS.30072024
West Coast Hake Biomass Survey on the Africana Voyage 088, January 1991

The West Coast Hake Biomass Survey was conducted on the Africana Voyage 088 from 07-29 January 1991. The objectives of the cruise were to survey by means of bottom trawling the abundance of hake and other demersal species on the West Coast of South Africa; to investigate the environmental and ecological interrelationships of hake and other demersal species; to investigate the possible recovery of the stocks of West Coast Sole; to study the biology of chondrichthyan species; to collect material for the electrophoretic comparison of the southern African kingklip, Genypterus capensis, with the Australian G. blacodes and G. microstomus and the South American G. blacodes and G. chilensis; to investigate zooplankton scattering layers and their influence on the feeding behaviour and distribution of small hake; training of Oceanographic Research Assistants; to investigate the feasibility of using carbon and nitrogen isotopes for tracing hake diet; to obtain coverage of...

DOI: 10.15493/DEA.MIMS.09122024
South Coast Demersal Biomass Survey on the Africana Voyage 086, September 1990

South Coast Demersal Biomass Survey was conducted on the Africana Voyage 086 from 07 September - 02 October 1990. The objectives of the cruise were to survey by means of bottom trawling (under 200 m) the abundance and distribution of adult and juvenile hake, sole, squid, horse mackerel and other demersal target species and to make biomass estimates of each; to study the hydrological environment using the CTD and ADCP and to relate this information to the catches of hake , sole, squid, horse mackerel and other trawl species. The investigation included hydrological transects off the Eastern Cape Coast from inside the bay areas outwards to the shelf -break or main Agulhas stream; a pilot survey using a Calvet net to investigate the feasibility of determining sole egg distribution for the egg production technique; data on the eggs and larvae of other species were also collected. A study was also conducted on demersal community relationships, particularly of chondrichthyians and...

DOI: 10.15493/DEA.MIMS.24072024
West Coast Hake Biomass Survey on the Africana Voyage 084, July 1990

The West Coast Hake Biomass Survey was conducted on the Africana Voyage 084 from 12 July - 06 August 1990. The objectives of the cruise were to survey by means of trawling the abundance of adult and recruiting hake in South African waters; to investigate diurnal cycle of hake and other demersal species; to investigate the environmental and ecological interrelationships of hake and other demersal species; to investigate the occurrence, distribution, and abundance of squid; to study the biology of chondrichthyan species; to investigate zooplankton scattering layers and their influence on the feeding and distribution of small hake; to investigate the feasibility of using carbon and nitrogen isotopes for tracing hake diet; to obtain extensive coverage of chlorophyll-fluorescence distribution at the sea surface as part of an ongoing monitoring program; to collect live chaetognaths and medusae for gut evacuation and feeding experiments, and for gut content analysis; and lastly to train...

DOI: 10.15493/DEA.MIMS.12072024
South Coast Demersal Biomass Survey on the Africana Voyage 082, May 1990

The South Coast Demersal Biomass Survey on the Africana Voyage 082 was conducted from 23 May - 13 June 1990. The objectives of the cruise were to survey by bottom-trawling the abundance of adult and recruiting hake, sole and other trawl target species; to make experimental bottom-trawls in deep water to establish the limit of hake distribution, and to collect deep-water specimens of fish and squid; to investigate the environment and ecological interrelationships of hake and other demersal species in the various depth strata; to study demersal community relationships; to investigate the occurrence, distribution and abundance of squid and squid larvae; to investigate the occurrence of line fish species in shallow waters; to study the biology of sharks and skates; to study the biology of kob; and to train senior staff and oceanographic research assistants.

DOI: 10.15493/DEA.MIMS.08072024
Anchovy Recruitment Survey on the Africana Voyage 081, May 1990

The Anchovy Recruitment Survey on the Africana Voyage 081 was conducted from 07-12 May 1990. The objectives of the survey were to attain an estimation of the abundance and size-structure of anchovy recruits; describe the distribution and behaviour patterns of anchovy recruits and the influence of oceanographic variables on these; collect biological data on pelagic fish species; examine the distribution, abundance and production of zooplankton in relation to the environment, and to recruit distribution and condition; and the profiling of currents by means of the acoustic doppler current profiler.

DOI: 10.15493/DEA.MIMS.11882023
Pelagic Fish Biomass Survey on the Africana Voyage 078, November 1989

The Pelagic Fish Biomass Survey was conducted on the Africana Voyage 078 from 7 - 30 November 1989. The objectives of the cruise 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).

DOI: 10.15493/DEA.MIMS.11872023
Physical-Chemical Oceanography Cruise on the Africana Voyage 077, September 1989

The Physical-Chemical Oceanography Cruise was conducted on the Africana Voyage 077, from 11 - 22 September 1989. There were several objectives to this cruise, covering Physical Environment (PE), Sedimentation and Nutrient cycling (SN), Chemical Environment (CE), Shoal Ecology (SE), Plankton studies (P) and testing of the new AIDA acoustic system with possible estimates of biomass in specific places such as in the baroclinic jets. The cruise objectives included identifying and documenting near-surface and mid-water baroclinic jets west of Cape Columbine and Cape Town using acoustic doppler profiling and Conductivity-Temperature-Depth (CTD) data; observing currents in the upper 200m at regular intervals along the cruise track, using the Acoustic Doppler Current Profiler (ADCP); performing a 30 hour internal tide experiment at the shelf edge west of the Chamais Bay; deploying a series of current meter moorings on the Namibian remote shelf and eastern Cape Basin zones between Chamais...

DOI: 10.15493/DEA.MIMS.11862023
West Coast Hake Biomass Survey on the Africana Voyage 075, July 1989

The West Coast Hake Biomass Survey on the Africana Voyage 075 was conducted from 14 July - 17 August 1989. The objectives of the cruise were 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 investigate the environmental and ecological interrelationships of hake and demersal species; to make some experimental trawls in deep water to determine hake distribution limits and 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; to study the biology of sharks and selected non-commercial fish species; to investigate zooplankton scattering layers and their influence on the feeding behaviour of small hake and to extend the primary production data further...

DOI: 10.15493/DEA.MIMS.11852023
South West African Pilchard and Anchovy Biomass Survey on the Africana Voyage 074, June 1989

The South West African Pilchard and Anchovy Biomass Survey was conducted on the Africana Voyage 074 from 22 June - 4 July 1989. The objectives of the survey were to undertake an acoustic / trawling survey of the pilchard stock off SWA and arrive at a stock estimate; to survey the horse-mackerel and anchovy stocks off South West Africa (SWA) and obtain stock estimates if possible and to collect the environmental information on the habitat of the above species primarily by means of Conductivity-Temperature-Depth (CTD) and U³ dips in the upper 200m.

DOI: 10.15493/DEA.MIMS.11842023
Anchovy Recruitment Survey on the Africana Voyage 073, June 1989

The Anchovy Recruitment Survey was conducted on the Africana Voyage 073 from 8 - 22 June 1989. The survey objectives were to assess anchovy recruitment strength in South African waters in order to recommend a final quota for the 1989 RSA anchovy fishing season; to collect data for the determination of the target strength of anchovy and other pelagic and mesopelagic species; to collect data on shoaling behaviour of pelagic fish, specifically anchovy, pilchard and red-eye; to investigate relationships between the distribution of pelagic fish, zooplankton and water temperature; to determine standing stocks of phytoplankton and zooplankton in different regions and to estimate copepod secondary production in these regions through egg-production and moulting rate experiments.

DOI: 10.15493/DEA.MIMS.01112024
South Coast Demersal Biomass Survey on the Africana Voyage 072, May 1989

The South Coast Demersal Hake Biomass Survey was conducted on the Africana Voyage 072 from 10 May to 29 May 1989. The objectives of the cruise were to survey by means of bottom-trawling the abundance of adult and recruiting hake, sole and other trawl target species; to make experimental bottom-trawls in deep water to collect deep-water specimens of fish and squid; to test the feasibility of an acoustic assessment of horse mackerel; to investigate the environment and ecological interrelationships of hake and other demersal species in the various depth strata; to study demersal community relationships; to investigate the occurrence, distribution and abundance of squid and squid larvae; to investigate the occurrence of line fish species in shallow waters; to study the biology of sharks and skates; and to train Oceanographic Research Assistants.

DOI: 10.15493/dea.mims.26052259
South African National Antarctic Expedition (SANAE) on the SA Agulhas II Voyage 014, December 2014

The South African National Antarctic Expedition (SANAE) is an annual cruise undertaken by the Department of Environmental Affairs (DEA) to change the overwintering teams in Antarctica and to replenish the supplies at the SANAE IV Research base. This voyage was to deliver the SANAE 54 team to the island and return with the SANAE 53 team. The cruise was undertaken between 14 December 2014 and 19 February 2015 with full scientific complement.

DOI: 10.15493/DEA.MIMS.11822023
Physical-Chemical Oceanography Cruise on the Africana Voyage 070, March 1989

The Physical-Chemical Oceanography Cruise was conducted on the Africana Voyage 070 from 2 - 11 March 1989. The objectives of the cruise were to retrieve six acoustic current meters deployed in September 1988; to recover and redeploy the sequentially sampling sediment trap and the two Anderaa current meters incorporated on the array at a position 90 miles west of Walvis Bay; to repeat a line of Conductivity-Temperature-Depth (CTD) stations running at right angles to the shelf from the 4000m Cape Basin station towards Conception Bay; to take size-fractional chlorophyll samples at 3-hourly intervals to calibrate the in-line fluorometer in the hydro lab; to collect a Pygmy Right Whale for Peter Best and rare sharks for Len Compagno from Walvis Bay and to exchange scientific equipment at Walvis Bay for the SWA (Namibia) section.

DOI: 10.15493/DEA.MIMS.11812023
West Coast Hake Biomass Survey on the Africana 069, January 1989

The West Coast Hake Biomass Survey was conducted on the Africana 069 from 5 - 26 January 1989. The cruise was multi-disciplinary. The main target was to determine, by means of the swept area method, the present status of the hake resource on the South African west coast. In carrying out this study, it was possible also to collect some information on the environment and zooplankton (including squid larvae) in the vicinity of the catches and to determine some ecological interrelationships of hake and other demersal fish species, to investigate squid distribution, to study some aspects of the biology and distribution of sharks and skates, to study the feeding ecology of demersal species of little commercial importance and to look closely at demersal communities. A diurnal study was also carried out successfully and some deep-water trawls were made to collect rare and interesting specimens. While in South West African waters, a comparison of the trawling capabilities of the M.F.V....

DOI: 10.15493/DEA.MIMS.11802023
Physical-Chemical Oceanography Cruise on the Africana Voyage 067, September 1988

The Physical-Chemical Oceanography Cruise was conducted on the Africana Voyage 067 from 14 - 30 September 1988. This cruise was divided into two legs with the first leg focusing on physical oceanography and the latter on chemical oceanography. The purpose of the first leg of the cruise was primarily to moor current meters and water-level recorders at various sites, mostly north of the Orange River, and to obtain a precise set of Conductivity-Temperature-Depth (CTD) data on a line running normal to the topography from a point in 4200m of water into Conception Bay. The CTD data will be used to calculate water flux along the shelf using inverse techniques. The objectives of the second leg included deploying the Kriel sequential sediment trap west of Walvis Bay, recovering Sea Fisheries Research Institute (SFRI) sediment traps deployed in the first half of the cruise, investigating trends in primary production in the vicinity of the Kriel trap mooring and around upwelling centres using...

168 datasets found Page 5 of 7

Geographic extent

Temporal extent