Resources

RRS Charles Darwin CD156

Cruise summary report

Cruise Info. 
Ship name (ship code)RRS Charles Darwin (74AB)
Cruise identifierCD156
Cruise period2004-04-26 — 2004-05-23
StatusCompleted
Port of departureSanta Cruz de Tenerife, Spain
Port of returnSanta Cruz de Tenerife, Spain
ObjectivesBetween the 26th April and 26th May 2004 Plymouth Marine Laboratory in collaboration with scientists from NIWA, New Zealand, Laboratoire Arago, France and University of East Anglia conducted a two-ship exercise using RRS Charles Darwin and RV Poseidon (see Poseidon cruise PO311) to test the following hypothesis:

'The supply of, and the interaction between, iron and phosphorous control biological activity and fluxes in the subtropical North Atlantic.'

An experimental area in international waters to the west of the Canary Islands was selected following an intense period of vertical and horizontal mapping by the Charles Darwin. Using SF6 as a tracer for amended waters, two separate experiments were performed.

The first (5th - 15th May) involved the addition of 20 tonnes of anhydrous monosodium phosphate at 10 m depth over an area of approximately 25 km2, centred at 27.8N 23.3W.

The second experiment was conducted following a mid-cruise return by the Poseidon to Tenerife between 16th and 22nd May, at 27.5N 22.5W when 5 tonnes of acidified iron sulphate were added over the first 12 hours and, following a 15 hour recovery period, 20 tonnes of phosphate were added on the top of the original iron/SF6 patch. Measurements of nutrient cycling, biogenic gases, and biological activity were monitored prior to and after deployment (IN stations) of the fertilised patches relative to several (OUT) control stations.
Chief scientistNicholas J P Owens (Newcastle University School of Marine Science and Technology)
ProjectFEEP
Cruise reportRRS Charles Darwin CD156 cruise report cd156.pdf (1.19 MB) 
Ocean/sea areas 
GeneralNorth East Atlantic Ocean (limit 40W)
SpecificTropical North Atlantic Ocean
Measurements 
Physical oceanography 
Surface measurements underway (T,S)Quantity: activity duration in days = 29
Description: Underway surface intake measurements of T & S
CTD stationsQuantity: number of profiles = 93
Description: CTD Casts - standard UORS instrumentation - temperature, salinity, transmission, fluorescence
Subsurface temperature and salinity measurementsQuantity: activity duration in hours = 100
Description: Tows of Undulating Oceanographic Recorder (UOR) in and around tracer patches 1 and 2.
Transparency (eg transmissometer)Quantity: number of profiles = 93
Description: CTD Casts - standard UORS instrumentation - temperature, salinity, transmission, fluorescence
Transparency (eg transmissometer)Quantity: number of profiles = 12
Description: Filters collected for measurement of particle absorption from midday CTDs and selected outstations
Optics (eg underwater light levels)Quantity: number of profiles = 45
Description: Optical freefal instrument with 7 band radiance and 7 band irradiance head + depth, tilt and roll
Geochemical tracers (eg freons)Quantity: activity duration in days = 14
Description: Night-time underway surface intake measurements of sulphur hexafluoride
Current profiler (eg ADCP)Quantity: number of profiles = 92
Description: Lowered ACDP RDI 300 kHz, downward looking
Current profiler (eg ADCP)Quantity: number of profiles = 52
Description: Vertical profiles of sulphur hexafluoride taken from Niskins mounted on CTD rosette
Current profiler (eg ADCP)Quantity: activity duration in days = 28
Description: Vessel Mounted ADCP (150 Hz RDI Narrow Band), all processed
Chemical oceanography 
Other dissolved gasesQuantity: number of profiles = 45
Description: Measurements of DMS and DMSP (particulate and dissolved) taken from CTD rosette
Other dissolved gasesQuantity: number of profiles = 38
Description: Measurement of methyl bromide
Other dissolved gasesQuantity: number of experiments = 11
Description: Dilution Grazing Experiments. Measurements of autotrophic cyanobacteria (AFC) , measurements of DMSP production and consumption rates, viral lysis, FFRF, microscopy and chl a
Other dissolved gasesQuantity: number of profiles = 52
Description: Measurements of dissolved volatile organic iodine compounds
PhosphateQuantity: activity duration in days = 12
Description: Night-time underway surface intake measurements of nanomolar phosphate
PhosphateQuantity: number of profiles = 40
Description: Vertical profiles of nanomolar nitrate, nitrite and phosphate taken from CTD rosette
PhosphateQuantity: number of profiles = 34
Description: Vertical profiles of nitrate, nitrite, phosphate and silicate taken from Niskins mounted on CTD rosette
PhosphateQuantity: number of experiments = 5
Description: Dissolved organic matter biodegradation experiments
NitrateQuantity: number of experiments = 5
Description: Dissolved organic matter biodegradation experiments
NitrateQuantity: number of profiles = 40
Description: Vertical profiles of nanomolar nitrate, nitrite and phosphate taken from CTD rosette
NitrateQuantity: number of profiles = 34
Description: Vertical profiles of nitrate, nitrite, phosphate and silicate taken from Niskins mounted on CTD rosette
NitriteQuantity: number of profiles = 40
Description: Vertical profiles of nanomolar nitrate, nitrite and phosphate taken from CTD rosette
NitriteQuantity: number of profiles = 34
Description: Vertical profiles of nitrate, nitrite, phosphate and silicate taken from Niskins mounted on CTD rosette
AmmoniaQuantity: number of profiles = 37
Description: Vertical profiles of nano-molar ammonium from Niskins mounted on CTD rosette
SilicateQuantity: number of profiles = 34
Description: Vertical profiles of nitrate, nitrite, phosphate and silicate taken from Niskins mounted on CTD rosette
Trace elementsQuantity: number of profiles = 33
Description: Dissolved iron measurements taken from Niskins mounted on CTD rosette
Trace elementsQuantity: activity duration in days = 10
Description: Night-time underway iron measurements taken from trace metal fish
Other chemical oceanographic measurementsQuantity: number of profiles = 45
Description: Measurements of DMS and DMSP (particulate and dissolved) taken from CTD rosette
Other chemical oceanographic measurementsQuantity: number of experiments = 11
Description: Dilution Grazing Experiments. Measurements of autotrophic cyanobacteria (AFC) , measurements of DMSP production and consumption rates, viral lysis, FFRF, microscopy and chl a
Other chemical oceanographic measurementsQuantity: number of experiments = 5
Description: Dissolved organic matter biodegradation experiments
Biology and fisheries 
Phytoplankton pigs (eg chlorophyll, fluorescence)Quantity: number of experiments = 11
Description: Dilution Grazing Experiments. Measurements of autotrophic cyanobacteria (AFC) , measurements of DMSP production and consumption rates, viral lysis, FFRF, microscopy and chl a
Phytoplankton pigs (eg chlorophyll, fluorescence)Quantity: number of profiles = 57
Description: Vertical profiles of phytoplankton pigments (via HPLC) taken from CTD rosette
Phytoplankton pigs (eg chlorophyll, fluorescence)Quantity: number of samples = 36
Description: Underway surface intake measurements of HPLC pigments
Phytoplankton pigs (eg chlorophyll, fluorescence)Quantity: number of profiles = 87
Description: Vertical FRRF profiles, instrument mounted on CTD rosette
Phytoplankton pigs (eg chlorophyll, fluorescence)Quantity: number of profiles = 93
Description: CTD Casts - standard UORS instrumentation - temperature, salinity, transmission, fluorescence
Phytoplankton pigs (eg chlorophyll, fluorescence)Quantity: activity duration in days = 12
Description: Night-time underway surface intake FRRF measurements
Phytoplankton pigs (eg chlorophyll, fluorescence)Quantity: number of profiles = 12
Description: Filters collected for HPLC pigment analysis (linked to particle absorption)
Phytoplankton pigs (eg chlorophyll, fluorescence)Quantity: activity duration in days = 29
Description: Underway surface intake fluorescence (samples routinely collected for chlorophyll calibration via HPLC)
Particulate organic matter (inc POC, PON)Quantity: number of profiles = 23
Description: Vertical profiles of particulate nitrogen and particulate phosphorus taken from CTD rosette
Dissolved organic matter (inc DOC)Quantity: number of profiles = 24
Description: Vertical profiles of dissolved organic phosphorus and dissolved organic nitrogen taken from CTD rosette
Dissolved organic matter (inc DOC)Quantity: number of profiles = 23
Description: Vertical profiles of dissolved organic carbon taken from CTD rosette
PhytoplanktonQuantity: number of profiles = 47
Description: Collection of preserved seawater samples taken from CTD rosette for analysis of micro- and nanoplankton via microscopy
PhytoplanktonQuantity: number of profiles = 47
Description: Samples taken from CTD rosette for analysis of nano and picoplankton via flow cytometry (AFC)
Pelagic bacteria/micro-organismsQuantity: number of profiles = 47
Description: Samples taken from CTD rosette for analysis of nano and picoplankton via flow cytometry (AFC)
Pelagic bacteria/micro-organismsQuantity: number of experiments = 11
Description: Dilution Grazing Experiments. Measurements of autotrophic cyanobacteria (AFC) , measurements of DMSP production and consumption rates, viral lysis, FFRF, microscopy and chl a
Pelagic bacteria/micro-organismsQuantity: number of profiles = 47
Description: Samples collected for post-cruise determination of heterotrophic bacteria and viruses from water taken from CTD rosette
Pelagic bacteria/micro-organismsQuantity: number of profiles = 47
Description: Collection of preserved seawater samples taken from CTD rosette for analysis of micro- and nanoplankton via microscopy
Pelagic bacteria/micro-organismsQuantity: number of profiles = 27
Description: Measurement of virus composition, abundance and productivity from samples collected from CTD rosette
Meteorology 
Routine standard measurementsQuantity: activity duration in days = 29
Description: Routine meteorological measurements made by Darwin Met Package
Moorings, landers, buoys 
Physical oceanography 
Subsurface temperature measurements27° 48' 42" N  23° 19' 59" W — Deployment of Thermistor chain 10 * Vemco, 4 * RBR, 4 * RBRD (depths 5 - 170 m ) attached to surface difter drogued at 20 m Deployed 4 May 15:27 - 10 May 20:00 Redeployed 10 May 23:37 - 13 May 13:00 (Patch 1 PO4 only
Subsurface temperature measurements27° 32' 48" N  22° 32' 12" W — Deployment of Thermistor chain 10 * Vemco, 4 * RBR, 4 * RBRD (depths 5 - 170 m ) attached to surface difter drogued at 20 m Deployed 16 May 08:00 - 18 May 19:10 Redeployed 18 May 20:00 - 22 May 13:15 (Patch 2 Fe + PO4)
Surface drifters/drifting buoys27° 32' 48" N  22° 32' 12" W — Deployment of Thermistor chain 10 * Vemco, 4 * RBR, 4 * RBRD (depths 5 - 170 m ) attached to surface difter drogued at 20 m Deployed 16 May 08:00 - 18 May 19:10 Redeployed 18 May 20:00 - 22 May 13:15 (Patch 2 Fe + PO4)
Surface drifters/drifting buoys27° 39' 29" N  23° 19' 54" W — Deployment of second surface drifter for 1 day (Patch 1)
Surface drifters/drifting buoys27° 32' 30" N  22° 34' 12" W — Deployment of FRRF (depth 26m) attached to surface drifter drogued at 20m Deployed 16 May 07:30 - 18 May 18:30 Redeployed 18 May 19:50 - 22 May 13:4
Surface drifters/drifting buoys27° 48' 42" N  23° 19' 59" W — Deployment of Thermistor chain 10 * Vemco, 4 * RBR, 4 * RBRD (depths 5 - 170 m ) attached to surface difter drogued at 20 m Deployed 4 May 15:27 - 10 May 20:00 Redeployed 10 May 23:37 - 13 May 13:00 (Patch 1 PO4 only
Biology and fisheries 
Phytoplankton pigs (eg chlorophyll, fluorescence)27° 32' 30" N  22° 34' 12" W — Deployment of FRRF (depth 26m) attached to surface drifter drogued at 20m Deployed 16 May 07:30 - 18 May 18:30 Redeployed 18 May 19:50 - 22 May 13:4
Data held at BODC Get data
Series/Profiles 
42  Bottle station
Reference numbers
Nitrite concentration parameters in the water column
Phosphate concentration parameters in the water column
Vertical spatial coordinates
Silicate concentration parameters in the water column
Ammonium and ammonia concentration parameters in water bodies
Nitrate concentration parameters in the water column
Quality control flags
Reference numbers
Nitrite concentration parameters in the water column
Phosphate concentration parameters in the water column
Vertical spatial coordinates
Silicate concentration parameters in the water column
Ammonium and ammonia concentration parameters in water bodies
Nitrate concentration parameters in the water column
Quality control flags

BODC idDate/TimeLocationDoc.
13531362004-05-01 18:11 28° 25' 5" N  24° 22' 26" W  View metadata report for BODC series reference number 1353136
13531612004-05-04 08:56 27° 48' 42" N  23° 19' 51" W  View metadata report for BODC series reference number 1353161
13531972004-05-07 08:05 27° 43' 13" N  23° 13' 20" W  View metadata report for BODC series reference number 1353197
13533082004-05-11 10:24 27° 41' 32" N  23° 19' 37" W  View metadata report for BODC series reference number 1353308
13534742004-05-20 08:26 27° 38' 23" N  22° 15' 0" W  View metadata report for BODC series reference number 1353474
13534982004-05-21 11:55 27° 40' 18" N  22° 12' 28" W  View metadata report for BODC series reference number 1353498
13531732004-05-05 19:33 27° 47' 18" N  23° 18' 36" W  View metadata report for BODC series reference number 1353173
13532282004-05-08 11:10 27° 41' 4" N  23° 14' 14" W  View metadata report for BODC series reference number 1353228
13532652004-05-09 15:36 27° 47' 30" N  23° 13' 54" W  View metadata report for BODC series reference number 1353265
13533942004-05-15 07:32 27° 36' 55" N  23° 14' 16" W  View metadata report for BODC series reference number 1353394
13534012004-05-16 04:50 27° 32' 24" N  22° 34' 16" W  View metadata report for BODC series reference number 1353401
13534492004-05-19 12:01 27° 40' 23" N  22° 16' 41" W  View metadata report for BODC series reference number 1353449
13531482004-05-03 10:33 27° 48' 36" N  23° 20' 0" W  View metadata report for BODC series reference number 1353148
13532892004-05-11 06:23 27° 39' 55" N  23° 21' 19" W  View metadata report for BODC series reference number 1353289
13533212004-05-11 12:24 27° 40' 37" N  23° 20' 18" W  View metadata report for BODC series reference number 1353321
13533692004-05-13 16:48 27° 45' 3" N  23° 23' 42" W  View metadata report for BODC series reference number 1353369
13534372004-05-19 07:22 27° 39' 26" N  22° 18' 45" W  View metadata report for BODC series reference number 1353437
13535052004-05-22 07:29 27° 42' 4" N  22° 3' 27" W  View metadata report for BODC series reference number 1353505
13530812004-04-29 04:17 26° 45' 10" N  23° 28' 2" W  View metadata report for BODC series reference number 1353081
13532772004-05-10 07:57 27° 39' 28" N  23° 13' 19" W  View metadata report for BODC series reference number 1353277
13533572004-05-12 07:19 27° 39' 51" N  23° 22' 3" W  View metadata report for BODC series reference number 1353357
13534252004-05-17 13:50 27° 34' 6" N  22° 27' 31" W  View metadata report for BODC series reference number 1353425
13535172004-05-22 11:54 27° 47' 10" N  22° 2' 53" W  View metadata report for BODC series reference number 1353517
13531002004-04-29 18:53 26° 8' 20" N  23° 23' 43" W  View metadata report for BODC series reference number 1353100
13532412004-05-08 16:07 27° 41' 28" N  23° 3' 0" W  View metadata report for BODC series reference number 1353241
13532902004-05-11 08:12 27° 42' 46" N  23° 18' 14" W  View metadata report for BODC series reference number 1353290
13534862004-05-21 07:22 27° 40' 17" N  22° 12' 40" W  View metadata report for BODC series reference number 1353486
13530682004-04-28 14:27 27° 57' 54" N  23° 26' 23" W  View metadata report for BODC series reference number 1353068
13531122004-04-30 08:46 24° 49' 19" N  24° 49' 31" W  View metadata report for BODC series reference number 1353112
13531242004-05-01 10:08 27° 48' 12" N  25° 1' 10" W  View metadata report for BODC series reference number 1353124
13531852004-05-06 07:33 27° 45' 22" N  23° 16' 48" W  View metadata report for BODC series reference number 1353185
13532162004-05-07 16:10 27° 44' 11" N  23° 21' 9" W  View metadata report for BODC series reference number 1353216
13533452004-05-11 18:58 27° 39' 20" N  23° 22' 10" W  View metadata report for BODC series reference number 1353345
13533822004-05-14 15:09 27° 41' 9" N  23° 11' 30" W  View metadata report for BODC series reference number 1353382
13534622004-05-19 18:30 27° 40' 4" N  22° 22' 51" W  View metadata report for BODC series reference number 1353462
13530932004-04-29 10:28 26° 42' 39" N  22° 43' 56" W  View metadata report for BODC series reference number 1353093
13532042004-05-07 13:45 27° 44' 2" N  23° 13' 26" W  View metadata report for BODC series reference number 1353204
13532532004-05-09 07:49 27° 41' 30" N  23° 13' 44" W  View metadata report for BODC series reference number 1353253
13533332004-05-11 14:21 27° 39' 50" N  23° 21' 18" W  View metadata report for BODC series reference number 1353333
13533702004-05-14 07:37 27° 37' 5" N  23° 16' 25" W  View metadata report for BODC series reference number 1353370
13534132004-05-17 07:20 27° 33' 12" N  22° 29' 33" W  View metadata report for BODC series reference number 1353413
13534502004-05-19 14:58 27° 40' 18" N  22° 23' 10" W  View metadata report for BODC series reference number 1353450
Discrete samples 
80  All plastic clean surface pumped supplyDissolved metal concentrations in the water column
93  CTD frame plus rosette samplerTransmittance and attenuance of the water column
Carotenoid and flavenoid pigment concentrations in water bodies
Nitrite concentration parameters in the water column
Phytoplankton taxonomic abundance in water bodies
Phosphate concentration parameters in the water column
Salinity of the water column
Temperature of the water column
Dissolved oxygen parameters in the water column
Total metal concentrations in water bodies
Concentration of suspended particulate material in the water column
Silicate concentration parameters in the water column
Visible waveband radiance and irradiance measurements in the water column
Bacteria generic abundance in water bodies
Phytoplankton generic abundance in water bodies
Density of the water column
Virus abundance in water bodies
Ammonium and ammonia concentration parameters in water bodies
Electrical conductivity of the water column
Nitrate concentration parameters in the water column
Chlorophyll pigment concentrations in water bodies
Dissolved metal concentrations in the water column
1275  Sample taken from ship's non-toxic supplyPhosphate concentration parameters in the water column
Chlorophyll pigment concentrations in water bodies