RRS Discovery DY086 (COMICS)
Cruise summary report
| Cruise Info. | |
| Ship name (ship code) | RRS Discovery (74EQ) |
| Cruise identifier | DY086 (COMICS) |
| Cruise period | 2017-11-12 — 2017-12-19 |
| Status | Completed |
| Port of departure | Stanley, Falkland Islands (Malvinas) |
| Port of return | Stanley, Falkland Islands (Malvinas) |
| Purpose | Research |
| Objectives | This is one of two cruises aimed at evaluating the controls over mesopelagic remineralisation depth. This is the depth to which material sinks when it leaves the surface ocean, a factor we know to be a critical control over climate. There are three serious hypotheses explaining what controls this depth; plankton community structure, temperature and oxygen concentrations. COMICS will test two of these; oxygen and community structure with this cruise exaimining the role of community structure; more precisely how the evolution of community structure over the course of the bloom affects sinking depth.
In order to evaluate this three long stations of about a week duration each were worked over a 1 mo period between mid Nov and mid Dec in the major plankton bloom which occurs NW of South Georgia. At each station surface community structure and a variety of metrics of downward particle flux were measured, together with estimates of the biomass and growth rates of the major taxonomic classes of organisms responsible for consuming sinking material. All operations were conducted in the vicinity of BAS station P3 (52 40 S, 40 06 W). |
| Chief scientist | Richard Sanders (National Oceanography Centre, Southampton) |
| Project | Controls over Ocean Mesopelagic Carbon Storage (COMICS) |
| Cruise report |  (57.86 MB) |
| Ocean/sea areas | |
| General | South West Atlantic Ocean (limit 20W) |
| Specific | South Georgia |
| Track charts | (0.17 MB) |
| Measurements | |
| Physical oceanography | |
| Surface measurements underway (T,S) | Quantity: activity duration in days = 40 Description: Underway Sampling |
| CTD stations | Quantity: number of profiles = 15 Description: Trace Metal CTD casts |
| CTD stations | Quantity: activity duration in days = 60 Description: Gliders |
| Transparency (eg transmissometer) | Quantity: number of deployments = 30 Description: Red Camera Frame |
| Optics (eg underwater light levels) | Quantity: number of deployments = 30 Description: Red Camera Frame |
| Current profiler (eg ADCP) | Quantity: activity duration in days = 40 Description: Underway Sampling |
| Chemical oceanography | |
| Oxygen | Quantity: number of profiles = 15 Description: Trace Metal CTD casts |
| Other dissolved gases | Quantity: number of profiles = 15 Description: Trace Metal CTD casts |
| Phosphate | Quantity: number of profiles = 15 Description: Trace Metal CTD casts |
| Nitrate | Quantity: number of profiles = 15 Description: Trace Metal CTD casts |
| Ammonia | Quantity: number of deployments = 100 Description: Marine Snow Catchers. Over 100 deployments |
| Silicate | Quantity: number of profiles = 15 Description: Stainless Steel CTD Casts |
| Alkalinity | Quantity: number of profiles = 15 Description: Stainless Steel CTD Casts |
| Other chemical oceanographic measurements | Quantity: number of profiles = 15 Description: Stainless Steel CTD Casts |
| Contamination | |
| Suspended matter | Quantity: number of deployments = 15 Description: Stand Alone Pumping Systems |
| Suspended matter | Quantity: number of deployments = 100 Description: Marine Snow Catchers. Over 100 deployments |
| Biology and fisheries | |
| Primary productivity | Quantity: number of profiles = 15 Description: Stainless Steel CTD Casts |
| Phytoplankton pigs (eg chlorophyll, fluorescence) | Quantity: number of profiles = 15 Description: Stainless Steel CTD Casts |
| Particulate organic matter (inc POC, PON) | Quantity: number of deployments = 100 Description: Marine Snow Catchers. Over 100 deployments |
| Particulate organic matter (inc POC, PON) | Quantity: activity duration in days = 60 Description: Gliders |
| Particulate organic matter (inc POC, PON) | Quantity: number of profiles = 15 Description: Stainless Steel CTD Casts |
| Dissolved organic matter (inc DOC) | Quantity: number of profiles = 15 Description: Stainless Steel CTD Casts |
| Dissolved organic matter (inc DOC) | Quantity: activity duration in days = 60 Description: Gliders |
| Zooplankton | Quantity: number of deployments = 25 Description: Bongo Net |
| Zooplankton | Quantity: number of deployments = 6 Description: MOCNESS Net |
| Zooplankton | Quantity: number of deployments = 6 Description: Mammoth Net |
| Zooplankton | Quantity: number of profiles = 15 Description: Stainless Steel CTD Casts |
| Nekton | Quantity: number of deployments = 8 Description: RMT 25 NET |
| Moorings, landers, buoys | |
| Physical oceanography | |
| CTD stations | 52° 42' 17" S 40° 6' 24" W — 2 Gliders were continuously patrolling the work area, with the deployment period starting approx one month before, ane ending about 1 mo after, the cruise dates. |
| CTD stations | 52° 42' 17" S 40° 6' 24" W — 6 Argo Floats |
| Subsurface temperature and salinity measurements | 52° 42' 0" S 40° 6' 24" W — 7 Deployments of Drifting neutrally bouyant sediment traps |
| Transparency (eg transmissometer) | 52° 42' 17" S 40° 6' 24" W — 2 Gliders were continuously patrolling the work area, with the deployment period starting approx one month before, ane ending about 1 mo after, the cruise dates. |
| Surface drifters/drifting buoys | 52° 41' 53" S 40° 10' 5" W — 3 Deployments of Drifting array of in situ respirometers |
| Neutrally buoyant floats | 52° 42' 0" S 40° 6' 24" W — 7 Deployments of Drifting neutrally bouyant sediment traps |
| Neutrally buoyant floats | 52° 42' 17" S 40° 6' 24" W — 6 Argo Floats |
| Chemical oceanography | |
| Oxygen | 52° 41' 53" S 40° 10' 5" W — 3 Deployments of Drifting array of in situ respirometers |
| Oxygen | 52° 42' 17" S 40° 6' 24" W — 2 Gliders were continuously patrolling the work area, with the deployment period starting approx one month before, ane ending about 1 mo after, the cruise dates. |
| Oxygen | 52° 42' 17" S 40° 6' 24" W — 6 Argo Floats |
| pH | 52° 42' 17" S 40° 6' 24" W — 6 Argo Floats |
| Biology and fisheries | |
| Phytoplankton pigs (eg chlorophyll, fluorescence) | 52° 42' 17" S 40° 6' 24" W — 2 Gliders were continuously patrolling the work area, with the deployment period starting approx one month before, ane ending about 1 mo after, the cruise dates. |
| Particulate organic matter (inc POC, PON) | 52° 41' 53" S 40° 10' 5" W — 3 Deployments of Drifting array of in situ respirometers |
| Particulate organic matter (inc POC, PON) | 52° 42' 0" S 40° 6' 24" W — 7 Deployments of Drifting neutrally bouyant sediment traps |
| Particulate organic matter (inc POC, PON) | 52° 42' 17" S 40° 6' 24" W — 2 Gliders were continuously patrolling the work area, with the deployment period starting approx one month before, ane ending about 1 mo after, the cruise dates. |
| Biochemical measurements (eg lipids, amino acids) | 52° 42' 0" S 40° 6' 24" W — 7 Deployments of Drifting neutrally bouyant sediment traps |
| Sediment traps | 52° 42' 0" S 40° 6' 24" W — 7 Deployments of Drifting neutrally bouyant sediment traps |
| Sediment traps | 52° 41' 53" S 40° 10' 5" W — 3 Deployments of Drifting array of in situ respirometers |
| Data held at BODC | Get data |
| Discrete samples | |
| 3 Autonomous Underwater Vehicle deployment | |
| 25 CTD frame plus rosette sampler | |
| 42 Drifting rig with sediment traps | |
| 126 Marine snow catcher | |
| 26 Optical instruments | |
| 7 RMT multiple zooplankton net tow | |
| 5 Stand-alone pumps | |
| 31 Twin WP-2 net mounted on a frame | |
| 15 Unspecified zooplankton net or nets | |
| 8 |