Cruise inventory

RRS James Clark Ross JR20030105 (JR82)

Cruise summary report

Cruise Info. 
Ship name (ship code)RRS James Clark Ross (74JC)
Cruise identifierJR20030105 (JR82)
Cruise period2003-01-05 — 2003-02-24
StatusCompleted
Port of departureStanley, Falkland Islands (Malvinas)
Port of returnStanley, Falkland Islands (Malvinas)
PurposeResearch
ObjectivesFrontal Cruise CP8 - Bio Synoptic
JR82 forms part of DYNAMOE (BAS's programme focusing on Antarctic krill within the South Georgia-Scotia Sea ecosystem), to help understand the large scale distribution of Antarctic krill and transport of material within the Scotia Sea. It also forms part ot the UK GLOBEC programme as a component to SO-GLOBEC, to understand the physical-biological factors dictating the distribution, survival, and population size of krill.

This cruise aimed to investigate large-scale transport, growth and survival of krill across the Scotia Sea. The cruise was planned around several principles. Firstly, sea ice is hard to sample properly at large scales, so the cruise was planned for summer when it had retreated furthest. Secondly, the study links well with other studied areas, the Antarctic Peninsula and South Georgia. Thirdly, in the Scotia Sea, the currents do not flow parallel to the winter ice zone but loop far to the north and there is uncertainty over the relative roles of oceanfronts and zones of retreated ice in the generation and transport of krill blooms and aggregations.

Aims:
1. What controls the growth, development and survival of krill in the Scotia Sea?
2. How important are theses processes in determining the distibution and abundance of krill?
3. To sample the Western Core Box as part of an ongoing monitoring programme.
4. To lift and check two moorings as part of an AFI grant.

Results:
1. 8 long transects across Scotia Sea from north of the SACCF to 63° S and east to the South Sandwich Islands, total of 4300 miles.
2. 56 "rapid stations" comprising a period of acoustic searching and target fishing for krill with the RMT. 0-200m CTD drops with water samples analysed at fixed depths. Shallow CTD for particulate filtration and primary production deck incubations. Bongo nets to 400m for mesozooplankton abundance and copepods for condition factor analysis and egg production rate. Sonobuoys for cetacean acoustis deployed in the vicinity of the stations. At 11 stations a pair of Argo drifters drogued at 20 and 100m deployed to measure current velocity in the Eastern Scotia Sea. Series of 6 LHPR hauls to 100m.
3. A series of 24-hour process stations with a high abundance of krill larvae for diel vertical migration cycles was prevented due to a rarity of krill where expected.
Chief scientistAngus Atkinson (British Antarctic Survey)
ProjectDYNAMOE
Coordinating bodyBritish Antarctic Survey (BAS)
Cruise reportRRS James Clark Ross JR20030105 (JR82) cruise report jr82.pdf — access key 'C' (3.47 MB) 
Ocean/sea areas 
GeneralSouth Atlantic Ocean
SpecificScotia Sea, Peninsula to South Georgia
Track chartsRRS James Clark Ross JR20030105 (JR82) cruise track — jr82trk.pdf (00 MB) 
Measurements 
Physical oceanography 
Surface measurements underway (T,S)Quantity: track kilometres = 6919
Description: 8 transects
BathythermographQuantity: track kilometres = 6919
Description: 8 transects
Water bottle stationsQuantity: number of stations = 56
Description: 0-200m with water samples analysed at fixed depths
CTD stationsQuantity: number of stations = 56
Description: 0-200m with water samples analysed at fixed depths
CTD stationsDescription: shallow CTDs
Subsurface temperature and salinity measurementsQuantity: track kilometres = 6919
Description: 8 transects
Surface drifters/drifting buoysQuantity: number of stations = 11
Description: pair of Argo drifters deployed at each station
Biology and fisheries 
Primary productivityDescription: shallow CTDs
Particulate organic matter (inc POC, PON)Description: shallow CTDs
ZooplanktonQuantity: number of stations = 56
Description: Bongo nets to 400m for mesozooplankton and eggs
ZooplanktonQuantity: number of hauls = 6
Description: LHPR to 100m
Eggs and larvaeQuantity: number of stations = 56
Description: Bongo nets to 400m for mesozooplankton and eggs
Mammals and reptilesQuantity: track kilometres = 6919
Description: 8 transects
Acoustic reflection on marine organisms.Quantity: number of stations = 56
Description: Sonobuoys for cetacean acoustics
Acoustic reflection on marine organisms.Quantity: number of stations = 56
Description: acoustic searching for krill
Exploratory fishingQuantity: number of stations = 56
Description: target fishing for krill with a RMT
Data held at BODC 
Discrete samples 
61  CTD frame plus rosette samplerAmmonium and ammonia concentration parameters in water bodies
Silicate concentration parameters in the water column
Nitrate concentration parameters in the water column
Nitrite concentration parameters in the water column
Phosphate concentration parameters in the water column