RRS James Clark Ross JR19980114 (JR28)

Cruise summary report

Cruise Info. 
Ship name (ship code)RRS James Clark Ross (74JC)
Cruise identifierJR19980114 (JR28)
Cruise period1998-01-14 — 1998-02-07
Port of departureStanley, Falkland Islands (Malvinas)
Port of returnStanley, Falkland Islands (Malvinas)
ObjectivesThe Pelagic Ecosystem Studies Core Programme is aimed understanding the processes generating variability in the South Georgia marine ecosystem, with a particular emphasis on the interannual variation. JR28 was the third execution of the programme.

The ship steamed to the head of a standard oceanographic transect just to the north of the Maurice Ewing Bank (MEB). The transect consisted of 22 hydrographic stations, 35km apart. On each station a CTD profile with water bottle samples was taken to generate profiles of standard physical characters and allow chemical analyses and the determination of chlorophyll concentration. There was also simultaneous squid jigging undertaken. Zooplankton net hauls were used to characterise the zooplankton community on each station and a chlorophyll fluorescence profile was also obtained using an Aquapack system. On a number of stations extra water and zooplankton samples were obtained for detailed biochemical analyses. In the vicinity of South Georgia surveys of two mesoscale (80 x 80km) boxes consisting of 5 sets of paired transects were conducted. A towed undulating oceanographic recorder (UOR) was used to characterise the upper150 m water characteristics and a multifrequency acoustic system was used to describe the distribution of krill and other acoustic scatterers. Underway chemistry and standard analyses of the surface water were also undertaken. A series of standard station activities of CTD, water bottle samples, RMT8 and zooplankton net hauls were carried out at on-shelf and off-shelf stations within each survey area. Transecting was also undertaken to characterise the region of the north shelf not included in the survey boxes. Experimental work on zooplankton grazing, excretion and development rates was also undertaken. Most of the data were validated and calibrated at sea and are available for comparative analyses with data from the previous two seasons. The preliminary figures indicate that there are some significant differences from earlier surveys in both the physical and biological regimes.
Chief scientistJulian Priddle (British Antarctic Survey)
ProjectPES Core Programme II
Coordinating bodyBritish Antarctic Survey (BAS)
Cruise reportRRS James Clark Ross JR19980114 (JR28) cruise report jr028.pdf (0.72 MB) 
Ocean/sea areas 
GeneralSouth Atlantic Ocean
SpecificSouthern Ocean
Data held at BODC 
Discrete samples 
94  Sample taken from ship's non-toxic supply