Cruise inventory

RRS Challenger CH17

Cruise summary report

Cruise Info. 
Ship name (ship code)RRS Challenger (74CH)
Cruise identifierCH17
Cruise period1987-07-06 — 1987-08-02
Port of departureTroon, United Kingdom
Port of returnPlymouth, United Kingdom
Objectives1. To measure the concentrations and distribution of major nutrients in the North Sea with particular emphasis on the sea areas bordering the major estuaries.
2. To measure the rates of primary production and nitrogen assimilation of phytoplankton, and their horizontal distribution in relation to nitrogen inputs.
3. To measure the variations in the natural abundance of 15N in particulate and dissolved nitrogen and to relate these to the inputs and internal cycling of nitrogen.
4. To measure sedimentation rates of particular matter at selected sites in the North Sea.
5. To measure the rates of denitrification in the sediments of the North Sea.
6. To characterise the natural phytoplankton populations using shipboard flow cytometry.
7. To determine the distribution and concentrations of dissolved and particulate-bound trace metals with particular emphasis on the regions around estuarine plumes.
8. To measure the concentrations and sizes of natural particulate material using in situ sizing techniques and to compare the results obtained to those from conventional techniques.
9. To determine the numbers of cyanobacteria in the North Sea and to measure their rates of photosynthesis and various physiological/ecological properties.
10. To deploy the IMER offshore mesocosm and to conduct time series experiments of 2-3 days duration in relation to enrichment of the water column by plant nutrients.
11. To investigate, in detail at one site, aspects of denitrification.
12. To conduct investigations on the populations, physiology, size and trophic structure of natural populations of plankton and using shipboard flow cytometry.
Chief scientistNick Owens (Institute of Marine Environmental Research, Plymouth)
Cruise reportRRS Challenger CH17 cruise report ch17_87.pdf — access key 'C' (0.73 MB) 
Ocean/sea areas 
GeneralNorth Sea
SpecificNorth Sea
Track chartsRRS Challenger CH17 cruise track — ch17_87track.pdf (0.04 MB) 
Physical oceanography 
Surface measurements underway (T,S)Quantity: track kilometres = 3557
Water bottle stationsQuantity: number of stations = 35
Description: S surface only
CTD stationsQuantity: number of stations = 74
Subsurface temperature and salinity measurementsQuantity: track kilometres = 3557
Optics (eg underwater light levels)Quantity: track kilometres = 3557.692
Chemical oceanography 
Other dissolved gasesQuantity: track kilometres = 3557
PhosphateQuantity: track kilometres = 4444.8
Description: continuous observations throughout the cruise.
NitrateQuantity: track kilometres = 4444.8
Description: continuous observations throughout the cruise.
NitriteQuantity: track kilometres = 4444.8
Description: continuous observations throughout the cruise.
SilicateQuantity: track kilometres = 4444.8
Description: continuous observations throughout the cruise.
Biology and fisheries 
Primary productivityQuantity: number of experiments = 74
Phytoplankton pigs (eg chlorophyll, fluorescence)Quantity: number of profiles = 74
Particulate organic matter (inc POC, PON)Quantity: number of profiles = 74
PhytoplanktonQuantity: number of profiles = 74
Description: survey distribution, biomass determination and energy transfers.
Geology and geophysics 
Core - soft bottomQuantity: number of cores = 8
Description: chemical analysis