Cruise inventory

RRS Discovery D175

Cruise summary report

Cruise Info. 
Ship name (ship code)RRS Discovery (74E3)
Cruise identifierD175
Cruise period1988-06-18 — 1988-07-15
Port of departureBarry, United Kingdom
Port of returnLisbon, Portugal
Objectives1. To recover sediment trap and Bathysnap moorings previously laid in the Porcupine Seabight.
2. To attempt to recover an amphipod trap at the EEC site.
3. To carry out biological, chemical and physical investigations at the BIOTRANS site to study the flux of particles throughout the water column. These investigations are to include:
(a) Sediment trap moorings to assess the sedimentation rate of particles, and to provide material for biological and chemical analyses.
(b) In situ particle counting to profile particles size distribution throughout the water column. This should enable the assessment of mass particle concentration.
(c) Large volume filtration systems to provide material for chemical analyses.
(d) Net collection of plankton and micronekton to assess their vertical distribution, diel migrations, and role in trophic transformations and vertical transport of particulate carbon.
(e) Collection of surface sediments for biological and chemical analyses.
(f) Assessment of phytoplankton and bacterial biomass in the euphotic zone, with measurements of flagellate grazing potential.
Chief scientistPhil Pugh (Institute of Oceanographic Sciences Wormley Laboratory)
Cruise reportRRS Discovery D175 cruise report d175.pdf — access key 'C' (1.42 MB) 
Ocean/sea areas 
GeneralNorth East Atlantic Ocean (limit 40W)
SpecificBIOTRANS site 47deg00-47deg30N, 19deg-20degW
Track chartsRRS Discovery D175 cruise track — d175track.pdf (0.02 MB) 
Physical oceanography 
Surface measurements underway (T,S)Description: T only
BathythermographQuantity: number of profiles = 44
CTD stationsQuantity: number of stations = 16
Description: light meter,transmissometer,underwater fluorometer & oxygen
Optics (eg underwater light levels)Quantity: number of stations = 16
Description: light meter,transmissometer,underwater fluorometer & oxygen
Current profiler (eg ADCP)Description: ADCP for deep scattering layer
Surface drifters/drifting buoysQuantity: number of deployments = 6
Description: free floating sediment traps(20,50 & 230m depth)
Chemical oceanography 
OxygenQuantity: number of stations = 16
Description: light meter,transmissometer,underwater fluorometer & oxygen
NitrateQuantity: number of samples = 70
SilicateQuantity: number of samples = 70
Suspended matterQuantity: number of samples = 83
Description: suspended particulate matter in filtration device
Biology and fisheries 
Primary productivity
Phytoplankton pigs (eg chlorophyll, fluorescence)
Phytoplankton pigs (eg chlorophyll, fluorescence)Quantity: number of stations = 16
Description: light meter,transmissometer,underwater fluorometer & oxygen
Particulate organic matter (inc POC, PON)
Biochemical measurements (eg lipids, amino acids)
SestonQuantity: number of samples = 9
Description: 2 moored sediment traps recovered
Pelagic bacteria/micro-organisms
Benthic bacteria/micro-organismsQuantity: number of cores = 2
Pelagic fishDescription: survey:taxonomy,biomass determination,distribution
Acoustic reflection on marine organisms.
Other biological/fisheries measurementDescription: deep scattering layers
Other biological/fisheries measurementDescription: bioluminescence
Geology and geophysics 
Core - soft bottomQuantity: number of cores = 2
Bottom photographyQuantity: number of images = 240
Description: 2 bathysnaps,1 relaid