RRS Discovery D175
Cruise summary report
| Cruise Info. | |
| Ship name (ship code) | RRS Discovery (74E3) |
| Cruise identifier | D175 |
| Cruise period | 1988-06-18 — 1988-07-15 |
| Status | Completed |
| Port of departure | Barry, United Kingdom |
| Port of return | Lisbon, Portugal |
| Purpose | Research |
| Objectives | 1. 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 scientist | Phil Pugh (Institute of Oceanographic Sciences Wormley Laboratory) |
| Cruise report |  (1.42 MB) |
| Ocean/sea areas | |
| General | North East Atlantic Ocean (limit 40W) |
| Specific | BIOTRANS site 47deg00-47deg30N, 19deg-20degW |
| Track charts | (0.02 MB) |
| Measurements | |
| Physical oceanography | |
| Surface measurements underway (T,S) | Description: T only |
| Bathythermograph | Quantity: number of profiles = 44 |
| CTD stations | Quantity: 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 buoys | Quantity: number of deployments = 6 Description: free floating sediment traps(20,50 & 230m depth) |
| Chemical oceanography | |
| Oxygen | Quantity: number of stations = 16 Description: light meter,transmissometer,underwater fluorometer & oxygen |
| Nitrate | Quantity: number of samples = 70 |
| Silicate | Quantity: number of samples = 70 |
| Contamination | |
| Suspended matter | Quantity: 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) | |
| Phytoplankton | |
| Zooplankton | |
| Seston | Quantity: number of samples = 9 Description: 2 moored sediment traps recovered |
| Nekton | |
| Pelagic bacteria/micro-organisms | |
| Benthic bacteria/micro-organisms | Quantity: number of cores = 2 |
| Pelagic fish | Description: survey:taxonomy,biomass determination,distribution |
| Acoustic reflection on marine organisms. | |
| Other biological/fisheries measurement | Description: bioluminescence |
| Other biological/fisheries measurement | Description: deep scattering layers |
| Geology and geophysics | |
| Core - soft bottom | Quantity: number of cores = 2 |
| Bottom photography | Quantity: number of images = 240 Description: 2 bathysnaps,1 relaid |
