RV Lough Foyle LFjul92
Cruise summary report
| Cruise Info. | |
| Ship name (ship code) | RV Lough Foyle (74LG) |
| Cruise identifier | LFjul92 |
| Cruise period | 1992-07-13 — 1992-07-16 |
| Status | Completed |
| Port of departure | Belfast, United Kingdom |
| Port of return | Belfast, United Kingdom |
| Purpose | Research |
| Objectives | 1) To investigate the distribution of dissolved inorganic nutrients and phytoplankton biomass in relation to the vertical structure of the water column.
2) To estimate phytoplankton production at selected locations and carry out a comparison between in situ and ship-board, incubator estimates of primary production. Water samples were collected from depths selected on the basis of the vertical distribution of temperature and salinity for estimation of phytoplankton chlorophyll and dissolved inorganic nutrients. Water samples were preserved with acidic Lugol's iodine for microscopic analysis of phytoplankton species composition and abundance. The spatial distribution of physical, chemical and biological variables in near surface water were mapped continuously when the ship was steaming between stations. |
| Chief scientist | Richard Gowen (Department of Agriculture for Northern Ireland) |
| Cruise report |  (0.12 MB) |
| Ocean/sea areas | |
| General | Irish Sea and St. George's Channel |
| Specific | The Irish Sea |
| Measurements | |
| Physical oceanography | |
| CTD stations | Quantity: number of stations = 26 Description: Vertical profiles of temperature and conductivity measured with the Hydrobios CTD and Chelsea Instruments fluorometer |
| Transparency (eg transmissometer) | Quantity: number of stations = 26 Description: Secchi disc used |
| Optics (eg underwater light levels) | Quantity: number of stations = 7 Description: At selected stations, downwelling and upwelling irradiance was measured using Licor 2 Phi sensors. At these stations, water samples were collected and used to estimate carbon fixation by phytoplankton using a standard C-14 technique |
| Chemical oceanography | |
| Oxygen | Quantity: number of stations = 2 Description: Samples of near bottom water were collected from seleced stations for the estimation of dissolved oxygen |
| Biology and fisheries | |
| Primary productivity | Quantity: number of stations = 9 Description: Productivity experiments carried out |
| Phytoplankton pigs (eg chlorophyll, fluorescence) | Quantity: number of stations = 26 Description: Vertical profiles of fluorescence measured with the Hydrobios CTD and Chelsea Instruments fluorometer |
| Zooplankton | Quantity: number of stations = 26 Description: 2 vertical zooplankton hauls were made at each station using one of the Bongo nets fitted with a 300 micrometer mesh net. One sample was preserved with formalin for later analysis and the second sample was filtered |
