RRS Charles Darwin CD175
Cruise summary report
| Cruise Info. | |
| Ship name (ship code) | RRS Charles Darwin (74AB) |
| Cruise identifier | CD175 |
| Cruise period | 2005-09-12 — 2005-10-02 |
| Status | Completed |
| Port of departure | Fairlie, United Kingdom |
| Port of return | Birkenhead, United Kingdom |
| Purpose | Research |
| Objectives | The cruise aimed to continue the work started on the first cruise in this project that took place in spring. We collected samples from a range of soft substrata using a box corer along a depth transect. The purpose of this sampling was to examine differences and possible regulatory factors to the contribution of anammox (anaerobic ammonium oxidation) and denitrification in the coastal sea environment. The work is part of a wider project in which we are studying the regulatory factors and potential contributions of the novel anammox process in estuarine and coastal sediments, and hopefully to put it into context as part of the global nitrogen cycle. Sediments were sampled and incubated in bottom water collected using the CTD before 15N tracer experiments were used to examine the rates and contributions of anammox and denitrification. At the same time data were collected using the CTD array to provide information on the water column above the sediments. We also measured selected nutrient concentrations from the bottom water samples as well as dissolved oxygen and oxygen uptake rates. Samples were taken for the determination of C and N, as well as sediment porosity. |
| Chief scientist | Joanna C Nicholls (Queen Mary University of London School of Biological and Chemical Sciences) |
| Project | Regulation of anaerobic ammonium oxidation in estuarine/continental shelf seds. |
| Coordinating body | School of Biological Sciences, Queen Mary University of London |
| Ocean/sea areas | |
| General | Irish Sea and St. George's Channel Celtic Sea North East Atlantic Ocean (limit 40W) |
| Specific | The Shelf break, North Atlantic, south of the South Western Approaches, Irish Sea |
| Track charts |  (0.17 MB) |
| Measurements | |
| Physical oceanography | |
| Water bottle stations | Quantity: number of profiles = 6 Description: CTD drop for vertical profile (up and down casts) ; salinity, temperature, depth, turbidity, PAR and oxygen. Bottle rosette. NO3-, NO2- and NH4+ were measured using colorimetric detection methods (Kirkwood, 1996). The samples were primarily taken as a water bath for incubating cores under in situ water. |
| CTD stations | Quantity: number of profiles = 6 Description: CTD drop for vertical profile (up and down casts) ; salinity, temperature, depth, turbidity, PAR and oxygen. Bottle rosette. NO3-, NO2- and NH4+ were measured using colorimetric detection methods (Kirkwood, 1996). The samples were primarily taken as a water bath for incubating cores under in situ water. |
| Chemical oceanography | |
| Nitrate | Quantity: number of profiles = 6 Description: CTD drop for vertical profile (up and down casts) ; salinity, temperature, depth, turbidity, PAR and oxygen. Bottle rosette. NO3-, NO2- and NH4+ were measured using colorimetric detection methods (Kirkwood, 1996). The samples were primarily taken as a water bath for incubating cores under in situ water. |
| Nitrite | Quantity: number of profiles = 6 Description: CTD drop for vertical profile (up and down casts) ; salinity, temperature, depth, turbidity, PAR and oxygen. Bottle rosette. NO3-, NO2- and NH4+ were measured using colorimetric detection methods (Kirkwood, 1996). The samples were primarily taken as a water bath for incubating cores under in situ water. |
| Ammonia | Quantity: number of profiles = 6 Description: CTD drop for vertical profile (up and down casts) ; salinity, temperature, depth, turbidity, PAR and oxygen. Bottle rosette. NO3-, NO2- and NH4+ were measured using colorimetric detection methods (Kirkwood, 1996). The samples were primarily taken as a water bath for incubating cores under in situ water. |
| Geology and geophysics | |
| Core - soft bottom | Quantity: number of deployments = 20 Description: SMBA box corer. Repeated box cores over 6 stations for sub-sampling into cores. The cores were then used to measure oxygen uptake, potential denitrification and anammox rates. |
