RV Pelagia PE246 (RANAMOX)

Cruise summary report

Cruise Info. 
Ship name (ship code)RV Pelagia (64PE)
Cruise identifierPE246 (RANAMOX)
Cruise period2006-03-13 — 2006-04-04
Port of departureHet Horntje, Netherlands
Port of returnHet Horntje, Netherlands
ObjectivesThe cruise aimed to continue the work started on the first two cruises in this project that took place in spring and autumn of last year.

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, oxygen uptake rates, oxygen and nutrient profiles. Samples were taken for the determination of C and N, molecular analysis, as well as sediment porosity.
Chief scientistJoanna C Nicholls (Queen Mary University of London School of Biological and Chemical Sciences)
ProjectRegulation of anaerobic ammonium oxidation in estuarine and continental shelf se
Coordinating bodyQueen Mary University of London School of Biological and
Ocean/sea areas 
GeneralIrish Sea and St. George's Channel
North East Atlantic Ocean (limit 40W)
SpecificThe Shelf break, North Atlantic, south of the South Western Approaches, 145 Irish Sea, 181 Six sites 1; -9.85307, 48.06218, 2; -9.70602, 48.17887, 3; -9.70922, 48.2669, 4; -6.09968, 51.21805, 5; -5.59223, 53.882, 6; -5.58365, 54.11903.
Track chartsRV Pelagia PE246 (RANAMOX) cruise track — pe246roscop4836trk.pdf (0.07 MB) 
Physical oceanography 
CTD stationsQuantity: number of profiles = 10
Description: CTD drop for vertical profile (up and down casts) ; salinity, temperature, depth, turbidity, PAR and oxygen. Discrete sampling at every m. Bottom water concentrations of NO3-, NO2- and NH4+ were measured using colourmetric 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 bottomQuantity: number of samples = 24
Description: Repeated box cores over 6 stations for sub-sampling into cores. The cores were then used to measure oxygen uptake, oxygen profiles, nutrient profiles, potential denitrification and anammox rates. Sub samples of the cores were taken for molecular analysis.