RV Pelagia PE234

Cruise summary report

Cruise Info. 
Ship name (ship code)RV Pelagia (64PE)
Cruise identifierPE234
Cruise period2005-03-24 — 2005-04-14
Port of departureHet Horntje, Netherlands
Port of returnHet Horntje, Netherlands
ObjectivesThe cruise aimed to sample 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 scientistJoanna C Nicholls (Queen Mary University of London School of Biological and Chemical Sciences)
ProjectRegulation of anaerobic ammonium oxidation in estuarine & continental shelf seds
Coordinating bodySchool of Biological Sciences, Queen Mary Univ. of London
Ocean/sea areas 
GeneralNorth Atlantic Ocean
Irish Sea and St. George's Channel
SpecificThe Shelf break, North Atlantic, south of the South Western Approaches, Irish Sea
Track chartsRV Pelagia PE234 cruise track — pe234roscop4747trk_05.pdf (0.08 MB) 
Physical oceanography 
CTD stationsQuantity: number of profiles = 6
Description: CTD drop for vertical profile (up and down casts); salinity, temperature, depth, turbidity. Discrete sampling at every m. The oxygen concentration of the bottom water was measured by Winkler analysis, 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 = 25
Description: 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.