Pelagic production in the Gulf of Papua, 2004

A total of 17 stations were occupied opportunistically during the day between 8 and 26 May 2004 for production/respiration experiments. Station notation comprises a station series number followed by the water depth at that station. Repeat visits at 2 stations are indicated by the addition of an 'a' to the station number.Nineteen physical, chemical and biological parameters were derived from direct water samples, CTD data, and the proportion of surface light at which the samples were taken (units of measurement in brackets):Chlorophyll a (µg L-1); Density (Sigma-t ); Fluorescence (mg m-3); Light (Iz, Proportion); Oxygen (O2, mg L-1); Particulate carbon (PC, µg CL-1); Particulate nitrogen (PN, µg NL-1); Total suspended solids (TSS, mg DWL-1); Transmittance (%). Ammonium (NH4+); Dissolved organic carbon (DOC); Dissolved organic nitrogen (DON); Dissolved organic phosphorus (DOP); Nitrite (NO2) ; Nitrite and nitrate (NO2+NO3); Phosphate (PO34); Silica (Si); Total dissolved nitrogen (TDN); Total dissolved phosphorus (TDP), were all measured in µmol L-1.Water samples taken at 19 stations were allocated to groups on the basis of these physico-chemical characteristics.Net community production (NCP) and community respiration (CR) were estimated as the change in oxygen concentration during a 24 h period in iodine flasks incubated in the light and dark respectively. Oxygen flux data was converted to carbon units. Gross primary production (GPP) was calculated as the sum of NCP and CR, and the P:R ratio calculated as the ratio GPP:CR. To experimentally measure oxygen flux to resolve the balance of pelagic production and respiration in the Gulf of Papua. Sampling stations: GH-14, GH-14a, GH-25, GH-35, GH-75, GX-59, GX-71, GX-73, GX-98, GX-2K, T5-51, T8-18, T8-18a, T10-17, T10-26, T10-60, T12-17, T12-35, T13-38.GX-2K depth went to >2000 m.