Concentration of substances sediment - per unit volume of whole sediment or sediment pore water only?

[roswri]

Parameters include:

• Large Phytoplankton N in Sediment, Large Phytoplankton N sediment (model: 'PhyL_N_sed', sensor: '', standard: ''')
• Small Phytoplankton N in Sediment, Small Phytoplankton N sediment (model: 'PhyS_N_sed', sensor: '', standard: ''')
• Trichodesmium Nitrogen in Sediment, Trichodesmium Nitrogen sediment (model: 'Tricho_N_sed', sensor: '', standard: ''')
• Large Zooplankton N in Sediment, Large Zooplankton N sediment (model: 'ZooL_N_sed', sensor: '', standard: ''')
• Small Zooplankton N in Sediment, Small Zooplankton N sediment (model: 'ZooS_N_sed', sensor: '', standard: ''')
• Carbonate in Sediment, Carbonate sediment (model: 'CO32_sed', sensor: '', standard: ''')
• Bicarbonate in Sediment, Bicarbonate sediment (model: 'HCO3_sed', sensor: '', standard: ''')
• Total Chlorophyll in Sediment, Total Chlorophyll sediment (model: 'Chl_a_sum_sed', sensor: '', standard: ''')
• Dissolved Inorganic Carbon in Sediment, Dissolved Inorganic Carbon sediment (model: 'DIC_sed', sensor: '', standard: ''')
• Dissolved Inorganic Nitrogen in Sediment, Dissolved Inorganic Nitrogen sediment (model: 'DIN_sed', sensor: '', standard: ''')
• Dissolved Inorganic Phosphorus in Sediment, Dissolved Inorganic Phosphorus sediment (model: 'DIP_sed', sensor: '', standard: ''')
• Dissolved Organic Carbon in Sediment, Dissolved Organic Carbon sediment (model: 'DOR_C_sed', sensor: '', standard: ''')
• Dissolved Organic Nitrogen in Sediment, Dissolved Organic Nitrogen sediment (model: 'DOR_N_sed', sensor: '', standard: ''')
• Dissolved Organic Phosphorus in Sediment, Dissolved Organic Phosphorus sediment (model: 'DOR_P_sed', sensor: '', standard: ''')
• Ammonia in Sediment, Ammonia sediment (model: 'NH4_sed', sensor: '', standard: ''')
• Nitrate in Sediment, Nitrate sediment (model: 'NO3_sed', sensor: 'Nitrate', standard: ''')
• Dissolved Oxygen in Sediment, Dissolved Oxygen sediment (model: 'Oxygen_sed', sensor: '', standard: ''')
• Particulate Inorganic Phosphorus in Sediment, Particulate Inorganic Phosphorus sediment (model: 'PIP_sed', sensor: '', standard: ''')
• Total C in Sediment, Total C sediment (model: 'TC_sed', sensor: '', standard: ''')
• Total N in Sediment, Total N sediment (model: 'TN_sed', sensor: '', standard: ''')
• Total P in Sediment, Total P sediment (model: 'TP_sed', sensor: '', standard: ''')

Units: Milligrams per cubic metre

Are the concentrations of these substances described per cubic metre of the sediment as a whole (pore water + physical sediment grains), or per unit volume of the sediment pore water only?

[sharon-tickell]

I'll have to defer to @nugzarm on that one!

[markebaird]

If it is a dissolved substance then it is per unit of volume of porewater. If it is particle (or a sum of a particle and dissolved substances such as TN) then it is per cubic metre of sediment as a whole. Note: All properties of cells (reserves and pigments) are considered particulate.

[roswri]

Hi @markebaird,

I have the same question for the chemical and biochemical oxygen demand parameters in sediment - would this be per unit volume of sediment pore water?

Thanks, Roseanna