Adenosine 5'-Triphosphate

Sampling Procedure

The amount of living microbial biomass in the water column was determined by the measurement of adenosine 5'-triphosphate (ATP) concentrations. Seawater samples were filtered through glass fiber filters (Whatman GF/F, 47 mm diameter) to collect particulate material and the filters placed in boiling Tris-buffer for ATP extraction. ATP concentrations were measured on a Turner Luminometer using the firefly bioluminescence technique described by Karl and Holm-Hansen (1978).

The average field precision of Particulate ATP determinations during 2024 determined from triplicate analyses are presented in the Table below. The figure below shows the time-series of our in-house check standard. Should the mean result of the calculated check standard value fall outside the control limits, a new dilution curve will be made and the check standard remeasured against the new curve.

Values obtained using an in-house check standard at 5 ng ATP/ml. The check standard is used to verify the independently made standard curve dilution series used in each analytical run. The mean (± stdev, n=148) was 4.850 ± 0.239 ng ml-1.

Results

The concentration of particulate ATP resembles those of the particulate bioelements, showing maximum concentration near the surface and a decreasing profile with depth (Figure 53). Surface ocean ATP varies between years more than three-fold, with conspicuously high levels noted in 1994-1995.