Primary Production

C. Knudson, W.S. Chamberlin, J. Marra
Lamont-Doherty Geological Observatory

Primary production measurements were made using the 14C technique. Water samples were collected before dawn each day from acid-cleaned 20 and 30 liter Go-Flo sampling bottles. Each sample was inoculated with 9.0 uCi sterile NaH14CO3 solution and incubated in 265 ml polystyrene tissue culture flasks. New sterile flasks were used for each sample and a teflon liner was placed in the cap of each flask prior to incubation. There were four replicates at each depth. Dawn to dusk incubations were carried out in situ (except for 28 April when we performed a 4 h experiment about local noon). The two replicates that were incubated for 24 h were stored in an on deck surface water-cooled incubator from dusk to the following dawn. After the incubation period the samples were filtered onto Millipore HA filters. The filters were then soaked in a few drops of 10% HCl in scintillation vials. After 3-4 h, fluor was added, and the samples were counted on the ship's Beckman LS 100 scintillation counter. A subsequent count was conducted at L-DGO.

The data shows the average of the two replicates for the dawn-to- dusk (14 h) (or, in the case of 28 April, the 4 h experiment) and dawn-to-dawn incubations. The variation about these replicates is less than 15%.