MEASUREMENT OF PRIMARY PRODUCTION IN AN ENCLOSED WATER COLUMN

A CEE (2.5 m by 16 m) has been used to study the budget of organic production by measuring the changes in POC/N, oxygen and ¹⁴CO₂ uptake through three-week period. ¹⁴C primary production measurements were conducted with 4-hours and 24-hours incubation periods, and with size fractionation. Different types and sizes of bottle effects were examined. Results showed that the oxygen method production was highest, followed by the ¹⁴CO₂ uptake method, and POC gain showed the lowest. The value of PQ should be more than 1.7. The ratio of 4-hour incubation to 24-hour incubation was 2.42±0.22, indicating that net daily production is equal to 9.7±0.9 h of illuminated growth. Different types and sizes of bottles had little effect on primary production.