HETEROTROPHIC ACTIVITY, GLUCOSE-UPTAKE AND PRIMARY PRODUCTIVITY IN LAKE KINNERET

SUMMARY. Chlorophyll, ATP and glucose concentrations as well as glucose uptake rate and primary production were determined every 2–4 h during three 24–h surveys in Lake Kinneret. In spite of the fluctuations in glucose uptake rate, the estimation of the daily glucose uptake rate from a single sampling carried out at 10.00 hours is justified. The same applies also for the primary production. Routine bi‐weekly determinations of primary production and glucose uptake rate were carried out from October 1976 to July 1977. No correlations were found between glucose uptake rates and ambient concentrations of ATP, chlorophyll and glucose. The glucose uptake rate showed two distinct seasonal patterns; the period which was dominated by the Peridinium (January‐April) and the rest of the year. In the former period the percentage of glucose‐carbon utilized out of the carbon formed in the water column by the photosynthetic activity, fluctuated between 1 and 9%, and in the latter period fluctuated between 5 and 37%. The yearly average was 11.1%, SD 9.8. Copyright © 1979, Wiley Blackwell. All rights reserved