The Upper Limit of Phytoplankton Production as a Function of Nutrient Load, Temperature, Retention Time of the Water, and Euphotic Zone Depth
✍ Scribed by Prof. Dr. Dietrich Uhlmann
- Publisher
- John Wiley and Sons
- Year
- 1978
- Tongue
- English
- Weight
- 677 KB
- Volume
- 63
- Category
- Article
- ISSN
- 1434-2944
No coin nor oath required. For personal study only.
✦ Synopsis
I n laboratory models of sewage ponds operated on a semicontinuous-flow basis, the net primary production l i ' of the phytoplankton was measured by harvesting the suspended matter both from the outflow and the bottom of the vessels a t daily intervals. The maximum value of Il was as high as 50 mg dry weight/l * day (corresponding to 20 mg C/1 day). With the nutrient load L kept ad a constant level, the steady state phytoplankton biomass z decreased with decreasing water residence time t in accordance with the dropping inflow concentration of the nutrients. On the other hand, a t 20 *C no higher Z was yielded at t=40 than a t t = 5 days. This result obviously has to be attributed to a substantial increase in grazing rate with progressing t a t the temperature level of 20 and 30 O C . I n this connection extremely low magnitudes of Il may result despite optimum levels of nutrient supply, radiation and temperature. The highest estimates of Il hitherto measured and recorded in the literature relate to the euphotic zone depth (zeu in m) as follows: n[gC/m* * d] S 8,3 * .zeu10,47