Determination of growth-limiting nutrients for red species ofOscillatoriaand two ‘oligotrophic’ diatoms
✍ Scribed by Øivind Løvstad
- Publisher
- Springer
- Year
- 1983
- Tongue
- English
- Weight
- 612 KB
- Volume
- 107
- Category
- Article
- ISSN
- 1573-5141
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✦ Synopsis
Laboratory batch experiments with dilute phytoplankton communities were carried out to determine growth-limiting nutrients and the degree of growth limitation for Asterionella formosa, Hass ., Tabellaria fenestrata (Lyngb .) Kiitz . and red species of Oscillatoria under specific temperature and light conditions .
Water samples from five Norwegian lakes with average epilimnetic total phosphorus concentrations ranging from 5 to 30 .tg P per 1 were investigated . Both enrichment and transplant experiments were carried out .
In samples from the most oligotrophic lakes (Lake Randsfjorden and Lake Tyrifjorden) phosphorus was found to be the growth-limiting nutrient . In samples from Lake Mjesa silicate was also growth-limiting for the diatoms, while nitrogen could be limiting for both Asterionella and Oscillatoria from Lake Steinsfjorden . Phosphorus was often the only limiting nutrient determined for Oscillatoria in Lake Gjersjeen (the most eutrophic of the lakes) . In samples from this lake, however, Asterionella was also growth-limited directly or indirectly as a result of high pH (pH > 9) . This was also found for Asterionella and Tabellaria from lake Mjesa by means of transplant experiments . Oscillatoria from Lake Gjersjeen could not grow in filtered water from Lake Mjesa but obtained maximum growth rate after addition of phosphate and chelated iron in combination .