The effects of ammonium and phosphate enrichments on clorophylla, pigment ratio and species composition of phytoplankton of Vineyard Sound

✍ Scribed by S. Vince; I. Valiela

• Publisher: Springer-Verlag
• Year: 1973
• Tongue: English
• Weight: 419 KB
• Volume: 19
• Category: Article
• ISSN: 0025-3162
• DOI: 10.1007/bf00355422

✦ Synopsis

Seawater containing natural phytoplankton populations from Vineyard Sound, USA was enriched in the laboratory with three levels each of ammonium and phosphate and with a combination of ammonium and phosphate which provided three different N :P ratios. The addition of ammonium produced more cells and chlorophyll a than the control or the phosphate enrichments. However, enrichment with ammonium and phosphate, regardless of the N:P ratio, yielded the most cells and chlorophyll a. Thus, nitrogen seems to be the primary limiting nutrient, with phosphate showing secondary limiting -D430effects. The ratios of photosynthetic pigments ~ decreased with the increased chlorophyll a production in the enriched cultures. There were no significant changes in the species composition within the cultures, so that the observed changes in pigment ratio and chlorophyll a content were due to physiological responses.