Nitrogen-stimulated growth of algae in surface-water samples collected from freshwater kettle ponds of Cape Cod National Seashore (Massachusetts, USA)

Abstract

Nutrient enrichment bioassays, coinciding with analyses of surface water nutrients, nitrogen (N) and phosphorus (P), were conducted using water samples collected from 10 freshwater lakes (kettle ponds) of Cape Cod National Seashore (CCNS) (Massachusetts, USA). Algal biomass developing in each treatment was assessed by quantifying chlorophyll a. In July and August, strong responses of a unicellular green alga, Chlamydomonas sp., to N þ P and N enrichments were observed in all water samples, while P alone (or control treatments) had virtually no stimulatory effect. The results indicate that N inputs to these waterbodies can fuel the growth of certain species and should therefore be considered a management priority for CCNS.