Published:
January 1, 1998
Originator:
VIMS

Nutrient-addition bioassays were conducted periodically in the James, York and Rappahannock Rivera and the mainstem, lower Chesapeake Bay from 1985 through early 1993 for the purpose of describing temporal and spatial patterns of nutrient limitation of phytoplankton growth and abundance in these tidally-incluenced aquatic systems. All studies involved the addition off nitrogen (N), phosphorus (P) and silica (Si), either singly or in combination, to contained, natural water samples and, after some period of growth (days), a comparison of the response of the phytoplankton in the nutrient-enriched treatments to those without added nutrients (i.e., controls). The magnitude of the respnse of the phytoplankton community (as measured by chlorophyll) to an added nutrient is proportional to the degree of limitation imposed by that nutrient in the natural environment. Nutrient response indices were determined for each treatment for the day of maximum response of the phytoplankton community.

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