Date of Award

Summer 1976

Document Type


Degree Name

Master of Science (MS)


Biological Sciences



Committee Director

Harold G. Marshall

Committee Member

Kneeland Nesius

Committee Member

Frank P. Day, Jr.

Call Number for Print

Special Collections LD4331.B46 W43


Phytoplankton samples were collected biweekly from two stations, one in each branch of Lynnhaven Bay, Virginia over the period January 24 to June 9, 1975. Water temperature, salinity, pH, oxygen, ammonia, urea, reactive nitrite, reactive nitrate, reactive phosphorus, productivity, transparency, and weather conditions were recorded concurrently. Data were manipulated employing analysis of variance, simple correlation, correlation matrices, and forward stepwise multiple regression. Total phytoplankton numbers exhibited a unimodal pattern. A pre-bloom pulse was recorded at both stations in late February. The spring bloom lasted from April through May. Phytoplankton growth was primarily a function of nutrient supply and temperature. Nutrient run-off following heavy spring rains appeared to stimulate pyrrhophycean growth. Changes in species composition and dominant phytoplankters occurred following these perturbations. Productivity exhibited a distinctive bimodal pattern, increasing in

late February and again from late March through early May. Productivity was primarily a function of light and temperature. Nannoplankters, particularly cryptophytes, cyanophytes, and xanthophytes were very important throughout this study. Olisthodiscus sp. and Rhodomonas amphioxeia were dominant from January through March. S. costatum became dominant in April and remained so until dominance shifted to an unidentified phytoflagellate in late May. Both stations were similar in species composition and succession. Total phytoplankton counts were generally higher at Station II in the Eastern Branch, reaching 3.8 x 107 numbers 1-l on May 22.


In Copyright. URI: This Item is protected by copyright and/or related rights. You are free to use this Item in any way that is permitted by the copyright and related rights legislation that applies to your use. For other uses you need to obtain permission from the rights-holder(s).