Aquatic Sciences Meeting, Albuquerque 2001

CS15 Harmful Algal Blooms

Date: Tuesday, February 13, 2001, Time: 2:30:00 PM

Location: Cochiti/Taos

Pustizzi, F, M, University of Delaware, Lewes, USA, franp@udel.edu

Hutchins, D, A, University of Delaware, Lewes, USA, dahutch@udel.edu

EFFECTS OF VARIOUS NITROGEN SOURCES AND LIGHT LEVELS ON THE GROWTH OF THE BROWN TIDE ORGANISM AUREOCOCCUS ANOPHAGEFFERENS IN SEMI-CONTINUOUS AND BATCH CULTURE

Past experiments have suggested that the brown tide organism Aureococcus anophagefferens may have heterotrophic capabilities. Various organic compounds are known to be taken up rapidly and to support growth. It also has been suggested that A. anophagefferens can persist in low light conditions. The specific causes of brown tide blooms are yet undetermined, but it has been suggested that heterotrophy and tolerance of low light levels could contribute to bloom formation and persistence. In this study, A. anophagefferens was grown using semi-continuous and batch culturing techniques and variable N sources (nitrate, ammonium, urea, and glutamic acid) at two light levels. Phosphate was added at Redfield N:P ratios in the medium of experimental cultures ([N]= 50 uM, [P]= 3.125 uM). Attempts are currently being made to isolate A. anophagefferens cultures from Maryland to compare nutrient dynamics with those organisms from New York. Semi-continuous culture methods were found useful for maintaining constant growth rates in A. anophagefferens cultures. Nutrient concentrations, cell counts, and in-vivo chlorophyll concentrations were determined daily in each experiment to examine growth and nutrient uptake between treatments.

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Aquatic Sciences Meeting, Albuquerque 2001

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