PICOPHYTOPLANKTON SEASONAL CYCLE AT THE SIO PIER, LA JOLLA, CALIFORNIA

• Published in: Journal of phycology Vol. 36; no. s3; p. 53
• Main Author: Palenik, B.P.
• Format: Journal Article
• Language: English
• Published: Boston, MA, USA Blackwell Science Inc 01.12.2000
• Subjects: Cyanophyta; Marine; Prasinophyta; INE, USA, California, La Jolla
• ISSN: 0022-3646; 1529-8817
• DOI: 10.1046/j.1529-8817.1999.00001-157.x

The abundance of phycoerythrin‐containing cyanobacteria and picoeukaryotes in water samples from the Scripps Institution of Oceanography pier have been followed at least weekly for more than two years using flow cytometry. These cyanobacteria show a seasonal cycle with generally lower cell numbers during the winter, a “bloom” as water temperatures increase, and higher cell numbers during the summer. However the population abundance appears to be more variable and the magnitude of the annual change in cell number is less than reported for coastal Massachusetts by Waterbury et al. (1986). Isolates have been obtained from pier samples and genetic characterization using rpoC1 (RNA polymerase) sequence data is in progress. The PUB:PEB chromophore ratios of isolates assayed using fluorescence excitation spectra range from about 0.4 (low PUB) to 0.7 (mid‐PUB) for isolates grown under white light. The physiological and genetic characterization of isolates is being used to examine the similarities and differences of cyanobacterial populations from different coastal regimes. Similarly a picoeukaryote has been isolated that has a flow cytometric signature similar to the natural population. It appears to be a small nonmotile prasinophyte.