JPR Advance Access originally published online on June 23, 2006
Journal of Plankton Research 2006 28(9):831-840; doi:10.1093/plankt/fbl018
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The effect of nutrient availability and temperature on chain length of the diatom, Skeletonema costatum
1 Marine Science Department, University of Hawaii at Hilo, 200 West Kawili Street, Hilo, Hi 96720, USA and 2 Romberg Tiburon Center for Environmental Studies, San Francisco State University, 3152 Paradise Drive, Tiburon, CA 94920, USA
* Corresponding Author: misakita{at}hawaii.edu
Received January 9, 2006; accepted in principle March 14, 2006; accepted for publication June 12, 2006; published online June 23, 2006
Communicating editor: K.J. Flynn
We determined the effects of temperature and nutrients on the chain length of a diatom, Skeletonema costatum, in batch culture and enclosure experiments with estuarine water from San Francisco Bay, USA, using the recently developed CytoBuoy flow cytometer. Determination of the number of cells per diatom chain by CytoBuoy flow cytometer and associated software correlated well with but was much more precise and time efficient than microscopic quantification. Increasing temperatures (from 6, 8 to 17°C) and nutrient concentrations induced high growth rates and dominance by longer chains in a cultured S. costatum strain that was originally acclimatized to a temperature range of 1130°C. Similarly, a positive correlation between growth rate and chain length was observed in S. costatum in batch culture and natural communities in enclosure experiments. Maximal chain lengths of S. costatum were greater in natural populations than in the batch culture. Longer chains affect sinking rates and thus likely help the diatom remain suspended in the upper part of the water column where physical and chemical parameters are more favorable for growth.