Vertical Microscale Distribution of Phytoplankton in Relation to the Thermocline

Abstract

an in situ fluorometer, distinct chlorophyll maxima were measured within and below a seasonal thermocline in the Baltic Sea. At an average thickness of 34 cm, these chlorophyll layers exceeded surface chlorophyll concentrations by a factor of between 8 to 10. The average vertical distance between layers which contained four times the average concentration was found to be about 3.3 m, horizontal extension some 10 m. The chlorophyll layers are assumed to be a dynamic feature formed or maintained locally. A conceptual model is considered that might help to explain the mechanism.