Application of a compact automatic sea water sampler to high frequency picoplankton studies

This note describes a compact automatic sampler des~gned to collect small water samples (about 3 ml) at high frequency (minutes to hours), which is very useful for marine microbial data acquisition. The devlce consists of a microprocessor card controlling, through an interface and a BASIC program, a fraction collector, a peristaltic pump and a set of tube-pinching electrovalves. Samples are kept at 4C until analysis or fixation, which appears to result in minimal effects on parameters such as abundance, size or pigment fluorescence.