Instrument: Vertical Multi-layer Plankton Sampler

The Vertical Multiple Plankton Sampler (VMPS), a variation of the multiple plankton sampler (MPS), is a specially designed opening-closing, multi-layer net system used for collecting zooplankton (Terazaki and Tomatsu, 1997). The mesh size and mouth opening can vary depending on research focus. The VMPS is towed through depth ranges with nets closed at known intervals to yield estimations of standing stock, vertical distribution and diel vertical migration.

The VMPS as described by Wiebe and Benfield (2003) is named the Ocean Research Institute Vertical Multiple Plankton Sampler (ORI-VMPS) with specifications: 100 cm x 100 cm rectangular mouth opening multiple net system that can be equipped with 4 to 10 nets, 510 cm long with 0.33 mm nylon mesh. Nets are opened/closed by surface commands down transmitted via conduction cable to an underwater unit (see Plate 31 C (Wiebe and Benfield, 2003)).

References:
Terazaki, M. and Tomatsu, C. (1997). A vertical multiple opening and closing plankton sampler. Journal of Advanced Marine Science Technological Society, 3, 127-132.

Wiebe, Peter H. and Mark C. Benfield, 2003. From the Hensen net toward four-dimensional biological oceanography. Progress in Oceanography, 56, pp. 118.