MOCNESS is the acronym for ''Multiple Opening/Closing Net and Environmental Sensing System'' and is a net system for
plankton
Plankton are the diverse collection of organisms found in water (or air) that are unable to propel themselves against a current (or wind). The individual organisms constituting plankton are called plankters. In the ocean, they provide a cruc ...
in the ocean. The system is towed behind a
research vessel
A research vessel (RV or R/V) is a ship or boat designed, modified, or equipped to carry out research at sea. Research vessels carry out a number of roles. Some of these roles can be combined into a single vessel but others require a dedicate ...
with a speed of up to 2.5 knots and consists of five to twenty nets with a mesh size from 64 μm to 3 mm and an area of 0.25 to 20 m
2 (although the last one is a 2x10 m systems) which are opened and closed computer controlled at desired depth. The net enables biologists to catch
zooplankton
Zooplankton are the animal component of the planktonic community ("zoo" comes from the Greek word for ''animal''). Plankton are aquatic organisms that are unable to swim effectively against currents, and consequently drift or are carried along by ...
and
nekton
Nekton or necton (from the ) refers to the actively swimming aquatic organisms in a body of water. The term was proposed by German biologist Ernst Haeckel to differentiate between the active swimmers in a body of water, and the passive organisms t ...
in various depth horizons typically anywhere in the upper 6000 m of the oceans. All MOCNESS systems are capable of sampling to 6000 meters depth (10,000 psi). The system includes SeaBird probes to measure salinity and temperature at sampling depths, as well as optional dissolved oxygen, PAR (photosynthetically available light), transmissometry and fluorescence sensors.
References
P. H. Wiebe et al., 1985, New development in the MOCNESS, an apparatus for sampling zooplankton and micronekton, Marine Biology, 87(3), 313-323, {{doi, 10.1007/BF00397811
Planktology