Instrument: MOCNESS.25

Dataset: 
Tioga MOCNESS logs
Instrument: 
MOCNESS.25
Instrument Short Name: MOC.25
Community Standard Description
(http://vocab.nerc.ac.uk/collection/L22/current/NETT0097/)
Instrument Description:

The Multiple Opening/Closing Net and Environmental Sensing System or MOCNESS is a family of net systems based on the Tucker Trawl principle. The MOCNESS-1/4 carries nine 1/4-m2 nets usually of 64 micrometer mesh and is used to sample the larger micro-zooplankton.

PI supplied instrument name: MOC.25
Dataset-specific description

The MOCNESS was equipped with nine 150-um mesh nets (nets 0-8). The underwater unit used was #169; temperature probe was #535 and conductivity probe was #120. A connector cable converting from the 4-pin Seacon connector at the wet end of the 0.322" EM cable on the Tioga's winch to the 2-pin EO connector required by the MOCNESS was required. Both the MOCNESS and CTD required the same pins and so the dry end connectors needed to be swapped out between operations. To simplify this change over, for this cruise, Captain Ken Houtler had a new connector made for the wheelhouse, connecting the ground and first pin wires in the wheelhouse junction box to a BNC connector. The MOC or CTD deck units were then connected to this BNC.

In addition to the standard temperature and conductivity probes the system also had a beta-type strobe-light unit for reducing avoidance of the nets by some zooplankton and possibly small fish. The strobe system has two units each with 12 LED sets (LUXEON Rebel LED) with peak output between 490-520 nm. The LEDs are powered by the MOCNESS battery and their pulse width, amplitude, flash rate period, and on/off are controlled by the MOCNESS software. The 5A fuse in the underwater unit that connects to the strobe blew on the first net cast and the canister was subsequently disconnected from the system.