Instrument: MOCNESS-1D

Dataset: 
Copepod abundance - MOCNESS
Instrument: 
MOCNESS-1D
Instrument Short Name: MOC1D
Instrument Description:

The Double MOCNESS 1D carries 20 1m2 nets usually of mesh size 335micron and is designed to collect macrozooplankton.

This MOCNESS system uses the same underwater and shipboard electronic system for operation and data acquisition as other MOCNESS systems. The nets are opened and closed sequentially by commands transmitted from the surface deck unit through a single conducting cable to the underwater unit. The command circuit has a provision to permit commands to be sent to either the left of right set of nets when using the double MOCNESS-1D. - from Wiebe et al, 1985.

PI supplied instrument name: Double MOCNESS
Dataset-specific description

The double MOCNESS is configured like two 1m2 MOCNESS systems attached side-by-side and carries twenty nets (Wiebe et al., 1985). The MOCNESS is designed to fish with a 1m2 net mouth area when towed at a 45o angle (Wiebe et al., 1976). A flow meter mounted on the frame, just ahead of the net mouth, allowed calculation of the volume of water sampled (Wiebe et al., 1976; 1985). The data-acquisition software used angle information when calculating volume of water filtered. The double MOCNESS was fitted with 153um mesh nets and included, in addition to the standard conductivity (Sea-Bird SBE4) and temperature (Sea-Bird SBE 3) sensors, a transmissometer (SeaTech, 25cm beam) and an oxygen probe (Sea-Bird SBE 13). The double MOCNESS was towed behind the ship at a speed of 1.5 to 2 knots (2.8-3.7 km h-1) through the water. Winch speed generally ranged from 10 to 25m min-1 during deployment and 5 to 15m min-1 during recovery. Target sampling depths for this report were 300-250m, 250-200m, 200-150m, 150-100m, 100-75m, 75-50m, 50-25m and 25m to surface.