FOCI Standard Operating Instructions
January 2002
3.2.7 Methot Trawls - The Methot trawl is deployed off the
stern of the vessel, with the stern platform removed, using the Marco winch
equipped with at least 1,000 meters of 7/16” wire rope with a Safe Working
Load (SWL) of 2 tons. A ScanMar Model S40 acoustical depth sensor
with readout in the trawl house will be used to receive real-time depth
information. The ScanMar transducer is mounted on the ship's centerboard.
A scientist or survey technician in the trawl house will relay orders for
stopping and starting the winch to the winch operator based on trawl depth;
otherwise, deployment and retrieval will be the responsibility of the ship’s
crew. The ship's speed should be 2.5 to 3.0 knots through the water.
This trawl will be deployed at 30-40 meters per minute and retrieved at
20 meters per minute. Tows will be either oblique or stepped oblique,
generally from 100 meters to the surface. Methot trawls may be conducted
in daytime or at night with little or no advanced warning; where and when
the trawl will be conducted depends on plankton catches or acoustic sign.
Therefore, the trawl will need to be activated quickly with little time
lost. Location and time of tows is at the discretion of the Chief
Scientist or Scientific Watch Leader.
allen.macklin@noaa.gov