This is a vertical tow, with the ship's speed used only to maintain a 0° (vertical) wire angle.  The telemetering Sea-Bird Electronics SBE 19 SEACAT will be used on the wire to determine the depth, stopping at 70 meters, or 10 meters off bottom in the case of shallow water, and to obtain environmental data that will be saved for each haul.  A scientist will be stationed in Data Plot to monitor the SEACAT and to inform the ship’s survey technician and winch operator when the desired gear depth is reached.  The primary SEACAT will be provided by the Pacific Marine Environmental Laboratory (PMEL) and the backup SEACAT will be provided by the ship.  Before the SEACAT is terminated on the wire by the ship’s electronic technician and the survey technician, a PMEL scientist will note the identification number of the unit and provide the proper calibration file for the computer when the SEACAT from PMEL is used.  Personnel from PMEL will provide the acquisition computer and monitor.  There is no need for the SEACAT data to be displayed on the SCS.

The bongo is lowered at 25-30 meters per minute to the specified gear depth using the starboard Markey oceanographic winch outfitted with a 2-layer, 3-conductor, 0.322" oceanographic wire. During retrieval, the wire haul back speed will be 10 meters per minute.  The tow will be timed starting when the net is being retrieved.  The nets will not be rinsed when they return to the deck to prevent damage to live larvae.  Each cod-end should be held vertical in a clean 5-gallon bucket so that when the cod-ends are detached from the bongo net the water and larvae will spill into the buckets.  The contents of the cod-ends and buckets are then carefully poured into a bowl over ice and sorted quickly for live larvae.  The larvae are then preserved immediately, as specified in the FOCI Field Manual or sample collection request forms.

Flow meters in the nets record the amount of water filtered.  If there are no live larvae found, or few larvae are found in the cod-ends, then another live tow may be requested by the Chief Scientist.  Once the required number of larvae is obtained, the nets and cod-ends should be rinsed to prevent contamination of a quantitative bongo tow.  At the end of the survey, the Chief Survey Technician will provide the Chief Scientist with a copy of the acquired data from the SEACAT and the scientists on watch are responsible for recording times and maximum depth on the Cruise Operations Database (COD).