The Continuous Underway Fish Egg Sampler (CUFES) is an instrument used to collect pelagic eggs of fish and related hydrographic data from ~3m depth on a moving ship. These samples and data, typically collected during winter and spring cruises, are used to investigate spawning habitat and estimate spawning biomass. When large aggregations of fish eggs are present, Pair-o-vet vertical net tows are done to calibrate egg density.
The CUFES system consists of a inboard or outboard submersible pump, concentrator and sample collector. Water is pumped continuously from a fixed depth (surface to 3 m) to the concentrator on board ship. Eggs and similarly-sized particles are retained in the sample collector. CUFES operates continuously under most sea conditions.
Outboard Submersible Pump
A semi-vortex, submersible pump is attached to the bottom of a vertical, steel pipe fixed rigidly to the ship at two points. It is fixed to the ship by a horizontal metal pipe and clamps, one of which is either welded or bolted to the gunwale. The pipe is held firmly in a brace attached to the ship's hull 10 - 100 cm above the water line and by fore and aft guy wires. The vertical pipe can be pivoted into a horizontal position at the gunwale to allow access to the pump. The pump is normally powered by 220/460 VAC, three phase, but other specified voltages are available on special order. Water flows from the pump at 500 - 700 liters/min through a 75 mm diameter flexible hose situated inside the vertical pipe.
Inboard Submersible Pump (Alternate Method)
The semi-vortex submersible pump may be mounted inside the vessel with proper fittings installed on new or existing overboard pipe connections. The pump is placed in a sealed stainless steel box and connects to a sea chest. Water is drawn from 3 - 6 m below the waterline and then pumped to the Concentrator for processing.
A Nitex net oscillates at 6 Hz over a 2 cm range in a watertight aluminum box with a clear acrylic front panel. Flow in the 75 mm hose from the pump enters the box and net at the top. Eggs and other particles are concentrated in a 10 - 30 liter/min flow, leaving the box at its lower front. The filtrate is discharged through two 75 mm hoses at the side of the box. The Nitex net is stretched taut in a frame which moves laterally on three guide rods. A .33 hp, 110/220 VAC motor and reducing gearbox mounted behind the watertight box drives the net frame via a shaft, watertight penetration with double bearings and seal and eccentric drive gear.
A sliding plate directs flow in 19 mm Tygon tubing from the concentrator to one side of a knife-edge. Below, eggs and other particles are retained in a sample cup with a Nitex netting bottom. Flow is redirected manually by the user from one side to the other of the knife-edge, providing continuous collection of samples over user defined integration periods.
EDAS Data aquisition System
The CUFES system is enhanced by the concurrent aquisition of data for time and position, as well as flow rate, temperature, conductivity, chlorophyll and fluorescence. An optional, integrated EDAS Data aquisition System with custom software is available. Please call for specifications or to discuss your requirements.
CUFES system. Includes: overboard pipe system, pump, concentrator and sample collector, four guy wires and attachment fittings, shackles, nuts and bolts, hoses and tubing (except *75 mm dia suction hose) and spares suite.
Pump, spare DVSU62, 3 hp 3 phase (specify voltage & Hz)
Motor, concentrator spare 110/220 VAC, 50/60 Hz
Some information & images courtesy of Ocean Instruments, manufacturer of CUFES.