GB2026291A - Transporting Fish - Google Patents

Abstract

Transporting apparatus for live river fish comprises a tank 12 containing a pump 28 and an aerator 24 located above the water level. The pump 28 circulates water through the aerator 24 where the water dissolves air and returns to the tank simulating natural conditions in a river. <IMAGE>

Description

SPECIFICATION Transporting apparatus This invention relates to an apparatus for transporting live fish, especially river fish.

Fish which live in running water, such as river fish, and especially trout, are difficult to transport live. One proposed method involves carrying the fish in insulated containers. The water in the containers is cooled down slowly, over about three hours, until it is close to freezing point. This has the effect of slowing down the metabolism of the fish so that they use less oxygen on the journey. At the destination the water is allowed to warm up again slowly. This method is lengthy to set up and in any event can only be used for fairly short journeys or the fish will be adversely effected by lack of oxygen. An alternative proposal provides a tank of water through which oxygen is bubbled. Although this can in theory be used for journeys of indefinite length, in practice the control of the oxygen supply is critical.Too much oxygen is detrimental to the fish since oxygen bubbles can form within their bodies; and of course too little will result in asphyxiation. The system is also wasteful of oxygen, since most does not dissolve, and expensive.

The invention seeks to provide an apparatus for transporting fish which reduces or overcomes the disadvantages of previous proposals, and in an inexpensive manner simulates natural conditions.

According to the present invention there is provided an apparatus for transporting fish which comprises a vessel capable of holding water and fish, an aerator above the water level and means for circulating water from the vessel through the aerator.

By circulating water from the vessel through the aerator, natural aeration of running water is simulated and the fish may be kept healthy as long as desired.

The vessel may be a tank of any suitable size and construction, and may be adapted for mounting on a trailer or wagon, or may be provided with a suspension system and wheels of its own.

The aerator should have a large number of small water outlets, and/or leave a large surface area over which the water must run, to allow the water to dissolve sufficient air before returning to the tank. In this regard the zone above the water level containing the aerator should be well ventilated or even provided with a forced stream of air to ensure adequate air for aeration.

The means for circulating water from the vessel to the aerator may conveniently be a pump, which may advantageously be driven from the power source of the transporting vehicle, e.g. the power take off of a tractor.

If desired compressed air may be provided for 'topping up' the aeration under certain conditions, for example if the pump is not being driven while the transporting vehicle is stationary.

The invention will be described further, by way of example, with reference to the accompanying drawings, in which: Figure 1 is a diagrammatic side view of an apparatus according to the invention; and Figure 2 is a modified form of the apparatus.

Referring to the drawings, the apparatus 10 comprises a vessel in the form of a rectangular metal tank 1 2 mounted on a chassis 14 having an axle and wheels 1 6 and means 1 8 for coupling to a tractor suit. The tank 1 2 is filled with water in which fish may be placed.

Baffles 20 depend into the water to reduce disturbance of the water while the apparatus is moving. The tank 1 2 has a lid 22 hinged to it for closing the apparatus when in transit.

An aerator 24 is connected through a pipe 26 to a pump 28 at the bottom of the tank.

The pump draws in water from near the bottom of the tank and circulates it through the aerator 24 from where it trickles back into the tank. The lid 22 has an air intake 30 to ensure an adequate air supply in the vicinity of the aerator 24. Water is forced out of holes 32 in the aerator ensuring intimate contact with the air giving maximum dissolution of air. In the embodiment shown in Fig. 1, the pump 28 is driven by means of a belt 34 from the axle of the apparatus. Consequently when the apparatus is stationary for a long period additional aeration may be required, and this is provided by an air compressor 36.

The apparatus may be filled and/or emptied conveniently by means of a flexible outlet pipe 38.

The apparatus of the invention simulates natural running water conditions, the spray of water from the aerator being analogous to a waterfall in a river, and is eminently suitable for transporting river fish, and especially trout.

It will be appreciated that, although the apparatus of the invention is intended primarily for transporting live fish, it may also be used for other purposes, e.g. temporarily storing fish.

Various modifications of the apparatus may be made without departing from the scope of the invention. For instance, instead of the baffles 20, floating sheets or blocks of, for example, expanded polystyrene material 40, preferably perforated to allow free access of the aerated water, may be employed. For lightness, the tank itself may be made from materials such as glass fibre reinforced plastics. The compressor, where fitted, may be driven from the same power source as the pump, which may be from the vehicle or an independent motor. In the embodiment of Fig.

2, the compressor has a coupling 42 connectable to the vehicle power take off. When a compressor is employed it is preferred to bleed air into the circulating system, e.g. into the pipe 26, rather than directly into the tank.

A non-return valve is preferably used between the compressor and the circulating system.

Claims (10)

1. An apparatus for transporting fish which comprises a vessel capable of holding water and fish, an aerator above the water level and means for circulating water from the vessel through the aerator.

2. An apparatus as claimed 1 wherein the vessel is a tank mounted on a trailer.

3. An apparatus as claimed in either of claims 1 or 2 in which the aerator has a large number of small water outlets and/or has a large surface area over which water must run, to ensure adequate aeration.

4. An apparatus as claimed in any of claims 1 to 3 in which the zone above the water level containing the aerator is well ventilated.

5. An apparatus as claimed in any of claims 1 to 4 in which the means for circulating the water is a pump.

6. An apparatus as claimed in claim 5 in which the pump is driven from a power take off on the vehicle.

7. An apparatus as claimed in claim 5 in which the pump is driven by a belt from the wheei of the trailer.

8. An apparatus as claimed in any of claims 1 to 7 additionally including a compressor for providing additional aeration.

9. An apparatus as claimed in any of claims 1 to 8 in which floating sheets of expanded polystyrene are provided to reduce disturbance of the water while the vehicle is moving.

10. An apparatus for transporting fish substantially as hereinbefore described with reference to and as illustrated in Fig. 1 or Fig.

2 of the accompanying drawings.