WO2019138110A1

WO2019138110A1 - Underwater trap systems

Info

Publication number: WO2019138110A1
Application number: PCT/EP2019/050817
Authority: WO
Inventors: Gaute RINGVOLD
Original assignee: Alba Gruppen As
Current assignee: Alba Gruppen As
Priority date: 2018-01-12
Filing date: 2019-01-14
Publication date: 2019-07-18
Anticipated expiration: 2020-07-12
Also published as: GB201811136D0; GB201800541D0

Abstract

In one aspect, a reconfigurable snail and crab/lobster trap with hinged body parts, a funnel shaped entrance part and one or more weights. The trap is configurable as a snail trap and also as a crab/lobster trap. A smart trap system is also described.

Description

UNDERWATER TRAP SYSTEMS

FIELD OF THE INVENTION

This invention relates to underwater traps, particularly but not exclusively for snails, crabs, fish and the like.

BACKGROUND TO THE INVENTION

There is a need for increased automation in underwater applications such as fishing, seabed mapping, seabed cleaning and underwater research applications. Currently a fisherman attaches traps with ropes to a boat and manually checks and collects various sea produce. Bad environmental conditions can make fishing a high-risk profession. Also, fishing can be time consuming and unprofitable due to the probabilistic nature of conventional fishing methods. There is also a need for improved underwater trap systems.

SUMMARY OF THE INVENTION

According a first innovative aspect there is therefore provided an underwater positioning system for a trap. The underwater positioning system comprises an attachment for attaching the trap. The underwater positioning system also comprises locomotion means to move the trap laterally and/or vertically. An electronic controller is coupled to a communications interface to receive control commands, and to control the locomotion means to move the trap in response to the control commands.

Such an arrangement can facilitate control of the underwater positioning system for attaching traps, in particular automatic control. It may also make fishing simpler, efficient and safer since the system is autonomous as it can be operated with an automatic boat and a logistic centre on the shore.

The trap may be a free-floating underwater trap, e.g. associated with an underwater drone. The locomotion means may comprise any suitable means including, but not limited to propellers and jet propulsion. In one implementation the underwater positioning system is configured to move the trap in a horizontal and/or vertical direction. Thus the locomotion means may comprises one or more propellers. A vertical movement may additionally or alternatively be achieved by a floating buoy design. The communications interface may be wireless, for example when the device/system is on the water surface, and/or it may be wired, for example via a cable, for example as an emergency backup. The wireless communications system may be a sonar communications system. A terminal may be provided either in the boat or at the shore to communicate with the electronic controller to enable a user to issue the control commands. The device/system may operate autonomously, that is it may deploy to a trap location and/or rise to the surface automatically without the need for direct external control.

In some implementations the underwater positioning system includes one or more positioning sensing devices coupled to the electronic controller. The electronic controller may then control the positioning sensing devices to determine position of the trap in response to a signal from said one or positioning sensing devices. The position sensing devices may include but are not limited to: a global positioning system (GPS) sensor and/or accelerometer (for example, to determine the position on the surface and the relative displacement from that position when underwater), a light sensor, and a camera (in conjunction with suitable processing).

In some implementations the underwater positioning system further includes one or more trap condition sensing devices coupled to the electronic controller. The electronic controller may then control condition sensing devices to determine a condition of the trap in response to a signal from said one or trap condition sensing devices. For example, the condition sensing device may sense whether the trap is full, empty and/or when the trap has run out of bait. Examples of the condition sensing devices include sensors, camera, robotic arms or computed tomography (CT) scanners.

In some preferred implementations the trap may be moved to a new position automatically, that is without specific user control. Thus the electronic controller is configured to perform a sequence of movement operations in response to a local or remote signal to automatically move the trap to a new trap position in response to a local or remote trap relocation request. The rotation/orientation of a trap may be varied in a similar manner.

For example, a signal from a system located in the positioning system based on the stock of the species being captured or the amount time spent by a trap in a particular location. For example, a trap may be relocated at time intervals, say of every 8 hours, if a trap is not full to allow a trap to operate over an extended period of time. Thus a trap may be moved when there is local depletion of fishing stock.

Additionally or alternatively the trap may be moved to a new position in response to a trap relocation request by a user in a boat or a user in a logistic centre on the shore.

The system may detect depletion of target stock in a location of the trap to generate the trap relocation request. For example, the system may use sonar, camera or other techniques to detect or count the target stock such as fish and/or other sea creatures.

The electronic controller may be configured to autonomously move the trap to a new trap position without needing an external control signal. For example the movement may be based on/responsive to a detected stock level and/or elapsed time. The system may operate in a fully autonomous manner.

In some implementations the underwater positioning system the electronic controller is configured to move the trap automatically into an optimal position. An optimal position may be defined as a trap location or a biotope for a particular type of species or a location on the sea bed where a particular species is found in abundance. This may be determined based on a map, using the position sensors.

In some implementations the system may further comprise rotation means to rotate the trap about the attachment. The rotation means may comprise means to control horizontal thruster, for example to provide oppositely directed thrust. The rotation means may be configured for control by the electronic controller.

The trap may be configured to catch a species based on weight, size, type, and/or gender. The system may include a screening mechanism, for example to selectively catch and/or release catch, for example in order to comply with legal requirements.

The electronic controller may be configured to return the trap to the surface automatically after a pre-specified time, and/or in response to an external signal, and/or the positioning system may include a self-abort security mechanism to return the trap to the surface when an abort condition is detected. An abort condition may comprise component failure and or power (battery) failure. The trap may be configured to catch a plurality of different species of animal, and a different a part of the trap may be allocated to trapping each of the different species. For example a trap may be configured to catch both fish and crabs, catching fish at the top and crabs/snails at the bottom.

A light may attached to the trap to attract and trap a bait species, such as krill, in the trap, such that the bait species attracts a target species, such as fish, to the trap.

A trap may further comprise one or more supports to support the trap at a location which is displaced away from the sea floor. A trap may thus be configured to catch a target species and to restrict other species entering the trap. The supports may be adjustable, and remotely and/or locally controllable; the supports may comprise legs. Thus the system may automatically lift a trap off the sea bed once deployed, for example to inhibit crabs from entering a trap.

The underwater positioning system may be operable in a swarm mode in which a plurality of underwater positioning systems work in coordination with each other, typically simultaneously, to move their respective traps. This can improve the efficiency of fishing whilst keeping taps in the swarm from colliding. The traps may include mutual wireless communication means, for example sonar communication, to facilitate this behaviour.

The trap may be configured to self-attach to an anchor, for example to attach to the seabed, autonomously or in response to an external control signal. For example a chain/line may be provided fastened to an attachment on the sea bed, and a trap may be configured to hook-in and/or hook-off the chain/line autonomously and/or under control of a fisherman.

The system may have a modular or“plug and play” design to facilitate changing the size of the traps, and/or the underwater positioning system/controller (for example the degree of “intelligence” in the autonomous operation). This facilitates the use of simpler, smaller traps close to shore, and larger, more autonomous variants further out at sea. An underwater positioning system in combination with a trap, as described above, can be used for fishing.

The electronic controller for the underwater positioning system may operate under the control of stored program code, or may comprise dedicated hardware implemented in electronic circuitry, or may comprise a combination of some dedicated hardware modules and some systems under program control. Thus, for example, the controller may comprise a processor coupled to working memory and to non-volatile memory storing processor control code, as well as to one or more wired or wireless communications interfaces. The functionality of the controller may be distributed between a plurality of modules in communication with one another, for example partially in an underwater system and partially in a shipping vessel-borne system, and/or it may be implemented partially or wholly in the cloud.

Advantages of embodiments of an underwater positioning system incorporating these features may include easier control of the traps, potentially avoiding the need for assistance from an operator on the boat, the ability to operate for an extended period of time or in bad weather, safer operation, an improved ability to retrieve traps when they are full, an improved ability to position the traps in desirable location, for example in a biotope for a particular type of species. All of the above described features lead to an efficient, safer and a scalable fishing system.

In a second aspect there is provided an underwater lobster/crab/snail trap system, comprising: at least one trap for catching and retaining lobsters, crabs and/or snails; a buoy; a chain or rope linking the at least one trap to the buoy; and a wired electrical connection linking the at least one trap to the buoy; wherein the at least one trap comprises one or more sensors to sense a condition of the trap; and wherein the buoy includes an electronic subsystem, coupled to the trap via the wired electrical connection to harvest data derived from the one or more sensors and communicate trap condition data representing the condition of the trap to a base station.

In some implementations the chain/rope between the traps helps to locate the traps, and also facilitates the use of a wired connection between the trap(s) and the buoy which can carry data and/or video to the surface. This in turn facilitates provision of a software system which can provide fisherman with information such as which trap(s) have catch in them, and optionally how much, a remaining lifetime of bait in the trap before it should be changed, and so forth. For example data may be provided indicating which traps have crabs/lobsters in them, and optionally how many. This can save fisherman time and also facilitates deploying more traps. Thus the trap condition data may indicate data regarding catch in the trap and/or a condition of bait in the trap.

The sensor data from the trap(s) may be provided to the electronic subsystem in the buoy in raw or processed form the latter, for example, as trap condition data specifying a condition of a trap as described above. Trap condition data may be provided wirelessly to the base station, typically an electronic controller on a fisherman’s boat which may be in the form of a laptop or tablet computer. The base station may be configured to perform additional functions, for example mapping the trap(s) and/or predict one or more optimal locations at which to deploy the traps. The latter may depend, for example, on the shape of the seabed, the local biological footprint, currents, temperature, time of day, time of year, weather/predicted weather, and so forth.

In some implementations the trap system comprising a chain of the traps, each trap linked to an adjacent trap by a respective chain or rope and wired electrical connection. An end trap of the chain may be linked to the buoy. The electronic subsystem may be configured to harvest data from each trap relating to a condition of the trap and communicate the condition of each of the traps to the base station. The wired connection between the traps may be a serial and/or parallel connection, for example a serial/parallel bus or daisy chain connection. The connection or bus may carry data from the trap(s) to the buoy and/or power from the buoy to the trap(s) and/or the trap(s) may each have a respective local power supply. In some implementations the buoy may have one or more solar cells or panels to provide power such a trickle charge power supply, to the trap(s).

In some implementations each trap has an address or other identifier. Thus in some implementations the traps are individually addressable and have an associated local processor. Each trap may include a sensing system comprising one or more sensors, a processor to communicate with the electronic subsystem, and may have a trap identifier for the trap, for example stored in memory, or set with switches, links or the like. In implementations the electronic subsystem is configured to harvest the data derived from the one or more sensors and to communicate trap condition data in association with the trap identifier to the buoy and thence to the base station.

The one or more sensors to sense a condition of the trap may include one or more of a camera, a movement sensor (to sense movement of contents of the trap such as catch or bait; and/or to sense movement of the trap itself), and a depth sensor. The sensors may also include a visual and/or UV or IR light to illuminate contents of the trap. Other sensors which may be included comprises one or more of: a mechanical sensor for example to detect the presence of catch and/or absence of bait, a temperature sensor, a position sensor, and a water contamination sensor. In some implementations a sensor to sense a condition of the trap as previously described may comprise a camera and illumination system, operating in conjunction with image processing software in the trap, buoy, and/or base station. The buoy may include a global positioning system (GPS) sensor to report a location of the buoy and hence of at least one trap.

The underwater trap system may include locomotion means as previously described, to move the trap laterally and/or vertically, and a trap electronic controller to receive control commands and to control the locomotion means to move the trap in response to the control commands.

More generally the skilled person will recognise that features of the first and second aspects of the system may be combined. Similarly a snail trap and/or combination trap as described below may be used in the underwater lobster/crab/snail trap system. Thus snail trap and/or combination trap may be equipped with one or more sensors. More generally any of the traps in the system may include an escape aperture as described later.

In a third aspect there is provided a reconfigurable, in effect combined, snail and crab/lobster trap. The trap comprises first and second hinged body parts. Each hinged body part may be hinged along a longitudinal edge so that the body part can be opened, or hinged shut to define a tubular body part. The first and second hinged body parts may be longitudinally joinable to define an extended body unit.

A funnel shaped entrance part may be provided for a first end of each of the body parts. This may be a separate, removable part which, for example, fits into a moulded slot; it may be locked in position at the first end of the body part when the body part is hinged shut. Alternatively the funnel shaped entrance part may be formed as part of the body part, for example integrally moulded with the body part.

One or more weights may be provided for a second, opposite end of each of the body parts. In some implementations each of these may be a separate part which, for example, fits into a moulded slot; it may be locked in position at the first end of the body part when the body part is hinged shut. Alternatively the one or more weights may be formed as part of the body part, for example integrally moulded with the body part. In some implementations the weights may comprise metal encased in plastic. In some other applications a weight may comprises an enclosure to be filled with any suitable heavy material such as local rocks and/or sand.

In some implementations the reconfigurable snail and crab/lobster trap is configurable as a snail trap in which one of the body parts is hinged shut to define the tubular body part. Then the funnel shaped entrance part is located at a first end of the tubular body part and the one or more weights are located at a second opposite end of the tubular body part (the first and second ends of the tubular body part corresponding to the first and second ends of the hinged body parts). In use the snail trap is vertically orientated with the second end on the water bed, that is sea, lake or river bed/bottom, and the first end displaced away from the water bed with the funnel shaped entrance part facing upwards. The other of the body parts may be similarly configured to provide a second snail trap.

In some implementations the reconfigurable snail and crab/lobster trap is also configurable as a crab/lobster trap in which the first and second hinged body parts are longitudinally joined and hinged shut to define the to define extended body unit. One of the funnel shaped entrance parts may then be located at each end of the extended body unit. The one or more weights may be located in an inner region of the extended body unit, for example at a central or joining location. In use the crab/lobster trap is horizontally orientated with the funnel shaped entrance parts is located near the water bed.

In some implementations the first body part has locking pins extending perpendicular to a longitudinal direction defined by the longitudinal edge. These may engage with corresponding formations, for example apertures, on the second body part so that the second body part can be slid sideways over the pins when the first and second body parts are hinged open (were sideways denotes perpendicular to the longitudinal edge). When the first and second body parts are hinged shut the pins on either side of a hinge of the first body part may point in opposite directions such that when hinged shut the first and second body parts are (longitudinally) locked together.

Each of the hinged body parts may comprise first and second half tubes hinged along their longitudinal edge for example fabricated from rigid plastic. When hinged shut they may define a tube. The tube may have faceted walls; for example it may have six facets defining a hexagonal cross-section. An access portal or door may be provided in one or more of the facets to facilitate removal of catch. Two of the hinged body parts may be joined end-to-end to define a longer, for example double length tube. This may have a funnel-shaped opening at each end and the weights in the middle as previously described. A mesh at one end of each of the hinged body parts may define a central double mesh with a space in between for bait when the hinged body parts are joined.

Each of the half tubes may be configured to mount the one or weights in two arrangements, for example by means of a groove, slot or moulded formation. A first arrangement, for the snail trap, may be one in which the one or more weights are circumferentially disposed at the second end of the tubular body part. A second arrangement, for the crab/lobster trap, may be one in which the one or more weights are disposed on one of the half tubes. In some implementations the weights are detachable and repositionable so that they can be moved from a“half-pipe” groove/slot at the bottom of the tube when the trap is horizontal into a ring-shaped groove/slot extending around the circumference of the tube when the trap is vertical.

As previously mentioned the trap may further comprise a removable mesh part configured to be mounted at the second end of each tubular body part. When the reconfigurable snail and crab/lobster trap is configured as a crab/lobster trap the mesh parts, when mounted, may define a bait cage. Optionally the mesh part may incorporate the one or more weights.

In a fifth aspect there is provided an underwater snail trap comprising a funnel shaped entrance part to funnel the snails into the trap, the funnel shaped entrance part defining one or more holes e.g. at an apex of the funnel to allow snails to enter the trap. The snail trap may have a rigid enclosure for trapped snails, which may be openable to retrieve the trapped snails; for example the enclosure may have a door/panel or may comprise two hinged halves. The funnel shaped entrance part may be located at a first end of the enclosure, uppermost when the trap is in use. One or more weights may be located at a second, opposite end of the enclosure. Thus in use, the snail trap is vertically orientated with the second end on the water bed, and the first end displaced away from the water bed with the funnel shaped entrance part facing upwards (and the funnel pointing downwards into the trap).

The snail trap may be closed at a lower end of the enclosure for example by means of a mesh at a lower end of the enclosure. The mesh may comprise a removable mesh part configured to attach on or within the lower end of the enclosure. Closing the snail trap at its lower end facilitates retrieving the trap, for example from the sea bed, by means of a rope or chain connected to a buoy. Use of a mesh facilitates water flow through the trap, and hence keeping the catch alive and healthy.

The snail trap may be configured such that two or more of the snail traps may be attached to one another, for example via a locking mechanism, to make a crab/lobster trap.

In some implementations of a reconfigurable snail and crab/lobster trap or underwater snail trap as described above the or each funnel shaped entrance part has one or more funnel side surfaces converging towards a funnel apex, and one or more escape apertures in the one or more funnel side surfaces to allow undersize crab/lobster catch to escape. In this way a trap with one or more escape apertures is usable as both a snail trap and a crab/lobster trap.

In some implementations of any type trap as described above may be made of material which slowly dissolves in sea water, for example over a period of 1-10 years. Various suitable polymers are known, for example a physical blend of polyethylene with starch.

The above described reconfigurable traps, and snail traps, may be used with the previously described underwater positioning system and/or underwater trap system. The above described reconfigurable traps, and snail traps, may be used in the sea or in a river or lake. The skilled person will appreciate that features/aspects of the traps and systems described herein may be combined.

BRIEF DESCRIPTION OF THE DRAWINGS

These and other aspects of the invention will now be further described, by way of example only, with reference to the accompanying figures in which:

Figure 1 illustrates, conceptually, an embodiment of an underwater positioning system for a trap and showing a top and side view of the positioning system;

Figure 2 shows an example of underwater positioning system being deployed where the control signals are provided by a user;

Figure 3 shows another example of underwater positioning system being deployed where the control signals are provided by an autonomous vehicle;

Figure 4 shows a block diagram of an underwater positioning system;

Figures 5a and 5b show, respectively, a block diagram of a smart trap system, and example user interfaces for the system;

Figures 6a and 6b show, respectively, a snail trap and details of the snail trap;

Figure 7a and 7b show, respectively, a crab/lobster trap and details of the crab/lobster trap;

Figures 8a-8d show parts for the traps of Figures 6 and 7, respectively illustrating half of a hinged body part which closes to define a tube, weights for the traps, a mesh part, and a funnel shaped entrance part; and

Figures 9a-9c illustrate a procedure for joining first and second hinged body parts for an extended length trap, and operation of a mechanism locking the body parts together. DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

Referring to Figure 1 , this illustrates one example of an underwater positioning system. Thus an underwater positioning system 100 comprises a body 102 with an attachment 104 for a cable 106, two lateral drive units 108a, b, for example each comprising one or more propellers and one vertical drive unit 110 comprising a propeller. A rotation link 1 12 may be provided between the cable attachment and the main body of the positioning system, to allow/control rotation of a trap 1 14 with respect to the attachment 104. The lateral and vertical drive units may be used to move the trap in a lateral and/or vertical direction. Alternatively, the vertical movement may be achieved using a floating buoy. The positioning system 100 has inherent or included buoyancy, which allows the trap to be oriented. The trap 114 may include legs 1 16 which lift the trap above the seabed. The legs may be adjustable, for example in length, and may be controlled autonomously or in response to signal from a user in a boat or a user located on the shore. An underwater positioning system controller (not shown in Figure 1 ) is included in the positioning system to control the drive units, positioning sensing devices, condition sensing devices and a communication interface.

Now referring to Figure 2, this shows an underwater positioning system controlled by a user located in a boat. A global positioning system (GPS) sensor 1 18 may be mounted on the positioning system for locating the trap when the positioning system is close to the surface of the water. Thus, a user can locate the positioning system and then collect the trap when it has reached the surface of the water. The user interface may send control commands to the positioning system and/or may display a view from one or more cameras associated with the positioning system. The control commands may include a trap move command, a trap return to the surface command, and/or higher level commands such as a command to automatically move a trap to a new location. In some embodiments the underwater positioning system may be configured to be attachable to currently used traps without significant modification to the design of the traps. The lateral and vertical drive units can be used to move the trap to the surface when a command is received from a user in the boat.

In Figure 3 the boat is un-manned, that is it may operate autonomously under software control, optionally in cooperation with software integrated into the underwater positioning system. A positioning system may be enabled to navigate the trap to a target position using the propellers. The position sensing of the positioning system may be performed using one or more of software, cameras, GPS navigation, and light (e.g. a beacon). The positioning system may have a 360 degree rotation capability as well as a propulsion system, to navigate the trap to a target location/orientation in two or three dimensions. The system may include one or more sensors to sense a condition of the trap, where a trap condition may comprise one or more of: a trap empty condition, a trap occupied condition, a trap full condition, and a trap out of bait condition. The condition sensing of the trap may be performed using software in conjunction with one or more of a weight sensor, a camera, one or more robotic arms, or even potentially even a computed tomography (CT) scanner.

Referring now to Figure 4, this shows a block diagram of a controller 200 for the underwater positioning system of Figure 1. In the illustrated embodiment this comprises a processor 202 coupled to non-volatile memory 204 storing code and data for operating the underwater positioning system, and to an internal bus 205. Control modules coupled to bus 205 include a vertical motion control module 207 to control the vertical motion drive unit 1 10, a lateral motion control module 206 to control the lateral motion drive units 108a,b, and a rotational motion control module 208 to control rotation link 1 12. Sensor modules coupled to bus 205 include GPS location sensor module 118, a weight sensor 216 (other sensors which may be included, such as a camera, are not shown).

Controller 200 preferably also incorporates one or more communications modules, such as a (bidirectional) user terminal communications module 218.

The controller may also have a power supply conditioner 222 to provide power for the controller, for example from a power supply via the cable and/or from a battery 224.

The code stored in non-volatile memory 204 may comprise, in embodiments, code to provide an interface to receive commands from a user control terminal, for example on a boat, code to interpret the commands, and code to control motion of the trap in accordance with the interpreted commands (operating and other low-level code is not shown for simplicity). The stored code (and data) to interpret the commands may include machine learning code and data, for example code and data for one or more trained neural networks which may be configured to automatically move the trap. The code may also include self-abort code to automatically inhibit operations of the positioning system when under automatic control for safety reasons, for example in an emergency the positioning system can be returned to the surface when an override command is received from a user in a boat or in a logistic centre on the shore.

Alternatively or additionally tools may be attached to the trap for mapping the seabed or propulsion such as propellers may be attached to the trap for improving the control of the trap.

Preferably a terminal is located in a boat or in a logistic centre on the shore; the terminal may provide a graphical user interface for remotely controlling the underwater positioning system.

Advantages of embodiments of the above-described underwater positioning system include reduced reliance on a human operator. This can improve safety and can increase efficiency, for example facilitating round-the-clock operation and can lead to better a health, safety, environment and quality management system for offshore applications. Environmental benefits include the ability to locate or track the traps, for example, this system could reduce the risk of‘ghost traps’ that is traps which are lost in the sea. Such ghost traps can continue fishing as sea animals are trapped and these may eventually become bait for other animals which may then also become trapped. Thus, the ghost traps can unnecessarily kill sea animals as these traps cannot be retrieved.

In addition to or instead of a trap the underwater positioning system may be provided with a sampling system to sample the sea (water) and/or sea bed, for example for retrieval of minerals. For example the sampling system may comprise a drilling system to collect a sample from on or beneath the sea bed.

Referring now to Figure 5a, this shows a block diagram of a smart trap system 500. The smart trap system 500 comprises a buoy which includes an electronics subsystem 520. The electronic subsystem incorporates a communication interface to communicate with a base station 510 located on a boat and to communicate with traps 530. The electronic subsystem may also comprise a microprocessor, stored program memory, a power supply such as a battery, and optionally a GPS location device. The buoy also includes a GPS location device enables reporting of the location of the buoy and of the traps attached to the buoy.

Each trap comprises a trap controller 530 which includes a processor, sensors and a communications interface, and optionally a local power supply (not shown). Each trap 530 in the smart trap system is connected to another trap using either a chain or a rope 540 forming a chain of traps. In the example, there are only two traps in the chain however the number of traps can be increased or decreased according to user requirements. The traps in the chain are further connected using a wired electrical connection to carry power and data. The end trap of the chain is connected to the buoy via the chain or rope 540. There is an electrical connection between the buoy and the end trap. This connection allows the data to be carried from the traps to the buoy and/or power from buoy to the traps.

In use the electronics sub-system 520 of the buoy collects and processes data obtained from the chain of traps and updates the base station 510 with a status of the each of the traps in the chain. The data obtained from a trap may comprise data relating to a condition of the trap, for example as previously described, such as whether or not the trap has captured any catch, and/or a condition of bait in the trap, and/or a trap identifier. The base station has a user interface to present this information optionally in conjunction with the location of the buoy and/or of the traps attached to the buoy.

In implementations of the system a base station 510 may additionally or alternatively be located on land, for example at a fixed computing device at a control station and/or at a mobile computing device such as a mobile phone, for example for hobbyist use. The system may provide user interfaces of the type shown in Figure 5b for example for professional use 550, research 560, or hobby use 570.

Some examples of traps which may be used with a system as described above, or which may be used independently of such a system, are now described.

Thus referring now to Figure 6, this shows an example of an underwater snail trap. The snail trap 600 comprises a first half 605 of a hinged body part and a second half 610 of the hinged body part which are fastened together form a tubular body part 620 defining a tube. The hinged body part may be the same as described later with reference to Figure 7.

The two halves 605, 610 of the hinged body part may be fastened together with a rubber strap. The tubular body part is rigid which facilitates a modular, reconfigurable construction, as described later.

Access doors 615 may be located on the walls of the tube 620 to remove captured snails from the trap. Additionally or alternatively the captured snails may be removed from the trap by unfastening the first half of the hinged body part 605 from the second half of the hinged body part 610.

A funnel shaped entrance part 625 is located at one end of the tube 620 and a mesh element 635 (Figure 6b) is located at the other end. In this example the funnel shaped entrance part 625 is removable from the tube 620. The funnel shaped entrance part 625 has an aperture at the apex for the snails to enter the trap and escape holes 630 for undersized crab/lobster catch (when used in its crab/lobster mode). This is explained further later. Thus one or more holes may be provided on each sloping surface of the funnel and/or one or more holes may be provided at the apex of the funnel.

Figure 6b shows an open view of the snail trap of Figure 6a. In this view the first half 605 of the hinged body part and the second half 610 of the hinged body part are unfastened to show an internal configuration of the snail trap which includes the mesh element 635 and weights (Figure 8b).

When the trap is in use and aligned vertically the weights are located at the bottom end of tube 620 adjacent the seabed and the funnel shaped entrance part 625 is at top of tube 620. The weights ensure that the trap stands upright. For example one or more weights may be mounted on each half of the hinged body part. The weights may be evenly distributed around the bottom of the trap. For example the weights may be disposed circumferentially around the bottom of the tube 620 for example adjacent the mesh element 635. Figure 7 shows an example crab/lobster trap 700. In some implementations the crab/lobster trap 700 is made from parts which can be dismantled and reassembled into at least one, in implementations two snail traps. More specifically the body part, funnel part, mesh part and weights from two snail traps may be assembled into a single crab/lobster trap of the type illustrated. The snail trap and crab/lobster traps may have different orientations on the sea bed.

As the traps may be used independently different reference numerals have been given to like elements. However the skilled person will recognise that parts which have been given different reference numerals may be the same part when used to provide a combined, that is reconfigurable snail trap and crab/lobster trap. That is, to take an example, the funnel shaped entrance part 725 described below may be the same part as the previously described funnel shaped entrance part 625, and so forth.

The illustrated crab/lobster trap 700 comprises a first hinged body part 705 and a second hinged body part 710 which are locked to together form an extended tube 720. The locking mechanism of the two hinged body parts is further described later with reference to Figures 9a to 9c. Each of the hinged body parts 705, 710 may be used to fabricate a snail trap as described previously.

The extended tube 720 may have doors 715 in its walls for removal of the trapped catch. Additionally or alternatively the extended tube 720 may be opened as shown in Figure 7b to remove the trapped catch. A funnel shaped entrance part 725a, b, is located at each end of the extended tube 720 which allows the catch to enter the trap. The operation of the funnel-shaped entrance part is described later. In implementations each funnel-shaped entrance part 725a, b may be provided with a respective escape aperture 730a, b. The escape aperture is configured to allow undersized catch to escape from the trap. It may be of a standard size for such purposes, e.g. with a minimum dimension of 2, 3, 5, 8 or 10cm; one European standard requires a minimum diameter of 8cm.

Figure 7b shows an open view of the reconfigurable snail and crab/lobster trap of Figure 7a. Two mesh elements 735a and 735b are joined together to form a mesh frame 735. Bait may be placed within the mesh frame to attract the catch, for example, crabs or lobsters, into the trap. One or more weights 740a, b may be fitted into grooves 745 provided in the hinged body parts 705, 710. In the crab/lobster trap configuration the trap is placed on the seabed oriented horizontally with the funnel shaped entrance parts located near the seabed. The one or more weights 740a, b are located in the bottom half of the extended tube 720 to help maintain the trap in a horizontal orientation with respect to the seabed.

The snail trap described in Figure 6a, 6b may be transformed into the above described crab/lobster trap by joining together the hinged body parts of two snail traps and reconfiguring the weights.

Figures 8a-8d show individual parts which may be used for the traps of both Figures 6 and 7. For convenience the parts are given different reference numerals but the same parts may be used for each trap.

Thus Figure 8a shows half of a hinged body part 800 with an access door 805 and hinge 810; two of these halves may be fastened together to define a tube. Figure 8b shows an example of weights 815 configured to fit into a groove of the half hinged body part 800. The shape of the weights may conform to a shape of the wall of the tube. Figure 8c shows an example of mesh element 820 which has perforations 825 which allow the water to flow through. The mesh element may be made of plastic and may be moulded in one piece. Figure 8d shows a self-supporting funnel shaped entrance part 830 with integrated escape apertures 835. The funnel shaped entrance part may be made of flexible material such as plastic and may be moulded in one piece. Providing some flexibility in the funnel facilitates a one-way passage of catch into the trap as described later. The funnel shaped entrance part 830 may define a central aperture (not shown) along the length of bottom 840 of the funnel.

It will be appreciated that the parts illustrated in Figures 8a-8d allow the construction of different types of modular trap. This is advantageous because the same individual body parts can be assembled together to form various trap configurations depending on the requirements of a user. This provides a flexible and cost effective way for configuring traps.

Figures 9a to 9c illustrate joining a first hinged body part 905 and a second hinged body part 910, for example of the type previously described, to provide an extended tube such as extended tube 720. These figures also illustrate a mechanism by which the parts are locked together.

The first hinged body part 905 has locking pins perpendicular to a longitudinal edge 920 of the hinged body part which engage with corresponding formations, for example apertures 925, on the second hinged body part 910. When both hinged body parts 905, 910 are open completely i.e. at 180° the locking pins 915 may be aligned with the corresponding formations. The formations/apertures of the second body 910 part can then be slid over the pins. The joined hinged body parts may then be hinged shut to define a tube to lock the parts together.

Figure 9b shows an end view of the first and second hinged body parts 905, 910 when the hinged body parts are in a completely open configuration, as the second body part is slid over the pins. Figure 9c shows an end view when the hinged body parts 905, 910 are in a closed configuration to form a tube. In the closed configuration the pins on either side of a hinge of the first body part 905 point in opposite directions such that the first and second body parts are automatically locked together in a longitudinal direction. That is, there is no longer any single direction in which one body part can be moved relative to the other to release the body parts.

Referring again to Figure 9a, this shows a formation 930 which defines a ramp leading up away from an inside surface of the trap. Referring back to Figure 7b, this ramp is positioned so that it leads up to aperture 730a, facilitating undersized catch leaving the trap via aperture 730a. In implementations there is no aperture under the ramp, which might otherwise provide an alternative escape route of less well defined size.

As shown in Figure 9a, such a ramp may be provided on each half of the hinged body. Similarly a funnel-shaped entrance part 725a, b may have an escape aperture on each of two opposite surfaces - that is funnel-shaped entrance part 725a may have a counterpart to the escape aperture 730b, though this is not clearly visible in the figure. The trap may lie on the bottom on either of its larger faces, that is as shown in Figure 7b or upside down as compared with Figure 7b. Providing a ramp and escape aperture on each hinged body/funnel half facilitates escape of undersize catch when the trap is in either of these orientations. Referring again to Figures 6-8, and in particular to Figure 8d, in some implementations the funnel shaped entrance part (“funnel”) comprises a pair of opposed surfaces 850 defining a longitudinal aperture at their apex through which catch may enter the trap. The surfaces, which in implementations are approximately flat and define a V-shape, may be joined at their respective edges by joining pieces 860.

As previously described the funnel may be formed of flexible material such as rubber or plastic, which has some resilience. In this way catch may force its way in through the longitudinal aperture, which opens as the catch enters, but the catch is inhibited from returning the same way. In implementations the funnel is made of a rubbery material which allows it to be turned inside out to facilitate emptying the trap, in particular without opening the trap. This is particularly suitable for emptying a snail trap as the snails may be poured out of the trap without opening the trap.

Referring again to Figure 6, escape holes for undersized catch are important when catching crab/lobster. This presents a problem in a trap intended for both types of catch since there is a risk that snails could escape through these relatively large holes. However by locating the escape apertures on the sides of the funnel portion of the funnel-shaped entrance part this risk is reduced as when the trap is in its vertical configuration, as shown in Figure 6, snails find it difficult to leave via the escape holes. Nonetheless when the trap is lying horizontally undersized crab/lobster catch can easily leave the trap, especially when a ramp leading up to the escape aperture is provided.

Referring again to Figure 7a, the trap may be provided with fixtures such as holes 750 to allow the trap to be attached to a chain or rope, for example so that traps may be strung out in a line as previously described. The trap may also be provided fixtures such as holes 760 to allow one or more sensors or sensor mounts to be attached to the trap, for example to sense a condition of the trap and/or bait as previously described. The trap may also be provided with one or more holes 770 arranged so that water flushes through the trap as the trap is lifted to the surface. This helps to remove dirt and smaller, unwanted sea creatures. These holes may be located, for example, at opposite sides of the trap so that when the trap is lying on the bottom, one hole is at the top of the trap and another is at the bottom of the trap. These holes should be small enough to inhibit the escape of catch; for example they have the form of slots, as shown. Optionally they may be sized as to facilitate the escape of undersized crab/lobster catch. Corresponding notches may be provided in the edges of the weights, mesh, and funnel-shaped entrance part, as shown in Figures 8b-8d, so as not to obscure these holes. As shown in Figure 9a, additional holes 940 may serve a similar purpose (these are not shown to scale in the Figures and may be sized to inhibit the escape crabs/lobsters that are not undersized). In some other implementations the holes 940 are covered by the formation 930 and thus do not provide a way out of the trap; they may be used to lift the trap. Although the hinged body parts for joining are shown in Figure 9a as different, in some other implementations they may be the same. In some implementations the trap may have a broadly hexagonal cross-section, as shown. This hexagon may have a pair of opposite sides that are longer than the others, that is a pair of opposite faces of the trap may be broader than the other faces. This helps the trap to adopt a predetermined orientation when deployed in its crab/lobster configuration, in particular an orientation in which the opposed surfaces of the funnel (that is the surfaces defining a longitudinal aperture at their apex) form a ramp up from the bottom, e.g. sea floor, to allow crabs/lobsters to enter the trap: If the trap lands on one of its shorter, i.e. narrower faces it will tend to fall over onto its broader face. The escape aperture, where present, is also adjacent the bottom of the trap and the ramp leads up from the bottom to the escape aperture. A hexagonal configuration can also increase the strength of the trap and facilitates the hinged arrangement described. In some other implementations, however, the trap may have a broadly square or rectangular cross-section, which can facilitate stacking of the traps.

No doubt many other effective alternatives will occur to the skilled person. It will be understood that the invention is not limited to the described embodiments and encompasses modifications apparent to those skilled in the art lying within the spirit and scope of the claims appended hereto.

Claims

CLAIMS:

1. A reconfigurable snail and crab/lobster trap, the trap comprising:

first and second hinged body parts, wherein each hinged body part is hinged along a longitudinal edge so that the body part can be opened, or hinged shut to define a tubular body part;

wherein the first and second hinged body parts are longitudinally joinable to define an extended body unit;

a funnel shaped entrance part for a first end of each of the body parts;

one or more weights for a second, opposite end of each of the body parts;

wherein the reconfigurable snail and crab/lobster trap is configurable as a snail trap in which one of the body parts is hinged shut to define the tubular body part, and wherein the funnel shaped entrance part is located at a first end of the tubular body part and the one or more weights are located at a second end of the tubular body part such that in use, the snail trap is vertically orientated with the second end on the water bed and the first end displaced away from the water bed with the funnel shaped entrance part facing upwards; and

wherein the reconfigurable snail and crab/lobster trap is configurable as a crab/lobster trap in which the first and second hinged body parts are longitudinally joined and hinged shut to define the to define extended body unit, and wherein one of the funnel shaped entrance parts is located at each end of the extended body unit and the one or more weights are located in an inner region of the extended body unit such that in use the crab/lobster trap is horizontally orientated with the funnel shaped entrance parts is located near the water bed.

2. A reconfigurable snail and crab/lobster trap as claimed in claim 1 wherein the first body part has pins perpendicular to the longitudinal edge which engage with corresponding formations on the second body part so that the second body part can be slid over the pins when the first and second body parts are hinged open, and wherein when the first and second body parts are hinged shut the pins on either side of a hinge of the first body part point in opposite directions, such that when hinged shut the first and second body parts are longitudinally locked together.

3. A reconfigurable snail and crab/lobster trap as claimed in claim 1 or 2 wherein each of the hinged body parts comprises first and second half tubes hinged along the longitudinal edge, and wherein each of the half tubes is configured to mount the one or weights in two arrangements, a first arrangement for the snail trap in which the one or more weights are circumferentially disposed at the second end of the tubular body part and a second arrangement for the crab/lobster trap in which the one or more weights are disposed on one of the half tubes.

4. A reconfigurable snail and crab/lobster trap as claimed in claim 1 , 2 or 3 further comprising a removable mesh part configured to be mounted at the second end of each tubular body part such that when the reconfigurable snail and crab/lobster trap is configured as a crab/lobster trap the mesh parts, when mounted, define a bait cage.

5. An underwater snail trap comprising:

a funnel shaped entrance part to funnel the snails into the trap, the funnel shaped entrance part defining one or more holes to allow snails to enter the trap;

a rigid enclosure for trapped snails, openable to retrieve the trapped snails; wherein the funnel shaped entrance part is located at a first end of the enclosure; and

wherein one or more weights are located at a second, opposite end of the enclosure such that, in use, the snail trap is vertically orientated with the second end on the water bed and the first end displaced away from the water bed with the funnel shaped entrance part facing upwards.

6. A reconfigurable snail and crab/lobster trap or underwater snail trap as claimed in any preceding claim wherein the or each funnel shaped entrance part has one or more funnel side surfaces converging towards a funnel apex, and one or more escape apertures in the one or more funnel side surfaces to allow undersize crab/lobster catch to escape, such that the trap is usable as both a snail trap and a crab/lobster trap.

7. A lobster/crab/snail trap system, comprising:

at least one trap for catching and retaining lobsters, crabs and/or snails;

a buoy;

a chain or rope linking the at least one trap to the buoy; and

a wired electrical connection linking the at least one trap to the buoy;

wherein the at least one trap comprises one or more sensors to sense a condition of the trap; wherein the buoy includes an electronic subsystem, coupled to the trap via the wired electrical connection to harvest data derived from the one or more sensors and communicate trap condition data representing the condition of the trap to a base station.

8. A trap system as claimed in claim 7 comprising a chain of the traps, linked by a respective chain or rope and wired electrical connection, wherein an end trap of the chain is linked to the buoy, wherein the electronic subsystem is configured to harvest data from each trap relating to a condition of the trap and communicate the condition of each of the traps to the base station.

9. A trap system as claimed in claim 8 wherein each trap includes a sensing system comprising the one or more sensors, a processor to communicate with the electronic subsystem, and may have a trap identifier, and wherein the electronic subsystem is configured to harvest the data derived from the one or more sensors and to communicate trap condition data in association with the trap identifier for identified trap to the buoy/base station.

10. A trap system as claimed in claim 7, 8 or 9 wherein the one or more sensors to sense a condition of the trap include one or more of a camera, a movement sensor, and a depth sensor.

1 1. A trap system as claimed in any one of claims 7 to 10 wherein the buoy includes a global positioning system (GPS) sensor to report a location of the at least one trap.

12. A trap/system as claimed in any preceding claim including locomotion means to move the trap laterally and/or vertically, and a trap electronic controller to receive control commands and to control the locomotion means to move the trap in response to the control commands.

13. A trap/system as recited in any preceding claim wherein the trap is made of material which slowly dissolves in sea water.

14. An underwater positioning system for a trap, the positioning system comprising: an attachment for attaching the trap;

locomotion means to move the trap laterally and/or vertically;

an electronic controller, coupled to a communications interface to receive control commands, and to control the locomotion means to move the trap in response to the control commands.

15. An underwater positioning system as claimed in claim 14 wherein the locomotion means comprises one or more propellers.

16. An underwater positioning system as claimed in claim 14 or 15 further comprising one or more positioning sensing devices, and wherein the electronic controller is configured to determine position of the trap in response to a signal from said one or positioning sensing devices.

17. An underwater positioning system as claimed in claim 16 wherein the one or more positioning sensing devices include one or more of a global positioning system (GPS) sensor, a light sensor, and a camera.

18. An underwater positioning system as claimed in any one of claims 14-17 further comprising one or more trap condition sensing devices, and wherein the electronic controller is configured to determine a condition of the trap in response to a signal from said one or trap condition sensing devices.

19. An underwater positioning system as claimed in any one of claims 14-18 wherein the electronic controller is configured to perform a sequence of movement operations in response to a local or remote signal to automatically move the trap to a new trap position in response to trap relocation request.

20. An underwater positioning system as claimed in claim 19, further comprising a system to detect depletion of target stock in a location of the trap to generate the trap relocation request.

21. An underwater positioning system as claimed in claim 19 or 20 wherein the electronic controller is configured to autonomously move the trap to a new trap position without needing an external control signal.

22. An underwater positioning system as claimed in any one of claims 14-21 wherein the electronic controller is configured to move the trap automatically into an optimal position.

23. An underwater positioning system as claimed in any one of claims 14-22 further comprising rotation means to rotate the trap about the attachment; wherein the rotation means is configured for control by the electronic controller.

24. An underwater positioning system as claimed in any one of claims 14-23 wherein the trap is configured to catch a species based on one or more of: weight, size, type and gender.

25. An underwater positioning system as claimed in any one of claims 14-24 wherein the electronic controller is configured to return the trap to the surface automatically after a pre-specified time, or in response to an external signal, or where the positioning system includes a self-abort security mechanism to return the trap to the surface when an abort condition is detected.

26. An underwater positioning system as claimed in any one of claims 14-25 in combination with the trap used for fishing.

27. An underwater positioning system as claimed in claim 26 wherein the trap is configured to catch a plurality of different species of animal, and wherein a different a part of the trap is allocated to trapping each of the different species.

28. An underwater positioning system as claimed in claim 26 or 27 wherein a light is attached to the trap to attract and trap a bait species in the trap, and such that the bait species attracts a target species to the trap.

29. An underwater positioning system as claimed in claim 26, 27 or 28 wherein the trap further comprises one or more supports to support the trap at a location which is displaced away from the sea floor, whereby the trap is configured to catch a target species and to restrict other species entering the trap.

30. An underwater positioning system as claimed in any one of claims 26-29 wherein the underwater positioning system is operable in a swarm mode wherein a plurality of underwater positioning systems work in coordination with each other to move their respective traps.

31. An underwater positioning system as claimed in any one of claims 14-30 wherein the trap is configured to self-attach to an anchor.

32. An underwater positioning system as claimed in any one of claims 14-31 further comprising a sampling system to collect a sample from the sea and/or sea bed.