ES2556223B1 - Device and attractor method of sharks - Google Patents

Abstract

Device and attractor method of sharks. The device (13) comprises: # - an electromagnetic module for the generation of an electromagnetic field by means of the electrical excitation of two metal electrodes in contact with the water by means of an electric pulse generating unit in a frequency range of 1-8 Hz; # - an optical module with a light pattern generating unit in a band between 440-560 nanometers of wavelength; # - an acoustic-vibrating module with an acoustic transducer element responsible for generating vibrations in the water and a unit frequency generator for the emission of submarine acoustic pulses configurable in frequency, amplitude and duration, in a bandwidth between 50 Hz — 20,000 Hz; # - an olfactory-gustatory module with a lyophilized compound from a selection of fishmeal, pheromones and blood for the stimulation of olfactory and gustatory receptors of sharks (1).

Description

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Device and attractor method of sharks DESCRIPTION

Field of the invention

The present invention is included within the field of underwater systems of attraction of marine species by stimulating their sensory organs.

Background of the invention

At present, the accidental fishing of shark in tuna fisheries both through the purse seine art, and through the longline art is a first level ecological problem. This problem is increased in the particular case of purse-seine fisheries through the use of floating objects for the aggregation of tunas (FAD, '' Fish Aggregating Device "). These systems not only attract tuna shoals, but also its natural predators among which are the sharks.

During the fishing maneuver, if there is any accidental capture, sharks usually die before their return to the sea is possible and in those cases in which the animal is still alive and its return to the sea it is possible the damage caused to the animal can result in a significant decrease in their chances of survival.

Several families of sharks are in a situation where their immediate future is seriously threatened and is a top-notch issue in all governmental and non-governmental forums. This discussion is especially important for the species Silky Tiburon (Carcharhinus faciformis) and the Oceanic Whitetip Shark (Carcharhinus longimanus), which are the most threatened by this type of fisheries.

Developments are known for the study of electromagnetic interaction with fish in general, but none of the devices studied solves the problem of accidental fishing of sharks.

Patent documents US20120199079-A1, US6837182-B2, and US5566643-A disclose devices that use electromagnetic waves to repel sharks and thus drive away beach shark and generally remove them from human presence.

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Many of the marine animals have developed physiological mechanisms that generate light, that is, some parts of their bodies are bioluminescent. The light is generated thanks to a biochemical reaction that takes place in organs called photophores. In the production of light there are several possibilities depending on the molecules involved in the reaction, although the pair formed by luciferin / luciferase or photoproteins are normally involved. Luminescent devices used for the attraction of fish are known, for example those disclosed in US5388039-A and WO2008151476-A1, particularly useful for night fishing.

The present invention helps to solve this problem by attracting the sharks out of the usual fishing area and, therefore, avoiding accidental fishing. The present invention comes to solve said problem and to cover a real need within the fishing sector that guarantees the sustainability of the environment.

Description of the invention

The present invention presents a solution that overcomes the limitations described above, being an autonomous device capable of attracting the sharks located distances greater than 2000 meters from the anchoring point of the device, by the combined stimulation of all its sensor organs. It must be taken into account that with the electromagnetic and optical stimulation, used by other devices, a maximum coverage radius of approximately 100 meters is obtained. This distance is not enough to attract, maintain and separate sharks from tuna fishing gear, which have an approximate radius of 500 meters (fence art).

In the present invention a circuit has been developed capable of generating electromagnetic emission patterns through two metal zinc electrodes integrated in the fuselage of the device. The voltage does not exceed 100 nV since a higher voltage can produce repulsive effects instead of attraction. In addition, the generator circuit works at a frequency of 8 Hz, which has been studied as the frequency that generates the greatest intensity of attraction in the sharks, unlike most fish that begins to reduce its effectiveness of attraction from 5Hz In the invention, the metal of the electrodes plays an important role, since the electrodes are zinc and allow to continue generating a small electromagnetic field when the electric generator module stops sending controlled pulses of electrical energy to the electrodes.

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The microprocessor controls this electromagnetic module and begins generating preprogrammed electromagnetic patterns at a voltage around 100 nV. This allows that at the beginning of activating and operating the device the electromagnetic coverage is of greater intensity and therefore of greater radius of action under water and sharks that are far away can easily detect these attractive pulses. After a while, around 10 minutes, the microprocessor gives the order and the system generates pulses at a lower voltage, around 50nV. Subsequently, around 20 minutes after its initial connection, the generator starts to emit in 5nV and remains so for an additional time, around 20 more minutes. From this moment (about 40 minutes in total) the electric pulse generator stops and only the electromagnetic field generated by the zinc electrodes is maintained. The times to activate the different voltages on the electrodes are programmable.

With this mode of actuation it is first possible to attract sharks that are far away and then keep them close to the device while maintaining their attraction towards it, without generating the repulsion that would occur if high voltages were maintained.

In the present invention an optical module is also used that generates light patterns in a band between 440 and 560 nanometers of wavelength. The bioluminescence of the beings of the marine environment is generated in lengths that go between 440-560 nm, that is, it is greenish blue light, and therefore most of the marine bioluminescence is concentrated in the wavelengths where the maximum optical transparency of seawater. The wavelength that best propagates in the marine environment and that reaches a greater range, from the point of its emission, is 480 nm. To reach great distances in the marine environment without having to emit at great intensity this wavelength is used, since the generated light will reach greater distance, it will look better, it will arrive with greater intensity and therefore it will be more useful for the purposes of shark attraction.

The present invention also takes into account that normally bioluminescence does not occur continuously, but generates an intermittent light with various patterns. This is due to a compromise between the function for which it is generated and the need for it, simultaneously, to be difficult to locate by predators. An intermittent light is seen as easily as a constant light, but it cannot remain the same and therefore

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much gives more chances of evasion. In some cases the light is emitted for prolonged periods, but for camouflage purposes, and thus some species keep the ventral part illuminated so that predators do not detect their silhouette by observing them from the bottom.

The optical module controls the intensity in the emission of LED elements, not exceeding the threshold marked by the light generated by other animals through their bioluminescent organs, from 30 to 450 milliwatts of power for each light unit or LED. An increase in this intensity produces repulsion instead of attraction to sharks. The optical module also employs a program of random emission patterns to increase the attraction.

The developed device can be considered as non-polluting or intrusive for the marine environment since, on the one hand it is manufactured with components that do not generate direct contamination in the marine environment while the device remains in the water.

Likewise, once submerged he could find himself in a situation in which he could not be recovered for some reason, either by sinking after the attack of sharks, well motivated by extreme weather conditions, etc. For this case, all the elements that make up the system are either biodegradable or comply with RoHS (Restriction of Hazardous Substances). The electric accumulators used are based on low pollution elements for the marine environment.

A first aspect of the present invention relates to a shark attractor device comprising:

- an electromagnetic module for the generation of an electromagnetic field by means of the electrical excitation of two metal electrodes in contact with the water by means of an electric pulse generating unit in a frequency range of 1 to 8 Hz;

- an optical module with a unit generating light patterns in a band between 440 and 560 nanometers of wavelength;

- an acoustic-vibratory module with an acoustic transducer element responsible for generating vibrations in the water and a frequency generating unit for the emission of submarine acoustic pulses configurable in frequency, amplitude and duration, in a bandwidth between 50Hz-20,000Hz.

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The device may also comprise an olfactory-gustatory module with a lyophilized compound from a selection of fishmeal, pheromones and blood for the stimulation of olfactory and taste receptors of sharks.

In one embodiment, the device comprises a wireless communications module for the remote configuration of the acoustic, electromagnetic and optical patterns generated by their respective modules.

The electromagnetic module preferably comprises a microprocessor responsible for generating an electrical pulse of a determined intensity and voltage that is repeated periodically according to a preprogrammed pattern.

The metal electrodes of the electromagnetic module are preferably zinc. The excitation voltage applied to the metal electrodes of the electromagnetic module is preferably less than 100nV. The excitation voltage applied to the electrodes is preferably decreasing over time. The generating unit of the electromagnetic module is preferably configured to generate electrical pulses at a frequency of 8 Hz.

The optical module generating unit is preferably configured to generate light patterns at a wavelength of 480 nm. 10. The optical module may be configured to generate a flashing light with a program of preprogrammed emission patterns. The optical module preferably comprises a plurality of LEDs with a controlled emission power of 30 to 450 milliwatts.

A first aspect of the present invention relates to a method for attracting sharks, which comprises:

- the generation of an electromagnetic field by means of the electrical excitation of two metal electrodes in contact with water by means of electric pulses in a frequency range of 1 to 8 Hz;

- the generation of light patterns in a band between 440 and 560 nanometers of wavelength;

- the generation of vibrations in the water and the emission of submarine acoustic pulses configurable in frequency, amplitude and duration, in a bandwidth between

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50Hz-20,000Hz

The method preferably comprises the stimulation of olfactory and gustatory receptors of sharks by a lyophilized compound from a selection of fishmeal, pheromones and blood.

The excitation voltage applied to the metal electrodes is preferably less than 100nV and decreases over time.

Brief description of the drawings

A series of drawings that help to better understand the invention and that expressly relate to an embodiment of said invention that is presented as a non-limiting example of this is described very briefly below.

Figure 1A shows a front view of the shark attractor device according to the present invention. Figure 1B shows an exploded view of the device elements. Figure 1C shows the complete device with the shielding and clamping elements in transparent vision.

Figure 2 shows the approximate distances of detection of different stimuli by the sharks.

Figure 3 shows a schematic of the booster circuit of the acoustic-vibratory module.

Figure 4 shows a diagram of the frequency generator of the acoustic-vibratory module.

Figure 5 shows the vibration elements of the shark attractor device.

Figure 6 represents the shallow lateral line of the shark, capable of detecting pressure variations.

Figure 7 shows an electromagnetic generator scheme.

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Figure 8 shows the distribution of the Lorenzini blisters on the shark's head.

Figure 9 shows the distribution of electromagnetic fields generated by fish.

Figure 10 shows the behavior of sunlight under water.

Figure 11 shows the scheme of the optical module.

Detailed description of the invention

The attractor device of sharks 13, shown in Figure 1A-1C, is composed of four main modules (acoustic-vibratory module, electromagnetic module, optical module, olfactory-gustatory module) controlled by a central unit, which directly stimulate the different organs Sensitive (acoustic, electromagnetic, optical and olfactory-gustatory) of the sharks in order to attract them to the place where the device is activated.

The exploded view of Figure 1B shows the different elements of the attractor device 13:

- Upper closure cap 1.

- Frame 2 of electronics and electric accumulators.

- Tubular shield 3.

- LED luminous elements 4 of the optical module.

- Nickel-steel 5 bi-metal ring of the electromagnetic module.

- Organic bait filter crown 6 of the olfactory-gustatory module.

- Electromagnetic acoustic transducer 7 of the acoustic-vibratory module

- Perforated plate 8.

- Elastomeric membrane 9.

- Anti-torsion pressure washer 10.

- Closing ring 11.

- Acoustic bugle 12.

Figure 2 shows the approximate distances of stimulus detection by the sharks 1. The electrical stimuli, around 50 cm; visual stimuli, changes in pressure and smell, around 100 m; acoustic stimuli, one or several kilometers.

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The acoustic-vibratory module is composed of a frequency generating unit (Figures 3 and 4) working in a bandwidth between 50Hz-20,000Hz and an acoustic transducer element (Figure 5) with the ability to generate vibrations in the water emulating to those that produce with the movement some wounded fish (prey of the sharks) or similar to those that generate the fish in certain states of stress due to situations of fight or by actions of predation.

It is important to mention that the acoustic signal, transmitted in wave form, travels around four times faster than in the atmosphere since the density of water is 800 times greater than that of air. Therefore, the presence of the device is detected in a few seconds by the sharks that are within a radius of approximately 5,000 meters.

The acoustic generator circuits developed are based on microprocessor architecture to exercise independent control and manage from energy consumption to the times and amplitudes of acoustic emissions, so that the emission of underwater acoustic pulses at different frequencies, amplitude and duration; adequate stimuli to attract the sharks.

The mode of operation of the acoustic-vibratory module is described below. Once the device detects contact with water through a sensor incorporated in the fuselage, it automatically starts the internal counter of the central microprocessor. When it reaches the assigned value programmed by the developed software, the microprocessor orders to emit the acoustic pulse. Previously, it is necessary to generate a very high amplitude voltage pulse to excite the transducer that generates the acoustic pulse. This is achieved by a tension booster element 10 shown in Figure 3, which raises the supply voltage to the required value. The voltage required to drive the transducers has a very wide range, which can range from 1.5v to 30 volts, depending on the amplitude and duration of the pulse you wish to emit, as well as the type of transducer used.

To achieve the maximum transfer of pulse emitting power to the transducer, multiple passive electronic components (impedances, capacitors and resistors) are necessary. In this way the impedance, capacitance and output inductance of the circuit is adapted to the piezoelectric ceramic. Figure 4 shows a circuit scheme

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emitter of the acoustic pulse by means of microprocessor 12. In the diagram you can see the connector 14 that is used for programming the microprocessor (this function is performed in fabrication and in updates made by authorized technical personnel).

The acoustic-vibratory module also has an acoustic transducer element 15, shown in Figure 5, with the following elements:

- Shielding of the acoustic transducer 15, made of polypropylene.

- Elastomer bellows 16.

- Transfer disk 18.

- 20 magnet neodymium internal transducer assembly.

- Electric winding 22.

- Container - winding anchor 24.

It is a low frequency sound generation system by electromechanical procedures based on combined systems of rare earth solenoids and magnets (neodymium). The electrical circuit described above in Figure 4 controls by means of electrical pulses the position of the neodymium element 20, which is in contact with the transfer disk 18, which vibrates and moves according to the internal programming of the microprocessor 12.

The sharks combine two types of sensors to detect this acoustic signal, auditory sensor and pressure sensor.

With respect to the auditory sensor, the sharks have a very sensitive auditory organ to interpret the sounds underwater at distances greater than one kilometer. In sharks the ear is barely visible from the outside. You can only see two small pores in the head that constitute a connection of the inner ear with the outside world. The inner ear is quite similar to that of mammals: it consists of three semicircular canals and four sensory epithelia (membranes).

With respect to the pressure sensor, the lateral line 2 (shown in Figure 6) is a sensory organ that is present in most fish, including sharks 1. It is used to detect movement and vibration under the surrounding water. Shark 1 uses this sense to detect moving organisms, especially injured fish.

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The lateral line 2 records the movement and changes of water pressure. As in the auditory sensor, this detection is converted into a nerve signal and then transmitted to the central nervous system. Sharks use their lateral line system to measure the pressure gradient along the longitudinal axis of their lateral lines.

The electromagnetic module is composed of an electric pulse generating unit in a frequency range of 1 to 8 Hz, with a controlled voltage ranging from 100nV to 5nV. It incorporates architecture based on a microprocessor, similar to that applied in acoustic devices, becoming the central microprocessor who controls this module. The pulses are transmitted to the water by two metal zinc electrodes that are in contact with the water. The module emulates the electromagnetic fields that generate different species of fish and other marine animals. And it allows to attract the sharks over short distances and make them stay close to the device, even when they have ascertained that it is not food.

Thus, the control is similar to that of the acoustic modules but with some notable differences. It is mainly based on the generation of an electric pulse of determined intensity and voltage that is repeated periodically according to a random pattern controlled by a microprocessor.

The electromagnetic field is generated around two metallic elements, both in permanent contact with water. When the microprocessor orders it, the circuit closes producing a potential difference between them. This gives rise to the generation of a pulse or, what is the same, a certain amount of electrical energy that is distributed in the water in a certain omnidirectional way.

The range of radius depends on the emission power, as well as the pulse duration. The microprocessor controls the duration period and the instant of the pulse firing time by means of a counter and through a power stage transistor. On the other hand, the power or amplitude of the electric pulse is adjusted according to the curve of the transistor chosen and the amplifiers used.

Figure 7 shows the electromagnetic generator scheme of the electromagnetic module, with a DC-DC voltage converter 32 and a microcontroller 30. Contacts 34 and 34 ’are part, together with transistor Q2, of a switch that allows

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Microprocessor 30 is fed and the generator circuit is put into operation when contacts 34 and 34 ’come into contact with water. The microprocessor 30 generates the pulses according to the programmed patterns, commanding the transistor Q1.

All living beings emit small discharges during the contraction of the muscles. Sharks have the best sensitivity to electricity among all known animals. This sense is used by the shark to find prey by detecting its nerve impulses. Sharks can perceive even slight muscle movement of animals at a distance of approximately one meter. For this they have specialized structures located in the head and mouth (particularly in the lower part of the head, snout and nose), called Ampules of Lorenzini 3, shown with points in Figure 8. Ampules of Lorenzini 3 they are modified electroreceptive sensors that serve to detect electric fields and variations in them. They are small indentations in the head of the shark 1, which form channels filled with gel that range from a pore in the skin to a blister inside the body, forming a network around the head. The blister has nerve endings that apparently go through the mixed nerve to the anterior antlers of the spinal cord, the caudal portion of the cerebellum's atria and the middle brain. The gel that fills the channels of the Lorenzini 3 ampoules is a substance formed mainly by glycoprotems and they have low electrical impedance (the same electrical resistivity as seawater). At the end of the inner channel, there is a cavity with the electric receptors capable of recording a potential difference through the skin.

Figure 9 shows the distribution of electromagnetic fields generated by a fish 5 in motion. The shark is able to detect changes in voltage, in the range of 0-8 Hz, of only 5nV / cm, that is, 5nV considering a measurement in a 1cm ampoule. This corresponds to a 12V battery at a distance of 12 km under the sea. From the comparison of the neuronal signals of many blisters in an area of the skin, a sensory signal shows the presence of a source of tension.

The optical module is composed of a unit generating light patterns emitted by an array of LEDs in a band between 440 and 560 nanometers of wavelength. This module emulates the light pulses produced by some marine animals through their bioluminescent organs and that serve to communicate with each other, help in the capture using their bioluminescence as a soil and to emit warning signals to predators.

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The behavior of light underwater is different than in the air. When sunlight falls on the surface of the sea, around 5% is reflected, and the rest is transmitted through water, a fraction is eventually absorbed by water and by the chemical and organic components in suspension. Figure 10 shows the behavior of sunlight under water, where 45% of the light that hits surface 9 reaches 1 meter, 16% of the light reaches 10 meters and only 1% of the light It reaches 100 meters. Underwater, greenish blues prevail (in the range of approximately 500 to 560 nm).

Shark senses are well adapted to these special conditions. The eyes of sharks are very similar to human eyes, with the cornea, iris, pupil, lens and retina. Shark vision is about seven times better than human vision, allowing them to see distances of 150 meters in good condition.

Figure 11 shows the electronic scheme of the optical module for the activation of one of the LEDs of the optical module, where the voltage booster 40 serves to command LED elements from voltages below 2.7V.

The olfactory-gustatory module is a lyophilized compound of a selection of fishmeal, pheromones, blood and other products capable of stimulating the olfactory and taste receptors of sharks.

The nasal cavities located at the bottom of the shark's head have an opening for each entree and flowing out of the water, which passes the sensitive tissue with its fine sensory cells located behind. Odorous substances dissolved in the flow of water through the sensory cells and are subject to the receptors of those cells. This in turn triggers a series of mechanisms that ultimately produce a signal that will be sent to the central nervous system. Smells are still processed in the telencephalon (anterior brain).

Sharks can detect the presence of a molecule at a concentration of 1 part per 25 million parts of water and can smell blood at distances of hundreds of meters. The sense of smell is particularly important for sharks. It is known that a large part of the frontal brain is used for the processing of olfactory information. Sharks selectively react to certain odors.

The oceanic attractor device for sharks is used in very diverse marine environments where the acoustic, electromagnetic and optical patterns generated by the invention must be varied in order to obtain the greatest effectiveness against the different species of sharks 5 (they can react differently to the stimuli). For this, the device is designed to incorporate a wireless programming system, which can be easily reprogrammable using a Bluetooth ™ contactless technology through an app installed on a mobile phone, tablet or PC.

Claims (15)

5 10 fifteen twenty 25 30 35 1. Attracting device of sharks, characterized in that it comprises: - an electromagnetic module for the generation of an electromagnetic field by means of the electrical excitation of two metal electrodes in contact with the water by means of an electric pulse generating unit in a frequency range of 1 to 8 Hz; - an optical module with a unit generating light patterns in a band between 440 and 560 nanometers of wavelength; - an acoustic-vibratory module with an acoustic transducer element responsible for generating vibrations in the water and a frequency generating unit for the emission of submarine acoustic pulses configurable in frequency, amplitude and duration, in a bandwidth between 50Hz-20,000Hz. 2. Attracting device of sharks according to revindication 1, characterized in that it comprises an olfactory-gustatory module with a lyophilized compound of a selection of fishmeal, pheromones and blood for the stimulation of olfactory and gustatory receptors of sharks (1) . 3. Attracting device for shafts according to any of the preceding claims, characterized in that it comprises a wireless communications module for the remote configuration of the acoustic, electromagnetic and optical patterns generated by their respective modules. 4. Attracting device for shafts according to any of the preceding claims, characterized in that the metal electrodes of the electromagnetic module are zinc. 5. Attracting device according to any of the preceding claims, characterized in that the electromagnetic module comprises a microprocessor responsible for generating an electric pulse of a determined intensity and voltage that is repeated periodically according to a preprogrammed pattern. 6. Attracting device according to any of the preceding claims, characterized in that the excitation voltage applied to the metal electrodes of the electromagnetic module is less than 100nV. 5 10 fifteen twenty 25 30 35 7. Attracting device according to any of the preceding claims, characterized in that the excitation voltage applied to the electrodes is decreasing over time. 8. Attracting device for shafts according to any of the preceding claims, characterized in that the generating unit of the electromagnetic module is configured to generate electrical pulses at a frequency of 8 Hz. 9. Attracting device for shafts according to any of the preceding claims, characterized in that the generating unit of the optical module is configured to generate light patterns at a wavelength of 480 nm. 10. Attracting device according to any of the preceding claims, characterized in that the optical module is configured to generate an intermittent light with a program of preprogrammed emission patterns. 11. Attracting device for shafts according to any of the preceding claims, characterized in that the optical module comprises a plurality of LEDs with a controlled emission power of 30 to 450 milliwatts. 12. Method for attracting sharks, characterized in that it comprises: - the generation of an electromagnetic field by means of the electrical excitation of two metal electrodes in contact with water by means of electric pulses in a frequency range of 1 to 8 Hz; - the generation of light patterns in a band between 440 and 560 nanometers of wavelength; - the generation of vibrations in the water and the emission of submarine acoustic pulses configurable in frequency, amplitude and duration, in a bandwidth between 50Hz-20,000Hz. 13. Method for attracting sharks according to revindication 12, characterized in that it comprises the stimulation of olfactory and gustatory receptors of sharks (1) by a lyophilized compound from a selection of fishmeal, pheromones and blood. 14. Method for attracting sharks according to any of claims 12 to 13, characterized in that the metal electrodes of the electromagnetic module are zinc. 15. Method for attracting sharks according to any of claims 12 to 14, characterized in that the excitation voltage applied to the metal electrodes is less than 100nV. 16. Method for attracting sharks according to any of claims 12 to 15, characterized in that the excitation voltage applied to the electrodes is decreasing over time.