NO341433B1 - Fishing tackle and method of making the same - Google Patents

Description

According to a first aspect, the present invention relates to a method for producing a fish bait in accordance with the preamble to patent claim 1. According to a further aspect, it relates to a fish bait produced by the method.

When fishing, it has been proven that the possibility of catching fish, be it sport fishing or professional fishing, can be increased considerably by adding aroma substances, so-called attractants, which have an attractive effect on fish. Such lures can be used in connection with both live and artificial bait.

Such agents are known, among other things, from ZA 8 206 790 A, which deals with artificial bait comprising added flavorings and dyes to act as an attractant to fish. A mixture of cereal grains, water and hardened fat is included in the bait as an aromatizing substance. Hydrolyzed vegetable protein and polyhydric alcohols are used to enhance the attractive effect on fish. The hydrolysis of protein from marine resources is not discussed. The effect of the bait against one or more species of fish is also not discussed or exemplified.

From US 2003 06623IA, a degradable, artificial bait for fish based on natural, biodegradable components is known. Hydrolyzed fish proteins, fish oil, fish meal, crustaceans from the seabed, mussels from the seabed, fish powder, fruit, spices, garlic, garlic oil, neutral L-amino acids can be components of the bait. A special effect of hydrolyzed fish protein or other hydrolysed protein from marine resources as bait is not discussed. The effect of the bait on one or more species of fish is also not discussed or exemplified.

US Patent No. 4,704,286 A describes a flavored fish bait based on a water-soluble polymer with a slow dissolution rate. The preferred polymer is polyvinyl alcohol with a predetermined degree of hydrolysis of its ester groups to achieve the desired rate of solubility. It may take the physical form of a sheet comprising parallel slits. The flavoring agent consists of gelatin hydrolyzate and beef extract and the gelatin hydrolyzate is made by pancreatic digestion of gelatin. The hydrolysis of protein from marine resources is not discussed. The effect of the bait against one or more species of fish is also not discussed or exemplified.

US patent application 2004088901 describes a sport fishing system consisting of a rod and reel, including fishing line, at least one artificial or natural bait and a controlled release fish attractant for application to said artificial or natural bait. The hydrolysed protein from marine resources is not mentioned as a fish bait.

It is a significant challenge to produce fishing bait with lures (attractants) that can be produced at a low cost, that are effective overtime, that release attractant at the right rate to be effective immediately and yet retain the effect over time, and that do not washes out quickly in contact with water.

Purpose

It is an object of the present invention to provide an attractant which meets all the challenges mentioned above.

Present invention

The above-mentioned purposes have been achieved through the present invention which, according to a first aspect, comprises a method as stated in patent claim 1.

According to another aspect, the invention comprises a fishing bait as stated in patent claim 16.

Preferred embodiments of the invention appear from the independent patent claims.

By "slowly soluble (or degradable) in water" is meant that an exposed block of the polymeric material with a thickness of 2 cm will not completely dissolve in salt water or fresh water in less than a minimum of 2 hours and more preferably 2 days. Preferably, such a block will be completely dissolved after less than approx. 2 months.

Further details of the invention with reference to the attached figures

Figure 1 schematically shows a section of parts of a first embodiment of an apparatus suitable for carrying out the method according to the present invention. Figure 2 schematically shows a section of parts of a second embodiment of an apparatus suitable for carrying out the method according to the present invention. Figure 3 schematically shows a section of parts of a third embodiment of an apparatus suitable for carrying out the method according to the present invention. Figures 4a and 4b show cross-sections of two varieties of fish bait produced by an embodiment of the method according to the present invention. Figures 5a and 5b show cross-sections of two varieties of fish bait produced by another embodiment of the method according to the present invention. Figures 6a and 6b show cross-sections of two varieties of fish bait produced by a third embodiment of the method according to the present invention. Figures 7a and 7b show cross sections of two variants of fish bait produced by a fourth embodiment of the method according to the present invention Figure 8 shows another cross section of a variant of a fish bait produced by an embodiment of the method according to the present invention. Figure 9 shows a cross-section of a variant of the fishing bait produced by the embodiment which also produced the fishing bait shown in Figure 4b. Figure 1 schematically shows a section of a form of extruder head 11 suitable for use when carrying out the method according to the present invention. The extruder head 11 has two supply channels, a central tubular channel 12 and a channel 13 arranged around this, both of which open into a joining zone 14 where supplied material is given the opportunity to solidify using one or more mechanisms described in more detail below. To the right of the extruder head 11 is shown a cross-section 15 of the fish bait which leaves the extruder head 11 in the state it has during solidification. It is clear from the cross-sectional shape that the central channel 13 has the shape of a tube with a circular cross-section and that the channel 14 has the shape of an annular slot coaxial with the channel 13. Figure 2 shows schematically, similarly to Figure 1, a section of a form of extruder head 21 with two supply channels, a central tubular channel 22 and a channel 23 arranged around this, both of which open into a joining zone 24 where supplied material is given the opportunity to solidify using one or more mechanisms described in more detail below. To the right of the extruder head 21 is shown a cross-section 25 of the fish bait which leaves the extruder head 21 in the state it has during solidification. As can be seen from the cross-section 25, the cross-section of the channels 22 and 23 is slightly irregular.

In general, one can say about the profile shown in figure 2 that a first side of the cross section has a first shape and a first extent, while an opposite side of the cross section has a second shape and extent that are different from the first shape and extent, so that a fluid flow across the bait will create a Bernoulli effect with an overpressure on one side and a negative pressure on the opposite side, similar to the flow of air around an airplane wing.

A person skilled in the art will appreciate that still other cross-sectional profiles can be obtained by changing the cross-section of the channels 22 or 23, or even just replaceable nozzles (not shown) where the liquid components enter the coalescing zone 24.

Figure 3 shows a third variant of an extruder head 31 suitable for use when carrying out the method according to the present invention. The extruder head 31 itself is in principle similar to the variants shown in figure 1 and figure 2. The cross-section of the channels 32 and 33 is not shown and may be similar to that in figure 1 or that in figure 2 or they may also have other cross-sectional shapes. The distinctive feature of the variant shown in Figure 3 is that there are supporting walls or a supporting enclosure for the material entering the joining zone 34 and likewise a supporting enclosure in a subsequent stabilization zone 37 downstream of the joining zone 34. Figure 3 also shows means 36 that surround the material in the joining zone and which is suitable for accelerating solidification.

The means 36 can consist of UV lamps which are suitable for accelerating the solidification of material which solidifies under UV illumination, there can be means which are suitable for cooling the material in the joining zone, means suitable for heating the material in the joining zone or means for removing volatile constituents from the joining zone 34, through the application of a negative pressure in the zone. A combination of such means can also be used, for example both means for heating the material and means for removing volatile components.

It should be understood that in all the variants shown in figures 1-3, the bait is typically produced in the joining zone (14, 24, 34) as a longitudinally continuous extruded object which can then be divided into desired lengths or thicknesses.

Figure 4a shows a cross-section of a product in the form of a fishing bait 45 which is fundamentally similar to the cross-section 15 shown in Figure 1. The dark, circular component 46 comprises the attractant which is suitable for luring fish, while the ring-shaped component 47 is a component with the ability to solidify. It is clearly preferred that the component 47 has the ability to solidify relatively quickly, for example within seconds or a few minutes when it is exposed to conditions that favor solidification. Component 46 can also, in addition to the attractant, comprise material that hardens. As shown in Figure 4a, the attractant is evenly distributed in component 46 and there is little or no mixing of components 46 and 47.

While the fishing bait 45 leaves the joining zone as an endless "sausage", it is later typically sliced across the direction of movement, that is, with a cut as shown in Figure 4a. Figure 4b basically shows the same as Figure 4a, but with a different cross-sectional shape of the fishing bait. The desired cross-section can be achieved through the use of channels with this cross-sectional shape, or it can be achieved through mechanical action of the fishing bait (as shown in Figure 4a) immediately downstream of the joining zone, that is, before the stiffenable component 47 has fully stiffened. Figures 5a and 5b show in principle the same as Figures 4a and 4b, except that the attractant in this case is not present as a homogeneous suspension, but as discrete microcapsules distributed in component 56. Component 57 is the component with the ability to solidify under conditions. The advantage of microcapsules can be to prevent premature leaching of attractant from the product, that is to say make it easier to manage a slow release of attractant.

Figures 6a and 6b show a product variant where, like the case shown in figures 5a and 5b, the attractant is present as microcapsules, but here the final product is uniform over its entire cross-section, i.e. there is no longer any boundary between the first and second component after the second component has hardened. For this, a slightly different type of equipment is required than the extruder shown in figures 1-3. For example, a bunch of inner channels (12, 22, 32) can be used which are distributed within the cross-section of one larger channel (13, 23, 33).

Figures 7a and 7b show yet another variant of the product resulting from the method according to the present invention, where attractant is supplied partly as a homogeneous suspension, partly in the form of microcapsules. The advantage of this can be to achieve both a rapid immediate release of attractant, while at the same time, with the help of the microcapsules, more reliably maintaining control over how long the attractant is available for release. Figure 8 shows a variant that has much in common with the variant shown in Figure 6b, but where the concentration of the attractant gradually decreases from a high concentration near the center of the cross-section to a lower concentration near the outer parts of the product's cross-section. Figure 9 shows a cross-section of a variant of the fishing bait shown in Figure 4b. What is distinctive about the variant shown in Figure 9 is that a form of reinforcement 98 is arranged along the length of the product which adheres to the stiffenable/stiffened component 97. In other embodiments, the reinforcement 98 can enclose larger or smaller parts of the circumference of the product, and has the purpose of giving greater physical strength to the bait, so that it does not easily detach from the hook to which it is attached during fishing. The reinforcement 98 can sit on the outside as shown in the figure, alternatively flush with the surface of component 97 or inside component 97. The reinforcement can also be applied with an "excess" that hangs loosely at the rear edge of the bait and when moving through the water will flutter and cause the bait to appear more lifelike.

The reinforcement (98) is attached to at least part of the circumference of the polymer matrix of the bait before it has fully solidified, and is preferably fed continuously to the joining zone (14, 24, 34) at the same time as the liquid components to thereby avoid an extra step in the manufacturing process. The reinforcement (98) typically consists of a polymeric material in a form selected from foils, films, non-woven mesh, woven mesh. The material for the reinforcement (98) is preferably selected from among paper, cardboard, silk, modified and unmodified cellulose, polyamide, polyester, polyvinyl alcohol, polyacrylic acid, cotton, viscose.

Figure 10 shows a piece of bait placed on a hook during active fishing, where the direction of movement is from right to left. The shape of the bait causes a flow along the surface of the bait such that a slight negative pressure occurs on the upper side of the bait due to the curved shape which means that water flowing over the bait on its upper side has a longer path to pass and thereby passes the bait at a greater speed than the water passing under the bait. Greater speed results in lower pressure. Thereby, the bait as a whole gets a certain buoyancy in the water as a result of the movement and will move up towards shallower water depths at increased speed.

More about the hardenable component

The liquid, solidifiable component typically comprises a polymer or polymer-forming monomers and/or oligomers. The specific chemistry of the component can be chosen depending, among other things, on which mechanism is preferred for the solidification process. Relevant compounds for the hardenable component include, but are not limited to, monomers, oligomers and/or polymers of: acrylics, carbohydrates, saturated and unsaturated alcohols, saturated and unsaturated esters, carboxylic acids, epoxides and amines.

Examples of the stiffening component and method of stiffening

The hardening process and the apparatus

The solidification process can be carried out in a number of different ways, primarily depending on the selected polymer for the second liquid component. Thus, the hardening can be initiated, among other things, through temperature increase, temperature reduction, evaporation of solvent, UV lighting or the use of peroxide.

The apparatus can advantageously include tubular organs as shown in figures 1-3. The tubular members may open into a jointing zone, but it may be preferred that the outer tube continues some distance beyond the jointing zone and helps to stabilize the joined material during the solidification process.

In the joining zone, the material can, for example, be subjected to quenching to initiate solidification.

In another alternative, UV light is used to harden the polymer and thereby the entire joined material. In combination with this, tubular bodies can be used which are transparent at least in the joining zone.

The fishing bait shown in figures 6, 7 and 8 has no distinction between a first and a second component after the bait has been manufactured and solidified. The apparatus for producing bait in this form may comprise a tube with an opening corresponding to the cross-section of the bait. Encapsulated attractant dispersed in at least one other liquid component capable of solidification is forced or pumped through the tube followed by curing. The expert in the field will choose per se known methods and materials for encapsulating the attractant. The expert will also choose the thickness of the encapsulation shell so that the capsules are stable enough to survive pressure and shear forces during the manufacturing process and at the same time have the ability to release the attractant through the encapsulation shell during the use of the bait in fishing. Capsules can be selected from millicapsules, microcapsules and nanocapsules and comprise capsule diameters from typically 50 nm to typically 20 mm.

In relation to all embodiments, it should be noted that the liquid component containing the attractant before joining with the other liquid component may also contain material capable of solidifying under given conditions. This hardening process can take place under different conditions and with a different hardening rate than the hardening of the other component.

The shape and density of the bait can be important in various contexts. A preferred variant of the fishing bait according to the present invention has an outer cross-sectional shape as shown by figures 4b, 5b, 6b, 7b, 8, 9 and 10.

The point of this shape is to allow the bait to gain buoyancy in the water during movement, by creating a local underpressure on the upper side of the bait and a local overpressure on the underside of the bait, according to Bernoulli's principle of connection between pressure and movement. Furthermore, the density of the bait can be adjusted so that it is balanced in relation to the density of water. It is, for example, undesirable for the bait to lie on the seabed if it is not moving, since in that case it will quickly be eaten by bottom fish, crabs or other marine organisms that you are not interested in fishing.

More about the attractor phase

Preparation of attractant from shrimp according to the invention

Shrimp shells from hand-peeled shrimp were delivered frozen in 10 kg blocks from Lyngen Reker AS. The shell was stored at -20 °C at Nofima in Tromsø before use.

The enzyme Alcalase (Subtilisin) was supplied from Novozymes (Denmark) as a liquid concentrate. The enzyme activity was measured by adding enzyme solution to the substrate (8% dissolved casein). The reaction was stopped after 60 minutes by the addition of trichloroacetic acid, and remaining amino acids and peptides were measured spectrophotometrically according to Lowry's method. Before use, proteolytic activity was measured at 60% of the maximum activity measured in newly purchased Alcalase. The activity measurement was based on the amount of enzyme added during the hydrolysis. The specific gravity of Alcalase was calculated to be 1.14 g/ml.

The pre-filtration was carried out with a bag filter from Allied Filter Systems Ltd, England, of the type WE100P2VWR (lOOpm). The ultrafiltration was carried out with two new polyethersulfone (PES) membrane filters of the type PES2-383875AN-OX5A with a total filter surface of 13.6 m2, and a pore size of 3000 Dalton. The membranes were supplied by Due Miljø AS, and rinsed well with water in the filter system before use. Dry matter measurements during the production process were carried out with a Brix meter, and temperature was measured with an electronic temperature meter. Dry matter measurements on the final product were measured by drying at 105 °C to constant weight, and the amount of ash and organic matter was determined after combustion at 550 °C to constant weight.

Shrimp shells (300 kg) were thawed and tempered for two days by placing 10 kg frozen blocks outside in a cold room at 4 °C. The reactor equipped with an agitator was filled with hot water (approx. 80 °C) and mixed with shrimp shells (300 kg) to a total weight of 800 kg and a final temperature of 50 °C. The mixture was added with Alcalase to a final concentration of 1.14% (w/w) (or 1% (v/w)), and the reaction was allowed to proceed for 4 h at a uniform temperature of 50 °C.

After a reaction time of 4 hours, the enzyme was inactivated by heating the mixture to 80 °C using indirect steam. The heating to 80 °C took a total of approx. 3 hours. The reactor was then covered and allowed to stand for approx. 16 hours. The water phase was then drained off and separated from the undissolved shell through a coarse sieve at the bottom of the reactor. The temperature in the tank after standing for approx. 16 hours was 58 °C. A total of 550 kg of water phase with a solids content (TS) of 8% measured with a Brix meter was drained.

Before the ultrafiltration, the water phase was filtered through a bag filter (100 µm) to remove as much particulate matter as possible. Little solid matter was observed in the filters. The filtered water phase was pumped into the feed tank for the ultrafiltration plant. The temperature was then 50 °C and correctly adjusted in relation to the filters in the ultrafiltration facility.

The water phase was ultrafiltered in a nine-egg filter from GEA Liquid Processing Scandinavia AS (GLPS Combi Pilot Plant-Type R) with two polyethersulfone membranes, as previously specified, with a pore size corresponding to 3000 Dalton. The pressure difference over the filter surface (AP) was kept at approx. 1 bar, and the temperature was controlled to 50 °C. A pore size of 3,000 Dalton means that all molecules with a molecular weight of less than 3,000 must pass through the filters, while larger, not hydrolysed, proteins will be retained. The phase that passes through the filters (the permeate) was collected for further concentration by evaporation. The filtration rate through the filters was good, and 530 kg of permeate was collected during a period of approx. 2.5 hours. Early in the filtration period, the dry matter in the permeate was measured with a Brix meter at 5%, while later in the filtration period it was measured at 7.5%. The concentrate (retentate) is the fraction that did not pass through the filters, but was concentrated in the filter system. The retentate amounted to 23.5 kg and had a solids content of 11.8% at the end of filtration.

The permeate (530 kg) was evaporated into an Alfa-Laval Convap 6x3 evaporator under a vacuum of 0.6 bar and a temperature of 60-65 °C. Evaporated water amounted to 112 kg/hour, and evaporation continued to a residual quantity of 60 kg of final product. The dry matter content of the final product was measured at 58% with a Brix meter. The final product was stored in a cold room at 4 °C.

The example shows that hydrolyzate according to the invention can be produced in industrially relevant quantities with shrimp as raw material.

In a similar way, attractant from mussels, capelin or other marine raw materials can be produced.

The attractant included in the first liquid component can be of any type and nature, as long as it does not adversely affect the mixing or solidification process. Attractants produced through processes involving the hydrolysis of naturally occurring material from marine raw materials may be of particular interest. Preparation of such material exclusively through homogenization of the material is another alternative.

Microcapsules

In some embodiments, the attractant can be present as so-called microcapsules which are distributed or dispersed in the first liquid phase prior to the joining. The purpose of using capsules is to obtain a more controllable release of attractant over time and the possibility of extending the period of time in which the attractant is released. For this purpose, the capsule walls must form a barrier through which the attractant can pass, but only at a slow rate, and/or a barrier that gradually breaks down in the relevant environment, fresh water or salt water. Increased pressure (large water depths) can also significantly affect the capsules' stability and ability to retain the attractant over time.

Microcapsules can be produced through a number of different techniques, depending, among other things, on which size ranges are desired for the capsules. Non-exhaustive techniques for the production of microcapsules include spray drying, fluidized bed, so-called coacervation and "mechanical" capsule filling. Important features and several applications of such techniques are described in "Spray drying and encapsulation of omega-3 oils", Barrow, C. J. et al., Woodhead Publishing Series in Food Science, Technology and Nutrition (2013), 252, 194-225;

"Microencapsulation of Anthocyanins by Natural Biopolymers: A Review", Mahdavi, S. A. et al., Drying Technology (2014), 32(5), 509-518; "Encapsulation for preservation of functionality and targeted delivery of bioactive food components", de Vos, P. et al., International Dairy Journal

(2010), 20(4), 292-302; "Microencapsulation and its application", Harini, K. et al., Synthetic Fibres

(2007), 36( 1). 21-28.

Microcapsules of the smallest size are obtained by spray drying, the capsules can then be down to 10 pm and more typically from approx. 10 to approx. 130 p.m. By using a technique known as fluidized bed, capsules with a size of approximately 100 to 800 pm can be produced, with coacervation, capsules with a size of approx. 100 pm to 3 mm, and with a filling machine it is possible to produce capsules - typically with walls of gelatin - with sizes over 1 cm. Regardless of the size and type of capsules, it is important that the capsule material exhibits good adhesion to the polymer material of the hardenable component, in order to avoid that the presence of capsules introduces a series of fracture indications in the fishing bait and thereby reduces its mechanical stability.

Other preferred factors

A preferred embodiment of the invention is a fishing bait which consists of at least 80% water by weight. Such a bait is as similar as possible to a natural bait such as mackerel or herring, is more quickly soluble or degradable than fish bait with a lower water content and is less expensive to manufacture.

Another preferred embodiment of the invention is a fishing bait which consists of at least 5% by weight of a material with a density lower than 0.15 g/cm<3>. Such a bait has a lower density and thus a greater ability to lift from the bottom than a bait without material with a density lower than 0.15 g/cm<3>. Such a bait is less likely to be eaten by benthic animals, which results in the loss of the bait.

When it is stated that at least one component with the ability to solidify is added, this means that more than one component with the ability to solidify can be added in a mixture or separately. For example, a further component with the ability to solidify can be supplied via a further annular channel which lies outside and encloses the first annular channel which is shown in figures 1-3.

Joining of the at least two components in the joining zone takes place in a way that involves coextrusion of the components.

The solidified material is soluble or decomposable in water, but preferably slowly soluble or alternatively slowly decomposable, as explained above.

The first liquid component, i.e. the component comprising the attractant, can also contain at least one component with the ability to solidify.

Claims (19)

Patent requirements 1. Method for the production of fishing bait designed for the slow release of attractant in an aqueous environment, the production comprising combining in a sammenföringsone (14, 24, 34) at least one first liquid component that comprises the attractant with at least one second liquid component that has the ability to harden, in such a way that the attractant in the fishing bait is surrounded by the harden, polymer material, characterized in that a reinforcement (98) is attached to at least part of the perimeter of the polymer matrix before it has finished harden. 2. Method in accordance with patent claim 1, characterized in that the second liquid component with the ability to solidify comprises a material selected from monomers, oligomers and polymers, with the ability to form a solidified polymer matrix. 3. Method in accordance with patent claim 1, characterized in that the joining takes place in a way that involves coextrusion of the at least two components. 4. Method according to patent claim 1, characterized in that the components are supplied to the sammenföringsonen (14, 24, 34) in separate channels, an inner channel (12, 22, 32) which supplies the first liquid component and an outer channel (13, 23 , 33) which supplies the second liquid component and which encloses the inner channel. 5. Method in accordance with patent claim 1, characterized in that the solidified material is soluble in water. 6. Method in accordance with patent claim 1, characterized in that the solidified material is degradable in water. 7. Method in accordance with patent claim 4, characterized in that the inner channel (12, 22, 32) can comprise a bundle of two or more channels. 8. Method according to any one of patent claims 1 to 7, characterized in that at least parts of the attractant are supplied in the form of capsules selected from millicapsules, microcapsules and nanocapsules. 9. Method according to any one of patent claims 1 to 8, characterized in that the bait is produced in the sammenföringssonen (14, 24, 34) as a longitudinally continuous extruded object which is then divided into desired lengths or thicknesses. 10. Method in accordance with patent claim 1, characterized in that the reinforcement (98) is continuously fed to the joining zone (14, 24, 34) at the same time as the floating components. 11. Method according to patent claim 1 or 10, characterized in that the reinforcement (98) consists of a polymer material in a form selected from foils, films, non-woven network, woven network. 12. Method according to any one of patent claims 1, 10 to 11, characterized in that the material for the reinforcement (98) is selected from among paper, cardboard, silk, modified and unmodified cellulose, polyamide, polyester, polyvinyl alcohol, polyacrylic acid, cotton, viscose. 13. Method according to any one of claims 1 to 12, characterized in that the material for the second component with the ability to solidify is selected from monomers, oligomers and polymers of: acrylics, carbohydrates, saturated and unsaturated alcohols, saturated and unsaturated esters, carboxylic acids, epoxides, amines. 14. Method according to any one of patent claims 1-13, characterized in that the first liquid component comprising the attractant also contains at least one component with the ability to solidify. 15. Method according to any one of claims 1 to 8, characterized in that the bait (45, 55, ...95) before it is fully hardened, is shaped so that its cross-section across the direction of movement through the tubular members is elongated and asymmetrical in that a first side of the cross-section has a first shape and a first extent, while an opposite side of the cross-section has a second shape and extent that are different from the first shape and extent, so that a fluid flow across the bait will create a Bernoulli effect with overpressure on one side and underpressure on the opposite side, corresponding to the flow of air around an airplane wing. 16. Fishing bait (45, 55, ...95), comprising a first component comprising an attractant for fish and a second, hardened component surrounding the first component, characterized by also comprising a reinforcement (98) attached to at least part of the perimeter of the outer polymer material. 17. Fishing bait (45, 55, ...95) in accordance with patent claim 16, characterized in that the attractant is at least partially in the form of microcapsules. 18. Fishing bait (45, 55, ...95) in accordance with one of the patent claims 16 to 17, characterized in that the fishing bait consists of at least 80 percent by weight of won. 19. Fishing bait (45, 55, ...95) in accordance with one of claims 16 to 18, characterized in that the fishing bait consists of at least 5 percent by weight of a material with a density lower than 0.15 g/cm<3>.