RU2810000C1 - Method for installing gill nets at arbitrary depths in lakes - Google Patents

Abstract

FIELD: fisheries.

SUBSTANCE: installation of gill nets at an arbitrary depth in lakes is carried out by installing a net cloth, equipped with weights on the bottom and floats on the top, from a watercraft. A basic buoy station is installed, consisting of a load weighing 15-50 kg, a halyard with a diameter of 7-10 mm and a buoy with a volume of 5 to 15 liters, by immersing it in water to the bottom of the reservoir, and the halyard on which the locking knot is tied goes vertically down without inlet, and the distance from the stopper assembly to the bottom corresponds to the installation horizon of the gill net. The lower harness in the form of a thread on which the lower cells of the gill net are strung is attached to the halyard of the base buoy station using a metal or plastic roller connected to the gill net using a metal removable connecting device in the form of a bracket weighing up to 30 g, to which a load is attached up to 1 kg. The upper harness in the form of a thread on which the upper meshes of the gill net are strung is attached to the halyard of the base buoy station with a metal carabiner weighing up to 30 g. Then the gill net is installed by moving the craft in the required direction or drifting with the wind, every 5-10 meters at the bottom of the gill net, attach a leash from a halyard with a diameter of 4-5 mm with a load of 1 kg with a length corresponding to the distance selected on the halyard from the bottom to the locking unit. At the end of the gill net, a leash with a load of up to 1 kg is attached to the lower catch, and a float of up to 1 liter with a leash made from a halyard with a diameter of 4-5 mm is attached to the upper one.

EFFECT: improving the efficiency of catching freshwater fish in open parts of lakes at an arbitrary depth.

1 cl, 1 dwg

Description

The invention relates to the field of fisheries and is aimed at increasing the efficiency of catching freshwater fish in open parts of lakes at an arbitrary depth.

The means of labor in industrial fishing are fishing vessels, fishing mechanisms, and fishing gear. They are called technical means of catching fish and are combined into a fishing system. Of the means of labor, only fishing gear is used directly for catching fish. Consequently, industrial fishing tools are tools intended directly for catching fish and non-fish objects from water bodies.

The set of techniques and methods for catching fish is called the technological process of catching fish. Depending on the technical means used and the features of the technological process, fish can be caught using the same fishing gear in different ways. Thus, fishing methods differ in both technical means and methods of performing fishing operations. From the systematic approach to the fishing process, it follows that the basis of fishing is the management of technical means of catching fish and the fished object, and that the main task of the science and practice of industrial fishing is to optimize control systems for the fishing process and their operating mode.

Today, fixed nets, which are classified as gill fishing gear, are used for industrial fishing. This category includes fixed nets (anchor nets), floating nets, sweep nets and fixed nets (on stakes). The principle of operation of gill nets is based on entangling or getting stuck (entangled) fish in a mesh fabric placed in the path of its movement.

A fixed network is known, consisting of one or more mesh fabrics attached to the upper and lower selections. The upper selection is equipped with floats for nets, and the lower, if necessary, with weights. By design, fixed networks are divided into single-walled, edge-to-edge (double-walled) and framed. Fixed nets are most often connected in several pieces, forming a net order, which is installed motionlessly in the water area with the help of guy ropes, weights and anchors. They are installed on the surface of a water body, in the water column or at the bottom. The lower selection of the net is equipped with weights, and the upper selection - with floats. The required size of the float and weights depends on the amount of planned catch and installation methods. If the net is installed at the bottom, the sinking force of the loads must be higher than the buoyancy of the floats, which in this case stretch the net fabric. A certain reserve of buoyancy will not lower the catch to the bottom (Fixed nets for industrial fishing: types, features, fishing techniques, published on November 18, 2022, electronic resource at: https://www.magazine.fish/publikatsii/-promyslovoe-rybolovstvo/stavnye_seti_dlya_promyshlennogo_rybolovstva_tipy_ -osobennosti_tekhnika_lova/).

Existing schemes in the fishing industry for installing fishing nets in open waters at arbitrary depths involve the use of sinking nets and floats attached to ropes of a fixed length. The length of the float elements determines the depth of the gill net; they are attached at an equal distance to the upper selection. The scheme was developed for marine ecosystems where it is impossible to secure fishing gear to the bottom. This scheme has a significant drawback - when the wind direction changes, the ropes holding the floats get tangled with each other and, as a rule, collapse the net.

The technical result of the claimed method is to increase the efficiency of using the gill net by eliminating the collapse of the fishing gear and simplifying the repeated installation of the gill net in open parts of lakes at an arbitrary depth.

The technical result is achieved by the fact that the installation of gill nets at an arbitrary depth in lakes is carried out by installing a net cloth, equipped with weights on the bottom, and floats on the top, from a watercraft, while first installing a base buoy station consisting of a load weighing 15- 50 kg, a halyard with a diameter of 7-10 mm and a buoy with a volume of 5 to 15 l, by immersing in water to the bottom of the reservoir, while the halyard on which the locking knot is tied goes vertically down without overlap, and the distance from the locking knot to the bottom corresponds horizon of installation of the gill net, the lower selection in the form of a thread on which the lower cells of the gill net are strung is attached to the halyard of the base buoy station using a metal or plastic roller connected to the gill net using a metal removable connecting device in the form of a bracket weighing up to 30 g, to which a load of up to 1 kg is attached, the upper harness in the form of a thread on which the upper meshes of the gill net are strung is attached to the halyard of the base buoy station with a metal carabiner weighing up to 30 g, then the gill net is installed by moving the craft in the required direction or by drifting with the wind , and every 5-10 meters, a leash from a halyard with a diameter of 4-5 mm with a load of 1 kg is attached to the lower selection of the gill net with a length corresponding to the distance selected on the halyard from the bottom to the locking unit; a leash with a load is attached to the end of the gill net to the lower selection up to 1 kg, and to the top float up to 1 liter with a leash made of a halyard with a diameter of 4-5 mm. The method is carried out as follows: Installation of the gill net is carried out from a self-propelled floating structure with a waterproof hull - a watercraft (1) rowed or using a motor (see Fig. 1). Figure 1 shows a diagram of installing a gill net at an arbitrary depth.

At the first stage of installing the gill net (2), a base buoy station is installed at an arbitrary depth, which consists of a load (3) weighing 15-50 kg, a halyard (4) with a diameter of 7-10 mm and a buoy (5) with a volume of 5 to 15 l. The base buoy station is installed by immersing the load (3) in water to the bottom of the reservoir and so that the halyard (4) goes vertically down without overlap. When installing on the halyard (4), a locking knot (6) is tied so that the distance from the locking knot (6) to the bottom of the reservoir corresponds to the installation horizon of the gill net (2). The locking knot (6) limits the immersion of the lower edge of the gill net (2).

At the second stage of installing the gill net (2), its lower harness (the thread on which the lower meshes are strung) is attached to the halyard (4) of the base buoy station using a small metal or plastic roller (7) connected to the gill net (2) at using a metal removable connecting device in the form of a bracket (8) weighing up to 30 g. A small load (9) up to 1 kg is attached to it. The upper harness (the thread on which the upper meshes are strung) of the gill net (2) is attached to the halyard (4) of the base buoy station also with a small metal carabiner (10) weighing up to 30 g.

At the third (final) stage, the gill net (2) is installed by moving the craft (1) in the required direction or by drifting with the wind. Every 5-10 meters, a leash (11) with a diameter of 4-5 mm with a load of up to 1 kg from the halyard (4) is attached to the lower selection of the gill net (2), while the length of the leashes (11) corresponds in length to the length selected on the halyard (4 ) base buoy station the distance from the bottom of the reservoir to the stop unit (6). At the end of the gill net (2), a leash (12) with a load of up to 1 kg is attached to the lower catch, and a small float (13) of up to 1 liter with a leash (14) with a diameter of 4-5 mm from the halyard (4) is attached to the upper catch. The presence of the float (13) allows you to check the gill net (2) without removing the base buoy station and then reinstall the gill net (2) on the same base buoy station if necessary.

The use of this scheme for installing gill nets (2) allows for effective catching of semi-deep-sea, deep-sea and bottom fish in reservoirs (lakes, reservoirs, etc.) with unstable wind conditions at the required depth. The base buoy station fixes the position of the gill net (2) in the reservoir, and the locking unit (6) with a metal or plastic roller (7) ensures a stable position of the gill net (2) at a given depth. Thanks to the installation of leashes (11) with a weight attached to the lower gill net (2), the proposed design of setting the net does not allow it to collapse when the wind direction changes. This is also facilitated by the fact that most of the elements of the gill net (2), which can increase the windage of the structure, are under water.

Examples of method implementation

Example 1:

The method was tested and successfully applied in the study of the salmon fauna of Lake. Kronotsokoye (Kamchatka). Gill nets were installed at the bottom (50, 70, 100 meters) and in the depth (20, 40, 60 meters); the exposure time of the nets was 6 hours. In this case, at the first stage, a base buoy station was installed, the load (3) of which was 15, 35 and 50 kg, the diameter of the halyard (4) was 7, 8.5 and 10 mm and the buoy (5) with a volume of 5, 10 and 15 liters. The base buoy station was installed by immersing the weight (3) in water to the bottom of the reservoir and so that the halyard (4) went vertically down without overlap. When installing on the halyard (4), a stop knot (6) was tied in such a way that the distance from the stop knot (6) to the bottom of the reservoir corresponded to the installation horizon of the gill net (2). At the second stage of installing the gill net (2), its lower harness (the thread on which the lower meshes are strung) was attached to the halyard (4) of the base buoy station using a small plastic roller (7) connected to the gill net (2) using a metal a removable connecting device in the form of a bracket (8) weighing 20 g. A small load (9) weighing 0.5, 0.8 and 1 kg was attached to it. The upper harness (the thread on which the upper meshes are strung) of the gill net (2) was attached to the halyard (4) of the base buoy station also with a small metal carabiner (10) weighing 20, 25 and 30 g. At the third (final) stage, the gill net was installed net (2) by moving the craft (1) in the required direction or by drifting with the wind. Every 5 and 10 meters, a leash (11) with a diameter of 4 or 5 mm with a load of 0.5, 0.8 and 1 kg from the halyard (4) was attached to the lower selection of the gill net (2), and the length of the leashes (11) corresponded to its length was selected on the halyard (4) of the base buoy station from the bottom of the reservoir to the locking unit (6) and was 50, 70 and 100 meters. A leash (12) with a load of 0.5, 0.8 and 1 kg was attached to the end of the gill net (2) to the lower catch, and a small float (13) of 0.8 and 1 l with a leash (14) with a diameter of 4 was attached to the upper catch. and 5 mm from the halyard (4). Catches at the bottom ranged from 2 to 12 specimens. per linear meter of network, in thickness from 3-9 copies. per linear meter. This gill net installation scheme ensured a stable position of the gill net (2) at these depths for all 6 hours. The proposed design of the net did not allow it to collapse when the wind direction changed. Thanks to the effective use of this method, previously unknown deep-sea groups of char (Salvelinus malma) endemic to the lake were discovered. Kronotsokoe.

Example 2.

The method was used for fishing in the central part of the lake. Elgygytgyn (Chukotka). The nets were installed at the bottom at a depth of 170 meters. The exposure time of the networks was 12 hours. In this case, at the first stage, a base buoy station was installed, the load (3) of which was 50 kg, the diameter of the halyard (4) was 10 mm and the buoy (5) with a volume of 15 liters. The base buoy station was installed by immersing the weight (3) in water to the bottom of the reservoir and so that the halyard (4) went vertically down without overlap. When installing on the halyard (4), a stop knot (6) was tied in such a way that the distance from the stop knot (6) to the bottom of the reservoir corresponded to the installation horizon of the gill net (2). At the second stage of installing the gill net (2), its lower harness (the thread on which the lower meshes are strung) was attached to the halyard (4) of the base buoy station using a small metal roller (7), connected to the gill net (2) using a metal a removable connecting device in the form of a bracket (8) weighing 30 g. A small load (9) weighing 1 kg was attached to it. The upper harness (thread on which the upper meshes are strung) of the gill net (2) was attached to the halyard (4) of the base buoy station also with a small metal carabiner (10) weighing 30 g. At the third (final) stage, the gill net (2) was installed. by displacing the craft (1) by drifting with the wind. Every 10 meters, a leash (11) with a diameter of 5 mm with a load of 1 kg from the halyard (4) was attached to the lower selection of the gill net (2), and the length of the leashes (11) corresponded in length to the length selected on the halyard (4) of the base buoy station the distance from the bottom of the reservoir to the locking unit (6) and was 170 meters. At the end of the gill net (2), a leash (12) with a load of 1 kg was attached to the lower catch, and a small float (13) of 1 liter with a leash (14) with a diameter of 5 mm from a halyard (4) was attached to the upper catch. This gill net installation scheme ensured a stable position of the gill net (2) at these depths. The proposed design of the net did not allow it to collapse when the wind direction changed. The use of this method made it possible to find out that the central, deepest part of the basin is inhabited by longfin (Salvelinus svetovidovi) and smallmouth (Salvelinus elgyticus).

Claims (1)

A method for installing gill nets at an arbitrary depth in lakes, including installing a net cloth equipped with weights on the bottom and floats on the top, from a watercraft, characterized in that at the first stage a base buoy station is installed, consisting of a load weighing 15-50 kg , a halyard with a diameter of 7-10 mm and a buoy with a volume of 5 to 15 liters, by immersing in water to the bottom of the reservoir, while the halyard on which the locking knot is tied goes vertically down without overlap, and the distance from the locking knot to the bottom corresponds to the installation horizon gill net, the lower selection in the form of a thread on which the lower cells of the gill net are strung, is attached to the halyard of the base buoy station using a metal or plastic roller connected to the gill net using a metal removable connecting device in the form of a bracket weighing up to 30 g, to which attach a load of up to 1 kg, an upper harness in the form of a thread on which the upper meshes of the gill net are strung, attach it to the halyard of the base buoy station also with a metal carabiner weighing up to 30 g, then install the gill net by moving the craft in the required direction or drifting with the wind, Moreover, every 5-10 meters, a leash from a halyard with a diameter of 4-5 mm with a load of 1 kg is attached to the lower selection of the gill net with a length corresponding to the distance selected on the halyard from the bottom to the locking unit; a leash with a load of up to 1 kg, and to the top float up to 1 liter with a leash made of a halyard with a diameter of 4-5 mm.